Reagents. Mercury (II) nitrate 1-water. Specifications

3.3 Marking

3.3.1 Transport marking of barrels and bottles - in accordance with GOST 14192 with the application of the handling mark "Sealed packaging".

The marking characterizing the transport hazard of the cargo is according to GOST 19433 (class 8, subclass 8.1, classification number 8172, drawing 8/6 a), UN serial number 1789.

Table 1

3.3.2 A label made of plywood or thick cardboard, protected by an acid-resistant and moisture-proof shell, is attached to each barrel or bottle, on which the data characterizing the packaged product are applied:

Name of the enterprise and (or) its trademark;

Product name, brand, grade;

The designation of this standard;

Gross and net weight;

The number of the barrel or bottle and the total number of them in the lot.

3.3.3 Signs and inscriptions on tanks and containers are applied in accordance with the requirements of the "Rules for the Transport of Dangerous Goods" (Part 2, Section 41, 1987, Moscow).

3.4 Packaging

3.4.1 Technical synthetic hydrochloric acid is poured into special gummed tanks of the sender or recipient, rubberized containers, polyethylene barrels with a capacity of 50 and glass bottles with a capacity of 20 in accordance with the current regulatory documentation.

Glass bottles are packed in boxes of type V - 1, number 3 - 2 according to GOST 18573. Packaging must comply with GOST 26319.

3.4.2 It is allowed to pour the product into tanks and containers with hydrochloric acid residue, if the analysis of the residue confirms that its quality complies with the requirements of this standard. Otherwise, the residual hydrochloric acid is removed and the tank or container is washed.

Barrels and bottles must be dry and clean.

3.4.3 Filling hatches of tanks, containers and drum plugs should be sealed with rubber or polyethylene gaskets, both when sent to consumers (filled with acid), and when returned to the supplier of empty containers.

Bottle necks sealed with ground glass stoppers or screw caps should be wrapped with plastic wrap and tied with twine.

3.4.4 The level (degree) of filling of tanks, containers, barrels and bottles is calculated taking into account the maximum use of the carrying capacity (capacity) and volumetric expansion of the product with a possible temperature drop along the route.

4 Safety requirements

4.1 Commercial grade synthetic hydrochloric acid is a caustic liquid that is chemically stable.

In the air, it "smokes" as a result of the release of hydrogen chloride and its attraction of air moisture with the formation of acid fog.

Metals located in a series of voltages to the left of hydrogen (Al, Zn, Fe, Co, Ni, Pb, etc.) displace it from hydrochloric acid, which can lead to the formation of explosive hydrogen-air mixtures.

Safety measures - exclusion of contact of hydrochloric acid with these metals due to anti-corrosion coatings, purging with nitrogen and checking the gas phase from equipment and pipelines for explosiveness before hot work.

4.3 Hydrochloric acid mist irritates the upper respiratory tract and mucous membranes of the eyes. Contact with skin causes burns.

4.5 Technological processes production and use of hydrochloric acid and the production equipment used must comply with the requirements of sanitary rules N 1042-73.

Production facilities must be equipped with ventilation in accordance with GOST 12.4.021 and SNiP 2.04.05-91 and a water supply that meets the requirements of GOST 2874.

4.6 All work with hydrochloric acid should be carried out in overalls of type K50 in accordance with GOST 12.4.103 and in goggles of type G in accordance with GOST 12.4.013.

All workers must be provided with industrial filtering gas masks of grade B (PPE FGP, FG-130) in accordance with GOST 12.4.121.

4.7 In the event of a spill, hydrochloric acid is washed off floor surfaces and equipment large quantity water or alkaline solution. Sour wastewater before entering the general sewerage system, they must be neutralized at local treatment plants.

4.8 The fire is extinguished with the help of sprayed water and air-mechanical foam.

4.9 Substandard product is neutralized with an alkali solution. Gas emissions are captured and neutralized.

5 Acceptance

5.1 Technical synthetic hydrochloric acid must be presented for acceptance in batches.

A batch is any amount of hydrochloric acid, homogeneous in its qualitative composition, issued by one quality document.

The quality document must contain the following data:

Name and (or) trademark of the manufacturer;

Name of the product and its brand, grade, standard designation;

Batch number, date of manufacture;

Tank number, number of containers, barrels, bottles;

Net weight;

Classification code according to GOST 19433;

The results of the analysis carried out or confirmation of the quality compliance with the requirements of this standard.

5.2 To check the quality of hydrochloric acid, acceptance and periodic tests are carried out.

5.3 The manufacturer determines the mass fraction of arsenic periodically once a quarter.

5.4 During acceptance testing at the manufacturer, samples are taken from a commodity tank designed to fill containers.

To check the quality of hydrochloric acid, samples are taken from the consumer:

From each tank and container;

From 10% of barrels, bottles, but not less than three in batches of less than 10 barrels, bottles.

5.5 If unsatisfactory analysis results are obtained for at least one of the indicators, a reanalysis is carried out on a double sample or a newly selected sample from a tank, container, barrels, bottles.

The results of the reanalysis apply to the entire lot.

6 Methods of analysis

6.1 Point samples from the tank and tank are taken by slowly immersing a sampler of any design, made of acid-resistant materials, to the bottom of the tank, tank.

Point samples from barrels, bottles and containers are taken using a glass or polyethylene tube with a diameter of 10-15 mm with a drawn end.

A pooled sample is obtained by mixing equal volumes of incremental samples.

6.2 From a thoroughly mixed pooled sample, a sample is taken for analysis with a volume of at least 1, which is placed in a dry, clean bottle with a ground stopper or a polyethylene jar with a screw cap. A label is stuck on a bottle or plastic jar indicating:

Name of manufacturer and product;

Designations of this standard, brand and grade;

Dates and locations of sampling;

Batch numbers and dates of manufacture;

Name of the person who took the sample.

6.3 General instructions for analysis

During the analysis, the air temperature should be .

When weighing, general-purpose laboratory scales in accordance with GOST 24104 accuracy classes 2 and 4 should be used with the largest weighing limits of 200 and 500 g.

It is allowed to use imported utensils according to the accuracy class and reagents in quality not lower than domestic ones.

It is allowed to determine the density of hydrochloric acid according to Appendix B.

6.4 Appearance definition

The appearance is determined visually in the transmitted light of a column of liquid poured into a cylinder 1.2-100 according to GOST 1770.

6.5 Determination of the mass fraction of hydrogen chloride

6.5.1 The method of determination is based on the reaction of neutralization of hydrogen ions with sodium hydroxide:

Methyl orange is used as an indicator.

6.5.2 Equipment, reagents, solutions:

Sodium hydroxide according to GOST 4328, chemically pure, concentration solution c (NaON) = 0.1, prepared according to GOST 25794.1;

Methyl orange (indicator), solution with a mass fraction of 0.1%; an aqueous solution is prepared according to GOST 4919.1;

6.5.3 Conducting analysis

In a pre-weighed flask with a ground stopper with a capacity of 100 and containing 20 of water, 3 analyzed acids are placed and weighed again (the weighing result is recorded to the fourth decimal place). The solution is quantitatively transferred into a volumetric flask with a capacity of 250, rinsed repeatedly with distilled water, poured into a volumetric flask, the volume is adjusted to the mark with water and mixed. Pipette 20% of the resulting hydrochloric acid solution into a 250% conical flask, add 25% of water, 2-3 drops of a methyl orange indicator, and titrate with sodium hydroxide solution until the red color changes to yellow.

6.5.4 Handling results

Mass fraction of hydrogen chloride X, %, is calculated by the formula

where V is the volume of sodium hydroxide solution of concentration exactly c (NaOH) = 0.1, which went for titration, ;

The volume of the analyzed hydrochloric acid solution, taken to perform the analysis, ;

m is the mass of the flask with water, g;

Mass of the flask with water and analyzed acid, g;

0.003646 - mass of hydrogen chloride corresponding to 1 solution of sodium hydroxide, concentration exactly c (NaOH) = 0.1, .

The result of the analysis is taken as the arithmetic mean of the results of two parallel measurements, the allowable discrepancies between which should not exceed 0.3% at a confidence level P = 0.95.

Permissible discrepancies between the results obtained in the two laboratories should not exceed 0.6%. Relative total error of determination at confidence probability P = 0.95.

6.6 Determination of the mass fraction of iron

6.6.1 The mass fraction of iron is determined in hydrochloric acid after diluting the sample without its preliminary neutralization. Neutralization is carried out after the introduction of sulfosalicylic acid, that is, neutralization and the formation of an iron sulfosalicylate complex, which is yellow in a slightly alkaline medium (pH 8.0-11.5), take place simultaneously. The light absorption intensity of the formed complex is measured on a photoelectric colorimeter. Measurement range %.

6.6.2 Equipment, solutions, reagents:

Photoelectric laboratory colorimeter FEK-56M, KFK or other type, providing the specified sensitivity and accuracy;

Stopwatch mechanical any brand;

Flasks 1.2-50, 100, 250 and 1000 according to GOST 1770;

6.6.3 Preparing for analysis

6.6.3.1 Preparation of sulfosalicylic acid solution

10 g of sulfosalicylic acid are transferred into a volumetric flask with a capacity of 100, dissolved, the volume is adjusted to the mark with water, mixed. Weighing results are recorded to the second decimal place.

6.6.3.2 Preparation of calibration solutions and calibration of the photoelectrocolorimeter.

Graduation and determination is carried out according to GOST 10555 by the sulfosalicylic method.

In volumetric flasks with a capacity of 50, 30 of distilled water is introduced, 1 solution of hydrochloric acid, 1.0, is added with a pipette; 2.0; 3.0; 4.0, 6.0 solution of iron with a concentration of 10, 2 solutions of sulfosalicylic acid and 5 solutions of ammonia. After adding each reagent, the solution is stirred. The volume of the solution was made up to the mark with water and mixed. At the same time, a control solution is prepared: 30 water, 1 hydrochloric acid are introduced into a volumetric flask with a capacity of 50, 2 solutions of sulfosalicylic acid are added, and then proceed as described above.

The optical density of the calibration solutions is measured in minutes in cuvettes with a light-absorbing solution layer thickness of 50 mm at a wavelength of 434 nm relative to the control solution. It is allowed to calibrate the instrument using the least squares method.

Based on the results obtained, a calibration graph is built, plotting the mass of iron introduced into the calibration solutions in micrograms along the abscissa axis, and the corresponding values ​​of optical densities on the ordinate axis. The calibration curve is checked once a quarter, as well as when replacing reagents or instruments.

6.6.4 Conducting analysis

A portion of the analyzed hydrochloric acid weighing g is quantitatively transferred into a volumetric flask with a capacity of 250, rinsing the glass several times with water, adjusting the volume of the solution with water to the mark and mixing. Weighing results are recorded to the second decimal place.

A pipette is taken for grades A and B of the highest grade, 25 each, and for grade B of the 1st grade - 2.5 of the prepared solution, transferred to a volumetric flask with a capacity of 50, add 2 solutions of sulfosalicylic acid and mix. Then add 10% ammonia solution, dilute to the mark with water and mix.

Prepare the control solution as described in 6.6.3.2. After a minute, the optical density is measured and, using the calibration graph, the mass of iron in the analyzed solution is found in micrograms.

6.6.5 Handling results

The mass fraction of iron,%, is calculated by the formula

where is the mass of iron in the analyzed solution, found from the calibration curve, μg;

m is the weight of the hydrochloric acid sample taken to perform the analysis, g;

V is the volume of hydrochloric acid solution obtained after diluting the mass of hydrochloric acid, ;

The volume of dilute hydrochloric acid solution taken for analysis, .

The result of the analysis is taken as the arithmetic mean of the results of two parallel measurements, the discrepancies between which should not exceed 0.0005%. The results of the determination are rounded to the fourth decimal place.

Permissible discrepancies between the results obtained in the two laboratories should not exceed 0.0005%.

The absolute total error in determining A, where A is the result of the determination at a confidence level P = 0.95.

6.7 Determination of the mass fraction of residue after ignition

6.7.1 The mass fraction of residue after calcination at 600°C is measured by weight. The determination range is from 0.005 to 0.100%.

6.7.2 Apparatus, solutions and reagents:

Cup quartz type KP with a capacity of 100 according to GOST 19908, platinum or porcelain;

Thermocouple muffle furnace for temperature maintenance;

Calcium chloride, calcined at 250-300°C;

Hourglass for 5 min.

6.7.3 Preparing for analysis

The cup is calcined in a muffle furnace at a temperature for min. Then the cup is placed in a desiccator with calcium chloride and incubated for minutes. The chilled cup is weighed. Weighing results are recorded to the fourth decimal place.

6.7.4 Conducting analysis

85% of the analyzed hydrochloric acid is taken from the cylinder and placed in a quartz cup, 1 drop of sulfuric acid is added and evaporated on a water bath almost to dryness. The cup with the residue is heated on an electric stove until the emission of sulfuric acid vapors ceases. Evaporation of the analyzed acid and decomposition of sulfuric acid can be carried out under an infrared lamp.

After that, the cup with the residue is transferred to a muffle furnace, preheated to , and ignited for min. Transfer the cup to a desiccator, stand min and weigh.

6.7.5 Handling results

The mass fraction of the residue after calcination, %, is calculated by the formula

where is the mass of the cup with the residue after calcination, g;

m is the mass of the empty cup, g;

V is the volume of the hydrochloric acid sample taken for analysis, ;

Density of hydrochloric acid, .

The result of the analysis is taken as the arithmetic mean of the results of two parallel measurements, the allowable discrepancies between which should not exceed 0.0006%. The results of parallel determinations are rounded up to 0.0001%, the result of the determination is 0.001%.

Permissible discrepancies between the results obtained in the two laboratories should not exceed 0.0008%. The absolute total error in determining % at a confidence level P = 0.95.

6.8 Determination of the mass fraction of free chlorine

6.8.1 The method is based on the oxidation reaction of methyl orange with chlorine:

As a result of the oxidation of methyl orange, the color of its solutions becomes less intense. The intensity of the color depends on the order of mixing the solutions, so the analyzed hydrochloric acid is added last with stirring. The method is selective, iron (III) interferes with the determination. Measurement range %.

6.8.2 Apparatus, reagents and solutions:

Photoelectric laboratory colorimeter KFK or other type, providing the specified sensitivity and accuracy;

Arsenic distillation device according to GOST 10485;

Bromine-mercury paper, prepared according to GOST 4517.

6.9.3 Preparing for analysis

6.9.3.1 Preparation of stannous chloride solution

10 g of the reagent are dissolved in 15 hydrochloric acid (if necessary, the conical flask is heated). The solution is transferred to a 100 volumetric flask with a ground stopper, 0.5 g of granulated tin is added, and the volume is adjusted to the mark with water. Weighing results are recorded to the second decimal place.

6.9.3.2 Preparation of 0.001 arsenic solution.

Pipette 1 solution of arsenic, prepared according to GOST 4212, into a volumetric flask with a capacity of 100, bring the volume of the solution with water to the mark and mix. 10% of the resulting solution is taken with a pipette, transferred to a volumetric flask with a capacity of 100, the volume is adjusted to the mark with water and mixed. The solution is used freshly prepared.

6.9.4 Conducting analysis

The determination is carried out according to GOST 10485. To do this, 1.7 (2 g) of the analyzed hydrochloric acid is taken with a pipette, placed in a flask of an instrument for determining arsenic, containing 30 of distilled water. At the same time, a reference solution is prepared: 30% of distilled water is placed in the flask of the device and 2% of the arsenic solution with a concentration of 0.001% is added to the second flask with a pipette.

Then, 7 concentrated hydrochloric acid, 0.5 tin dichloride solution are added to both flasks. 5 g of zinc are added to each flask, and bromine-mercury paper is added to the nozzle. Close quickly with a stopper with a nozzle, mix gently with a rotary motion and leave alone for a minute. After this time, bromine-mercury papers are removed from the devices and the color intensity of the paper is compared with the analyzed solution and the reference solution.

The product complies with the established norm of the standard, if the color intensity of the paper from the analyzed hydrochloric acid solution matches or is less than the intensity of the reference solution.

6.10 Determination of the mass fraction of mercury

6.10.1 Determination of the mass fraction of mercury by the analyzer "Mercury-101".

6.10.1.1 The method is based on measuring the concentration of metallic mercury vapor in the gas phase by the atomic absorption of the resonant radiation of its atoms at a wavelength of 253.7 nm.

Sample preparation consists of boiling the sample in the presence of potassium dichromate to remove chlorine gas. Measuring range from % to %.

6.10.1.2 Equipment, reagents, solutions:

Mercury analyzer type "Mercury-101" (or other device with similar metrological characteristics);

Potassium dichromate according to GOST 4220, solution of concentration 40 (prepared as follows: 4 g of the reagent is dissolved in 100 of water; stored in a flask with a ground stopper; weighing results are recorded to the second decimal place);

The dilution solution is prepared as follows: in a volumetric flask with a capacity of 1000 put 50 nitric acid, 5 potassium dichromate solution and bring to the mark with water;

Tin dichloride, a solution with a mass fraction of 10%, is prepared as follows: 10 g of the reagent is dissolved in a volumetric flask with a capacity of 100 in 25 hydrochloric acid at boiling until the reagent is completely dissolved; after cooling to water, bring the volume to the mark; the freshly prepared solution is cleaned of mercury by blowing with air for at least 5 minutes; use on the day of preparation; weighing results are recorded to the second decimal place;

Mercury (II) nitrate 1-aqueous according to GOST 4520, chemically pure, solution of concentration 0.01 (initial solution of concentration 1 is prepared according to GOST 4212 - solution A; a solution of concentration 0.01 is prepared by appropriate dilution, for which 10 solution A is placed in a volumetric flask with a capacity of 100 and bring the volume with a dilution solution to the mark - solution B of a concentration of 100; good for 3 months; 1 solution B is placed in a volumetric flask with a capacity of 100 and bring the volume with a dilution solution to the mark - solution G of a concentration of 1, good for 7 h; 10 solution G is placed in a volumetric flask with a capacity of 100 and the volume is adjusted with a dilution solution to the mark - a working solution of a concentration of 0.01, valid for 7 h);

6.10.1.3 Safety requirements when working with the device "Mercury-101"

Persons who have studied the design of the device and have been instructed to work with electrical devices operating at a voltage of 1000 V are allowed to work. It is necessary to check the reliability of grounding before work. When repairing or replacing reagents, the instrument must be disconnected from the mains.

6.10.1.4 Preparing for analysis

The device is calibrated according to the passport ( technical description and instructions) supplied with the instrument.

GOST 857-95

INTERSTATESTANDARD

ACIDSALT
SYNTHETIC TECHNICAL

Ttechnical conditions

INTERSTATE COUNCIL
ON STANDARDIZATION, METROLOGY AND CERTIFICATION

Minsk

Foreword

1 DEVELOPED by the Kyiv Research Institute of Synthesis and Ecology (KNII "SINTEKO")

INTRODUCED by the Technical Secretariat of the Interstate Council for Standardization, Metrology and Certification

2 ADOPTED by the Interstate Council for Standardization, Metrology and Certification (Minutes No. 7 of April 26, 1995)

3 Annex B of this standard contains the complete authentic text of International Standard ISO 905-76 Hydrochloric acid for industrial use. Estimation of hydrochloric acid concentration by measuring density"

4 Decision of the Committee Russian Federation on standardization, metrology and certification dated February 27, 1996 No. 117, the interstate standard GOST 857-95 was put into effect directly as state standard Russian Federation since January 1, 1997

6 REVISION. November 2005

GOST 857-95

INTERSTATESTANDARD

ACIDSALT SYNTHETIC TECHNICAL

Ttechnical conditions

Synthetic hydrochloric acid for industrial use.
Specifications

Dintroduction date 1996-07-01

1 area of ​​use

This standard applies to technical synthetic hydrochloric acid obtained by absorption of hydrogen chloride by water, which is formed by the interaction of evaporated, electrolytic chlorine, off-gases from the liquefaction of chlorine with hydrogen.

Technical synthetic hydrochloric acid is used in the chemical, medical, food industry, non-ferrous and ferrous metallurgy.

Formula: HCl.

Molecular weight (according to international atomic masses 1985) - 36.46.

Mandatory requirements for products aimed at ensuring their safety for the life and health of the population and protection environment, are given in table 1, items 6 and 7.

GOST 12.1.005-88 System of labor safety standards. General sanitary and hygienic requirements for the air of the working area

GOST 12.1.044-89 (ISO 4589-84) Occupational safety standards system. Fire and explosion hazard of substances and materials. Nomenclature of indicators and methods for their determination

GOST 12.4.013-85* System of labor safety standards. Goggles. General specifications

* GOST R 12.4.013-97 applies on the territory of the Russian Federation.

GOST 12.4.021-75 System of labor safety standards. Ventilation systems. General requirements

GOST 12.4.103-83 Occupational safety standards system. Special protective clothing, means personal protection legs and arms. Classification

GOST 12.4.121-83 System of labor safety standards. Gas masks industrial filtering. Specifications

GOST 61-75 Acetic acid. Specifications

GOST 199-78 Sodium acetate 3-water. Specifications

GOST 1770-74 Measuring laboratory glassware. Cylinders, beakers, flasks, test tubes. General specifications

GOST 2874-82 ** Drinking water. Hygiene requirements and quality control

** On the territory of the Russian Federation, GOST R 51232-98 applies.

GOST 3118-77 Reagents. Hydrochloric acid. Specifications

GOST 3760-79 Reagents. Ammonia water. Specifications

GOST 4204-77 Reagents. Sulfuric acid. Specifications

GOST 4212-76 Reagents. Preparation of solutions for colorimetric and nephelometric analysis

GOST 4220-75 Reagents. Potassium dichromate. Specifications

GOST 4328-77 Reagents. sodium hydroxide. Specifications

GOST 4461-77 Reagents. Nitric acid. Specifications

GOST 4478-78 Reagents. Sulfosalicylic acid. Specifications

GOST 4517-87 Reagents. Methods for the preparation of auxiliary reagents and solutions used in the analysis

GOST 4520-78 Reagents. Mercury (II) nitrate 1-water. Specifications

GOST 4919.1-77 Reagents and special pure substances. Methods for preparing indicator solutions

GOST 5230-74 Reagents. Mercury oxide is yellow. Specifications

GOST 5456-79 Reagents. Hydroxylamine hydrochloride. Specifications

GOST 6709-72 Distilled water. Specifications

GOST 9557-87 Flat wooden pallet 800×1200 mm in size. Specifications

GOST 10485-75 Reagents. Methods for determining arsenic impurities

GOST 10555-75 Reagents and highly pure substances. Colorimetric methods for determining the content of iron impurities

GOST 10652-73 Reagents. Disodium salt of ethylenediamine-N,N,N′,N′-tetraacetic acid 2-aqueous (trilon B)

GOST 14192-96 Marking of goods

GOST 18300-87 Rectified technical ethyl alcohol. Specifications

GOST 18573-86 Wooden boxes for products of the chemical industry. Specifications

GOST 19433-88 Dangerous goods. Classification and labeling

GOST 19908-90 Crucibles, bowls, glasses, flasks, funnels, test tubes and tips made of transparent quartz glass. General specifications

GOST 20015-88 Chloroform. Specifications

GOST 21650-76 Means of fastening packaged cargoes in overpacks. General requirements

GOST 24104-88* Laboratory scales for general purposes and exemplary. General specifications

GOST 24597-81 Packages of packaged goods. Main parameters and dimensions

GOST 25336-82 Laboratory glassware and equipment. Types, basic parameters and dimensions

GOST 25794.1-83 Reagents. Methods for preparing titrated solutions for acid-base titration

GOST 26319-84 Dangerous goods. Package

GOST 26663-85 Transport packages. Formation using packaging tools. General technical requirements

GOST 29169-91 (ISO 648-77) Laboratory glassware. Pipettes with one mark

GOST 29251-91 (ISO 385-1-84) Laboratory glassware. Burettes. Part 1. General requirements

3 Technical requirements

3.1 Technical synthetic hydrochloric acid must be manufactured in accordance with the requirements of this standard according to the technological regulations approved in the prescribed manner.

3.2 Characteristics

3.2.1 Hydrochloric acid is produced in two grades: A and B.

3.2.2 In terms of physical and chemical parameters, technical synthetic hydrochloric acid must comply with the standards specified in Table 1.

3.3 Marking

3.3.1 Transport marking of barrels and bottles - in accordance with GOST 14192 with the application of the manipulation mark "Sealed packaging".

The marking characterizing the transport hazard of the cargo is according to GOST 19433 (class 8, subclass 8.1, classification number 8172, drawing 8/6 a), UN serial number 1789.

Table 1

Notes

1 The mass fraction of mercury is normalized in the acid obtained from hydrogen and chlorine by mercury electrolysis.

2 It is allowed for the food industry, in agreement with the consumer, the production of acid with a mass fraction of hydrogen chloride of not more than 26%.

3 In acid supplied for pickling metals, the mass fraction of iron and residue after calcination is not standardized.

4 By agreement with the consumer, the mass fraction of hydrogen chloride of at least 30% is allowed in both grades of acid.

3.3.2 A label made of plywood or thick cardboard, protected by an acid-resistant and moisture-proof shell, is attached to each barrel or bottle, on which the data characterizing the packaged product are applied:

Name of the enterprise and (or) its trademark;

Product name, brand, grade;

The designation of this standard;

Gross and net weight;

The number of the barrel or bottle and the total number of them in the lot.

3.3.3 Signs and inscriptions on tanks and containers are applied in accordance with the requirements of the "Rules for the Transportation of Dangerous Goods" (Part 2, Section 41, 1987, Moscow).

3.4 Package

3.4.1 Technical synthetic hydrochloric acid is poured into special gummed tanks of the sender or recipient, rubberized containers, polyethylene barrels with a capacity of 50 dm 3 and glass bottles with a capacity of 20 dm 3 in accordance with the current regulatory documentation.

Glass bottles are packed in boxes of type V-1, number 3-2 according to GOST 18573. Packaging must comply with GOST 26319.

3.4.2 It is allowed to pour the product into tanks and containers with hydrochloric acid residue, if the analysis of the residue confirms that its quality complies with the requirements of this standard. Otherwise, the residual hydrochloric acid is removed and the tank or container is washed.

Barrels and bottles must be dry and clean.

3.4.3 Filling hatches of tanks, containers and drum plugs should be sealed with rubber or polyethylene gaskets, both when sent to consumers (filled with acid), and when returned to the supplier of empty containers.

Bottle necks sealed with ground glass stoppers or screw caps should be wrapped with plastic wrap and tied with twine.

3.4.4 The level (degree) of filling of tanks, containers, barrels and bottles is calculated taking into account the maximum use of the carrying capacity (capacity) and volumetric expansion of the product with a possible temperature drop along the route.

4 Safety requirements

4.1 Commercial grade synthetic hydrochloric acid is a caustic liquid that is chemically stable.

In the air, it "smokes" as a result of the release of hydrogen chloride and the attraction of air moisture by it with the formation of acid fog.

Metals located in the voltage series to the left of hydrogen (Al, Zn, Fe, Co, Ni, Pb, etc.) displace it from hydrochloric acid, which can lead to the formation of explosive hydrogen-air mixtures.

Safety measures - exclusion of contact of hydrochloric acid with these metals due to anti-corrosion coatings, purging with nitrogen and checking the gas phase from equipment and pipelines for explosiveness before hot work.

4.2 According to GOST 12.1.044, the product belongs to non-combustible substances.

4.3 Hydrochloric acid mist irritates the upper respiratory tract and mucous membranes of the eyes. Contact with skin causes burns.

4.4 According to GOST 12.1.005, the maximum permissible concentration (MPC) of hydrochloric acid vapors in the air of the working area is 5 mg/m 3, hazard class is 2 (highly hazardous substances);

MPC of chlorine in the air of the working area - 1 mg / m 3, hazard class - 2 (highly hazardous substances).

Chlorine and hydrochloric acid have a highly directed mechanism of action. When working with them, special protection of the skin and eyes is necessary.

Determination of hydrogen chloride, chlorine - according to the current regulatory documentation.

Sampling points should be agreed with local authorities sanitary and epidemiological services. Assessment of the state of the air environment with the simultaneous presence of chlorine and hydrogen chloride - according to GOST 12.1.005.

4.5 Technological processes for the production and use of hydrochloric acid and the production equipment used must comply with the requirements of sanitary rules No. 1042-73.

Production facilities must be equipped with ventilation in accordance with GOST 12.4.021 and SNiP 2.04.05-91 and a water supply that meets the requirements of GOST 2874.

4.6 All work with hydrochloric acid should be carried out in overalls of type K50 in accordance with GOST 12.4.103 and in goggles of type G in accordance with GOST 12.4.013.

All workers must be provided with industrial filtering gas masks of grade B (PPE FGP, FG-130) in accordance with GOST 12.4.121.

4.7 In the event of a spill, hydrochloric acid is washed off floor surfaces and equipment with plenty of water or an alkaline solution. Acid wastewater must be neutralized at local treatment plants before it enters the general sewerage system.

4.8 The fire is extinguished with the help of sprayed water and air-mechanical foam.

4.9 Substandard product is neutralized with an alkali solution. Gas emissions are captured and neutralized.

5 Acceptance

5.1 Technical synthetic hydrochloric acid must be presented for acceptance in batches.

A batch is any amount of hydrochloric acid, homogeneous in its qualitative composition, issued by one quality document.

The quality document must contain the following data:

Name and (or) trademark of the manufacturer;

Name of the product and its brand, grade, standard designation;

Batch number, date of manufacture;

Tank number, number of containers, barrels, bottles;

Net weight;

Classification code according to GOST 19433;

The results of the analysis carried out or confirmation of the quality compliance with the requirements of this standard.

5.2 To check the quality of hydrochloric acid, acceptance and periodic tests are carried out.

5.3 The manufacturer determines the mass fraction of arsenic periodically once a quarter.

5.4 During acceptance tests at the manufacturer, samples are taken from a commodity tank intended for filling containers.

To check the quality of hydrochloric acid, samples are taken from the consumer:

From each tank and container;

From 10% of barrels, bottles, but not less than three in batches of less than 10 barrels, bottles.

5.5 If unsatisfactory analysis results are obtained for at least one of the indicators, a reanalysis is carried out on a double sample or a newly selected sample from a tank, container, barrels, bottles.

The results of the reanalysis apply to the entire lot.

6 Methods of analysis

6.1 Point samples from the tank and tank are taken by slowly immersing a sampler of any design, made of acid-resistant materials, to the bottom of the tank, tank.

Point samples from barrels, bottles and containers are taken using a glass or polyethylene tube with a diameter of 10 - 15 mm with a drawn end.

A pooled sample is obtained by mixing equal volumes of incremental samples.

6.2 From a thoroughly mixed pooled sample, a sample is taken for analysis with a volume of at least 1 dm 3, which is placed in a dry, clean bottle with a ground stopper or a polyethylene jar with a screw cap. A label is stuck on a bottle or plastic jar indicating:

Name of manufacturer and product;

Designations of this standard, brand and grade;

Dates and locations of sampling;

Batch numbers and dates of manufacture;

Name of the person who took the sample.

6.3 General instructions for the analysis

During the analysis, the air temperature should be (20 ± 5) °C.

When weighing, general-purpose laboratory scales in accordance with GOST 24104 accuracy classes 2 and 4 should be used with the largest weighing limits of 200 and 500 g.

It is allowed to use imported utensils according to the accuracy class and reagents in quality not lower than domestic ones.

It is allowed to determine the density of hydrochloric acid according to Appendix B.

6.4 Appearance definition

The appearance is determined visually in the transmitted light of a column of liquid poured into a cylinder 1.2-100 according to GOST 1770.

6.5 Determination of the mass fraction of hydrogen chloride

6.5.1 The method of determination is based on the reaction of neutralization of hydrogen ions with sodium hydroxide:

H + + OH - = H 2 O. (1)

Methyl orange is used as an indicator.

6.5.2 Equipment, reagents, solutions:

Burette 1, 2, 3-25-0.1 according to GOST 29251;

Flask Kn-1,2-100, 250-1 according to GOST 25336;

Flask 2-250, 1000 according to GOST 1770;

Pipette 2-20 according to GOST 29169;

Cylinder 1.2-25 according to GOST 1770;

Sodium hydroxide according to GOST 4328, chemically pure, concentration solution c(NaON) = 0.1 mol / dm 3, prepared according to GOST 25794.1;

Methyl orange (indicator), solution with a mass fraction of 0.1%; an aqueous solution is prepared according to GOST 4919.1;

Distilled water according to GOST 6709 and not containing carbon dioxide is prepared according to GOST 4517.

6.5.3 Conducting analysis

In a pre-weighed flask with a ground stopper with a capacity of 100 cm 3 and containing 20 cm 3 of water, 3 cm 3 of the analyzed acid are placed and weighed again (the weighing result is recorded to the fourth decimal place). The solution is quantitatively transferred into a volumetric flask with a capacity of 250 cm 3, repeatedly rinsed with distilled water, poured into a volumetric flask, the volume is adjusted to the mark with water and mixed. Pipette 20 cm 3 of the resulting hydrochloric acid solution into a conical flask with a capacity of 250 cm 3, add 25 cm 3 of water, 2-3 drops of a methyl orange indicator and titrate with sodium hydroxide solution until the red color changes to yellow.

6.5.4 Handling results

Mass fraction of hydrogen chloride X, %, calculated by the formula

where V- volume of sodium hydroxide solution concentration exactly c(NaOH) \u003d 0.1 mol / dm 3, used for titration, cm 3;

V 1 - the volume of the solution of the analyzed hydrochloric acid, taken to perform the analysis, cm 3 ;

m- mass of the flask with water, g;

m 1 - mass of the flask with water and analyzed acid, g;

0.003646 - mass of hydrogen chloride, corresponding to 1 cm 3 sodium hydroxide solution, concentration exactly c(NaOH) \u003d 0.1 mol / dm 3, g / cm 3.

The result of the analysis is taken as the arithmetic mean of the results of two parallel measurements, the allowable discrepancies between which should not exceed 0.3% with a confidence level P = 0,95.

Permissible discrepancies between the results obtained in the two laboratories should not exceed 0.6%. Relative total error of determination ±2% at confidence level P = 0,95.

6.6 Determination of the mass fraction of iron

6.6.1 The mass fraction of iron is determined in hydrochloric acid after diluting the sample without its preliminary neutralization. Neutralization is carried out after the introduction of sulfosalicylic acid, that is, neutralization and the formation of a sulfosalicylate complex of iron 3, colored yellow in a slightly alkaline medium (pH 8.0 - 11.5), take place simultaneously. The light absorption intensity of the formed complex is measured on a photoelectric colorimeter. Measuring range 5 10 -4 - 2.0 10 -2%.

6.6.2 Equipment, solutions, reagents:

Photoelectric laboratory colorimeter FEK-56M, KFK or other type, providing the specified sensitivity and accuracy;

Stopwatch mechanical any brand;

Cup SZ-14/8 according to GOST 25336;

Flasks 1.2-50, 100, 250 and 1000 cm 3 according to GOST 1770;

Pipettes 1, 2, 5, 7-1, 25, 2, 5, 10 according to GOST 29169;

Hydrochloric acid according to GOST 3118, chemically pure, aqueous solution (1:1);

Aqueous ammonia according to GOST 3760, analytical grade, solution with a mass fraction of 25%;

Sulfosalicylic acid according to GOST 4478, analytical grade, concentration solution 100 g/dm 3 ;

Iron-ammonium alum in accordance with the current regulatory documentation;

A solution of iron with a concentration of 1 mg/cm 3 is prepared according to GOST 4212, a freshly prepared solution of a concentration of 10 μg/cm 3 is prepared by dilution;

6.6.3 Preparing for analysis

6.6.3.1 Preparation of sulfosalicylic acid solution

10 g of sulfosalicylic acid are transferred into a volumetric flask with a capacity of 100 cm 3, dissolved, the volume is adjusted to the mark with water, mixed. Weighing results are recorded to the second decimal place.

6.6.3.2 Preparation of calibration solutions and calibration of the photoelectrocolorimeter.

Graduation and determination is carried out according to GOST 10555 by the sulfosalicylic method.

30 cm 3 of distilled water are introduced into volumetric flasks with a capacity of 50 cm 3, 1 cm 3 of hydrochloric acid solution, 1.0, is added with a pipette; 2.0; 3.0; 4.0; 6.0 cm 3 iron solution with a concentration of 10 μg/cm 3 , 2 cm 3 sulfosalicylic acid solution and 5 cm 3 ammonia solution. After adding each reagent, the solution is stirred. The volume of the solution was made up to the mark with water and mixed. At the same time, a control solution is prepared: 30 cm 3 of water, 1 cm 3 of hydrochloric acid are introduced into a volumetric flask with a capacity of 50 cm 3, 2 cm 3 of a solution of sulfosalicylic acid are added, and then proceed as described above.

The optical density of the calibration solutions is measured after (10 ± 1) min in cuvettes with a light-absorbing solution layer thickness of 50 mm at a wavelength of 434 nm relative to the control solution. It is allowed to calibrate the instrument using the least squares method.

Based on the results obtained, a calibration graph is built, plotting the mass of iron introduced into the calibration solutions in micrograms along the abscissa axis, and the corresponding values ​​of optical densities on the ordinate axis. The calibration curve is checked once a quarter, as well as when replacing reagents or instruments.

6.6.4 Conducting analysis

A portion of the analyzed hydrochloric acid weighing (20 ± 1) g is quantitatively transferred into a volumetric flask with a capacity of 250 cm 3, rinsing the glass several times with water, bringing the volume of the solution to the mark with water and mixing. Weighing results are recorded to the second decimal place.

For grades A and B of the highest grade, 25 cm 3 are taken with a pipette, and for grade B of the 1st grade - 2.5 cm 3 of the prepared solution, transferred to a volumetric flask with a capacity of 50 cm 3, add 2 cm 3 of a solution of sulfosalicylic acid and mix. Then add 10 cm 3 of ammonia solution, bring the volume to the mark with water and mix.

Prepare the control solution as described in 6.6.3.2. After (10 ± 1) min, the optical density is measured and, using the calibration curve, the mass of iron in the analyzed solution is found in micrograms.

6.6.5 Handling results

Mass fraction of iron X 1 , %, calculated by the formula

where m 1 - mass of iron in the analyzed solution, found according to the calibration curve, μg;

m- weight of the sample of hydrochloric acid, taken to perform the analysis, g;

V- the volume of hydrochloric acid solution obtained after diluting the mass of hydrochloric acid, cm 3;

V 1 - volume of dilute hydrochloric acid solution taken for analysis, cm 3 .

The result of the analysis is taken as the arithmetic mean of the results of two parallel measurements, the discrepancies between which should not exceed 0.0005%. The results of the determination are rounded to the fourth decimal place.

Absolute total error of determination ±0.2A, where A is the result of determination at a confidence level P = 0,95.

( Amendment )

6.7 Determination of the mass fraction of the residue after calcination

6.7.1 The mass fraction of the residue after calcination at 600 °C is measured by weight. The determination range is from 0.005% to 0.100%.

6.7.2 Apparatus, solutions and reagents:

Cylinder 2-100 according to GOST 1770;

Cup quartz type KP with a capacity of 100 cm 3 according to GOST 19908, platinum or porcelain;

Desiccator 2-190 mm, 250 mm according to GOST 25336;

A muffle furnace with a thermocouple that maintains a temperature of (600 ± 10) °С;

Sulfuric acid according to GOST 4204, chemically pure;

Calcium chloride, calcined at 250 - 300 ° C;

Hourglass for 5 min.

6.7.3 Preparing for analysis

The cup is calcined in a muffle furnace at a temperature of (600 ± 10) °C for (5 ± 1) min. Then the cup is placed in a desiccator with calcium chloride and incubated for (30 ± 5) min. The chilled cup is weighed. Weighing results are recorded to the fourth decimal place.

6.7.4 Conducting analysis

85 cm 3 of hydrochloric acid to be analyzed is taken with a cylinder and placed in a quartz cup, 1 drop of sulfuric acid is added and the mixture is evaporated almost to dryness on a water bath. The cup with the residue is heated on an electric stove until the emission of sulfuric acid vapors ceases. Evaporation of the analyzed acid and decomposition of sulfuric acid can be carried out under an infrared lamp.

After that, the cup with the residue is transferred to a muffle furnace preheated to (600 ± 10) °C and calcined for (5 ± 1) min. Transfer the dish to a desiccator, stand for (30 ± 5) min and weigh.

6.7.5 Handling results

Mass fraction of residue after calcination X 2 , %, calculated by the formula

where m 1 - mass of the cup with the residue after calcination, g;

m- weight of the empty cup, g;

V- the volume of the hydrochloric acid sample taken for analysis, cm 3;

The result of the analysis is taken as the arithmetic mean of the results of two parallel measurements, the allowable discrepancies between which should not exceed 0.0006%. The results of parallel determinations are rounded up to 0.0001%, the result of the determination is 0.001%.

Permissible discrepancies between the results obtained in the two laboratories should not exceed 0.0008%. Absolute total error of determination ±0.0005% at confidence level P = 0,95.

6.8 Determination of the mass fraction of free chlorine

6.8.1 The method is based on the oxidation reaction of methyl orange with chlorine:

As a result of the oxidation of methyl orange, the color of its solutions becomes less intense. The intensity of the color depends on the order of mixing the solutions, so the analyzed hydrochloric acid is added last with stirring. The method is selective, iron (III) interferes with the determination. Measuring range 5 10 -4 - 8 10 -3%.

6.8.2 Apparatus, reagents and solutions:

Photoelectric laboratory colorimeter KFK or other type, providing the specified sensitivity and accuracy;

Volumetric flasks 2-25, 1000 according to GOST 1770;

Pipettes 1.5-1.2 according to GOST 29169;

Hydrochloric acid according to GOST 3118, chemically pure, solution (1:2);

Methyl orange (indicator), a solution with a concentration of 0.1 g / dm 3, is prepared as follows: 0.1 g of methyl orange is transferred into a volumetric flask with a capacity of 1000 cm 3, the volume of the solution is adjusted to the mark with water and mixed. Weighing results are recorded to the second decimal place.

6.8.3 Preparation of calibration solutions and calibration of the photoelectric colorimeter

15 cm 3 of water are introduced into volumetric flasks with a capacity of 25 cm 3, 2.0 is added with a pipette; 1.6; 1.2; 0.8; 0.4 cm 3 solution of methyl orange, which corresponds to 0; ten; 20; thirty; 40 μg of chlorine, add 1 cm 3 of hydrochloric acid solution, dilute the volume of the solution with water to the mark and mix. The optical density of the obtained solutions is measured on a photoelectric colorimeter at a thickness of the light-absorbing solution layer of 10 mm and at a wavelength of 490 - 505 nm. Reference solution - distilled water.

Based on the data obtained, a calibration graph is built, plotting the mass of chlorine in micrograms on the abscissa axis, and the corresponding value of optical densities on the ordinate axis.

The calibration curve is checked once a quarter, as well as when replacing reagents or instruments.

It is allowed to calibrate the instrument using the least squares method.

6.8.4 Conducting analysis

15 cm 3 of distilled water are placed in a volumetric flask with a capacity of 25 cm 3, stirring vigorously, 2 cm 3 of a solution of methyl orange, (0.5 - 2) cm 3 of the analyzed hydrochloric acid are injected with a pipette, the volume of the solution is adjusted to the mark with water and mixed. The optical density of the resulting solution is measured on a photoelectric colorimeter at a thickness of the light-absorbing layer of the solution of 10 mm and a wavelength of 490 - 505 nm. Reference solution - distilled water.

The mass of chlorine in micrograms in acid is found according to the calibration curve.

6.8.5 Handling results

Mass fraction of free chlorine X 3 , %, calculated by the formula

where m is the mass of chlorine in the analyzed hydrochloric acid, found from the calibration curve, μg;

V- the volume of hydrochloric acid taken to perform the analysis, cm 3;

ρ is the density of the analyzed hydrochloric acid, g/cm 3 .

The result of the analysis is taken as the arithmetic mean of the results of three parallel measurements, the discrepancies between which should not exceed 0.0003%. The results of the determination are rounded up to 0.0001%.

Permissible discrepancies between the results obtained in the two laboratories should not exceed 0.0005%.

The absolute total error of the determination is in the range of ±0.2A, where A is the result of the determination at a confidence level P = 0,95.

6.9 Determination of the mass fraction of arsenic

6.9.1 The method is based on the distillation of arsenic compounds in the form of arsenic hydrogen and its further interaction with mercury bromide to form an orange compound, the color intensity of which is compared with the color intensity of a standard containing 0.002 and 0.004 mg of arsenic. The sensitivity of the method is 0.0001%.

6.9.2 Equipment, solutions, reagents:

Flasks Kn-2-100, 250 according to GOST 25336;

Pipettes 1.5-2.10 according to GOST 29169;

Volumetric flasks 2.2-100, 1000 according to GOST 1770;

Arsenic distillation device according to GOST 10485;

Cylinder 1.2-100 according to GOST 1770;

Hydrochloric acid according to GOST 3118, chemically pure, solution with a mass fraction of 15%;

Tin dichloride according to the current regulatory documentation - a solution with a mass fraction of 10%;

Tin granulated in accordance with the current regulatory documentation;

Zinc granulated in accordance with the current regulatory documentation;

A solution of arsenic mass concentration of 1 mg/cm 3 prepared according to GOST 4212;

Distilled water according to GOST 6709;

Bromine-mercury paper, prepared according to GOST 4517.

6.9.3 Preparing for analysis

6.9.3.1 Preparation of stannous chloride solution

10 g of the reagent are dissolved in 15 cm 3 of hydrochloric acid (if necessary, the conical flask is heated). The solution is transferred into a volumetric flask with a ground stopper with a capacity of 100 cm 3, add 0.5 g of granulated tin, bring the volume to the mark with water. Weighing results are recorded to the second decimal place.

6.9.3.2 Preparation of 0.001 mg/cm 3 arsenic solution

Pipette 1 cm 3 of an arsenic solution prepared according to GOST 4212 into a volumetric flask with a capacity of 100 cm 3, bring the volume of the solution to the mark with water and mix. 10 cm 3 of the resulting solution is taken with a pipette, transferred to a volumetric flask with a capacity of 100 cm 3, the volume is adjusted to the mark with water and mixed. The solution is used freshly prepared.

6.9.4 Conducting analysis

The determination is carried out according to GOST 10485. To do this, 1.7 cm 3 (2 g) of the analyzed hydrochloric acid are taken with a pipette, placed in a flask of an instrument for the determination of arsenic containing 30 cm 3 of distilled water. At the same time, a reference solution is prepared: 30 cm 3 of distilled water are placed in the flask of the device and 2 cm 3 are added to one flask, and 4 cm 3 of an arsenic solution with a concentration of 0.001 mg / cm 3 are added to the second flask.

Then, 7 cm 3 of concentrated hydrochloric acid, 0.5 cm 3 of a solution of tin dichloride are added to both flasks. 5 g of zinc are added to each flask, and bromine-mercury paper is added to the nozzle. Close quickly with a stopper with a nozzle, gently mix with a rotary motion and leave alone for (90 ± 10) min. After this time, bromine-mercury papers are removed from the devices and the color intensity of the paper is compared with the analyzed solution and the reference solution.

The product complies with the established norm of the standard, if the color intensity of the paper from the analyzed hydrochloric acid solution matches or is less than the intensity of the reference solution.

6.10 Determination of the mass fraction of mercury

6.10.1 Determination of the mass fraction of mercury by the analyzer "Mercury-101"

6.10.1.1 The method is based on measuring the concentration of metallic mercury vapor in the gas phase by the atomic absorption of the resonant radiation of its atoms at a wavelength of 253.7 nm.

Sample preparation consists of boiling the sample in the presence of potassium dichromate to remove chlorine gas. Measuring range from 0.5% to 5 10 -4%.

6.10.1.2 Equipment, reagents, solutions:

Mercury analyzer type "Mercury-101" (or other device with similar metrological characteristics);

Flasks 2-100, 1000 according to GOST 1770;

Pipettes 1, 2, 6, 7-1, 2, 5, 10 according to GOST 29169;

Cylinder 3-100 according to GOST 1770;

Flasks Kn-1.50 according to GOST 25336;

Potassium dichromate according to GOST 4220, a solution with a concentration of 40 g / dm 3 (prepared as follows: 4 g of the reagent is dissolved in 100 cm 3 of water; stored in a flask with a ground stopper; weighing results are recorded to the second decimal place);

The dilution solution is prepared as follows: 50 cm 3 of nitric acid, 5 cm 3 of potassium bichromate solution are placed in a volumetric flask with a capacity of 1000 cm 3 and brought to the mark with water;

Tin dichloride, a solution with a mass fraction of 10%, is prepared as follows: 10 g of the reagent is dissolved in a volumetric flask with a capacity of 100 cm 3 in 25 cm 3 of hydrochloric acid at boiling until the reagent is completely dissolved; after cooling to (20 ± 5) °С, the volume is adjusted to the mark with water; the freshly prepared solution is cleaned of mercury by blowing with air for at least 5 minutes; use on the day of preparation; weighing results are recorded to the second decimal place;

Mercury (II) nitrate 1-aqueous according to GOST 4520, chemically pure, solution of concentration 0.01 μg / cm 3 (initial solution of concentration 1 mg / cm 3 is prepared according to GOST 4212 - solution A; a solution of concentration 0 is prepared by appropriate dilution, 01 μg / cm 3, for which 10 cm 3 of solution A is placed in a volumetric flask with a capacity of 100 cm 3 and the volume is adjusted with a dilution solution to the mark - solution B with a concentration of 100 μg / cm 3; good for 3 months; 1 cm 3 of solution B is placed into a volumetric flask with a capacity of 100 cm 3 and bring the volume with a dilution solution to the mark - solution D with a concentration of 1 μg / cm 3, valid for 7 hours; 10 cm 3 of solution D is placed in a volumetric flask with a capacity of 100 cm 3 and the volume is adjusted with a dilution solution to the mark - working solution with a concentration of 0.01 µg/cm 3 , valid for 7 hours);

Distilled water according to GOST 6709.

6.10.1.3 Safety requirements when working with the device "Mercury-101"

Persons who have studied the design of the device and have been instructed to work with electrical devices operating at a voltage of 1000 V are allowed to work. It is necessary to check the reliability of grounding before work. When repairing or replacing reagents, the instrument must be disconnected from the mains.

6.10.1.4 Preparing for analysis

The device is calibrated according to the passport (technical description and instructions) attached to the device.

6.10.1.5 Sample preparation

In pre-weighed two conical flasks containing (20 ± 1) cm 3 of distilled water, place 10 g of the analyzed hydrochloric acid. Weighing results are recorded to the second decimal place. Then, up to 1 cm 3 of a potassium dichromate solution is added to the flasks and the samples are boiled for 5 minutes, provided that the yellow color of the potassium bichromate is preserved. Otherwise, add a solution of potassium dichromate in portions of 0.5 cm 3 . After cooling, the solution was quantitatively transferred into a volumetric flask with a capacity of 100 cm 3, adjusted to the mark with water (solution E).

At the same time, a control experiment is carried out under the same conditions, for which 20 cm 3 of water and the same amount of potassium bichromate are introduced into the same conical flask, which was used in the preparation of the sample. Boil 5 min. After cooling, the solution is transferred to a 100 cm 3 volumetric flask (solution E).

2 cm 3 of solution D are placed in a volumetric flask with a capacity of 100 cm 3 and the volume is adjusted to the mark with a dilution solution (solution D 1). Solution E is also diluted to give solution E 1 .

6.10.1.6 Perform analysis.

Solutions D 1 and E 1 are placed sequentially, starting with the control, into the analyzer reactor and the measurement is carried out according to the instructions for the device.

The analysis result is taken as the arithmetic mean of the analyzer readings for two parallel samples (a), the discrepancy between which does not exceed ±(10 + 0.05), where is the arithmetic mean of the analyzer readings for two parallel samples.

6.10.1.7 Handling results

Mass fraction of mercury X 4 , %, calculated by the formula

where is the arithmetic mean of the analyzer readings when measuring two parallel samples;

b- analyzer readings during control solution measurement;

1/1000 - division value of the analyzer, mcg;

m is the mass of the analyzed acid sample, g (10 g).

The measurement results are rounded up to 1 · 10 -5%.

Relative total measurement error ±10% at confidence level P = 0,95.

6.10.2 Determination of the mass fraction of mercury with dithizone

6.10.2.1 Apparatus, solutions and reagents:

Water ammonia according to GOST 3760, diluted 1:10;

Acetic acid according to GOST 61, chemically pure, concentration solution c(CH 3 COOH) \u003d 1 mol / dm 3;

Acetic sodium according to GOST 199, analytical grade, concentration solution c(CH 3 COONa) = = 1 mol / dm 3;

Acetate buffer solution is prepared as follows: mix equal volumes of sodium acetate solution and acetic acid solution;

Hydroxylamine hydrochloric acid according to GOST 5456, analytical grade, aqueous solution with a mass fraction of 10%, freshly prepared;

Nitric acid according to GOST 4461, chemically pure;

Sulfuric acid according to GOST 4204, concentration solution c(1/2 H 2 SO 4) \u003d 0.1 mol / dm 3;

Disodium salt of ethylenediamine-N,N,N′,N′-tetraacetic acid 2-aqueous (trilon B) according to GOST 10652, concentration solution c(trilon B) \u003d 0.1 mol / dm 3;

Chloroform according to GOST 20015;

Dithizone (diphenylthiocarbazone) in accordance with the current regulatory documentation, analytical grade (a solution of dithizone in chloroform is prepared as follows: 0.2 g of dithizone is dissolved in 50 cm 3 of chloroform, transferred to a separating funnel with a capacity of 250 cm 3, 100 cm 3 of ammonia solution (1:10) is added and shaken; the ammonia solution is separated and transferred to another separating funnel; the operation is repeated three times; then the ammonia solution is acidified with sulfuric acid to pH 3-4 and the dithizone is extracted three times with chloroform in portions of 20 cm 3; the chloroform extract is washed three times and diluted to 100 cm 3 with chloroform (solution A); save the solution dithizone under a layer of sulfuric acid solution in a dark, cool place; before use, solution A is diluted with chloroform so that the optical density of the solution, measured on a FEK-56 photoelectrocolorimeter or another brand device, at a wavelength of 580 - 587 nm (light filter 8 in a cuvette with a thickness absorbing light layer solution 0.5 cm) would be 0.75 (solution B);

Mercury oxide yellow according to GOST 5230;

An exemplary solution of mercury is prepared according to GOST 4212 or as follows: 0.1079 g of mercury oxide is dissolved by heating slightly in 2 - 3 cm 3 of concentrated nitric acid and adjusted to 100 cm 3 with water; 1 cm 3 of the resulting solution contains 1 mg of mercury; dilution prepare a solution containing 0.010 mg of mercury in 1 cm 3; Weighing results are recorded to the fourth decimal place:

Universal indicator paper;

Distilled water according to GOST 6709;

Photoelectrocolorimeter FEK-56 or a similar device with a given accuracy and sensitivity;

Funnel VD1-250 according to GOST 25336;

Glass 1.2-100 according to GOST 25336.

6.10.2.2 Building a calibration curve

In five separating funnels with a capacity of 250 cm 3 add 50 cm 3 of water, 1, 2, 3, 4 and 5 cm 3 of a diluted standard solution of mercury, which corresponds to 0.010; 0.020; 0.030; 0.040 and 0.050 mg of mercury, 5 cm 3 of a solution of Trilon B, 10 cm 3 of a buffer solution, stirred for 1 min, 5 cm 3 of chloroform were added, stirred again for 1 min, and after settling, the chloroform was discarded. Then add 10 cm 3 of solution B (ditizone) and shake for 2 minutes. In parallel, prepare a control solution containing all reagents except mercury under the same conditions.

After phase separation, the chloroform layer is separated and the optical density is measured on a photoelectric colorimeter in a cuvette with a light-absorbing solution layer thickness of 0.5 cm with a light filter 8. Reference solution - chloroform.

A calibration graph is built in the coordinates "optical density - mercury concentration, mg".

6.10.2.3 Conducting analysis

5 cm 3 of the analyzed acid is placed in a beaker with a capacity of 100 cm 3 and water is added to 30 cm 3 . The contents of the beaker, after cooling, are slowly neutralized with ammonia solution to pH 4 according to indicator paper, water is added to 50 cm 3, 5 cm 3 of Trilon B solution, 10 cm 3 of buffer solution, 1 - 3 cm 3 of hydroxylamine solution. After 10 minutes, the solution is transferred to a separating funnel with a capacity of 250 cm 3 , 5 cm 3 of chloroform are added, stirred, and after settling, the chloroform layer is discarded.

To check the purity of the reagents, a control experiment is carried out, for which 50 cm 3 of water are placed in a separating funnel with a capacity of 250 cm 3, 5 cm 3 of Trilon B, 10 cm 3 of a buffer solution, 1 - 3 cm 3 of a hydroxylamine solution are introduced. After 10 min, 5 cm 3 of chloroform are added, stirred for 1 min, and after settling, the chloroform layer is discarded. Extraction and determination of mercury is carried out as described in 6.10.2.2.

6.10.2.4 Handling results

Mass fraction X 6,%, calculated by the formula

where m 1 - mass of mercury in the analyzed sample, found according to the calibration curve, mg;

m 2 - mass of mercury found in the control experiment, mg;

V- the volume of hydrochloric acid taken for analysis, cm 3;

ρ is the density of hydrochloric acid, g/cm 3 .

The result of the analysis is taken as the arithmetic mean of the results of two parallel measurements, the allowable discrepancies between which should not exceed 3 × 10 -5%.

In case of disagreement in assessing the quality of products, the mass fraction of mercury is determined by a chemical method.

7 Transport and storage

7.1 Technical synthetic hydrochloric acid in accordance with the rules for the transport of dangerous goods is transported:

In bulk in railway tanks (“Regulations for the Transport of Dangerous Goods No. 340”, part 2, section 41);

Packed in barrels and bottles in boxes - by rail in covered wagons by car shipments (“Rules for the Transportation of Dangerous Goods No. 340”, part 2, section 42);

Packed in containers, barrels, bottles - by road and water transport.

7.2 When shipped in packages, barrels and bottles are formed on flat wooden pallets in accordance with GOST 9557-87 in accordance with the requirements of GOST 21650, GOST 24597 and GOST 26663.

The weight of the package must not exceed the carrying capacity of the pallet.

In a railway car, the packages are installed so that the capacity (carrying capacity) of the car is fully used.

7.3 Technical synthetic hydrochloric acid is stored in sealed containers of the manufacturer and consumer, made of materials resistant to hydrochloric acid.

The shelf life of the product is unlimited.

METHODOLOGY
measurement of the mass concentration of hydrogen chloride in the air industrial premises

A.1Purpose and scope

This technique is designed to measure the mass concentration of hydrogen chloride in the air of industrial premises.

The technique was performed in accordance with the current regulatory documentation.

Measurement range - (0.6 - 20) mg / m 3.

The duration of the analysis is 30 minutes.

A.2Method of measurement

To measure the mass concentration of hydrogen chloride in the air, a photocolorimetric method of analysis is used, based on the interaction of chloride with mercury thiocyanate and the formation of a colored iron complex with thiocyanate.

Photometry conditions:

Wavelength - (480 ± 5) nm;

The thickness of the light-absorbing layer is 10 mm.

A.3Crockery, instruments and reagents:

General purpose laboratory scales of accuracy classes 2 and 4 according to GOST 24104 with maximum weighing limits of 200 and 500 g;

Photoelectric colorimeter of the KFK type or another type, providing the specified sensitivity and accuracy;

Flasks 2-100 (500, 1000) according to GOST 1770;

Pipettes 4.5-2-1 (2); 6.7-2-5 (10) according to GOST 29169;

Test tubes graduated P-1-15-0.1 according to GOST 1770;

Flat-bottom colorimetric test tubes made of colorless glass, 120 mm high, with an inner diameter of 15 mm;

Absorption devices with a porous plate No. 2;

Nitric acid according to GOST 4461, chemically pure;

Iron-ammonium alum in accordance with the current regulatory documentation, solution of mass concentration 61 g/dm 3 ;

Mercury thiocyanate, solution in ethyl alcohol, mass fraction 0.25%;

A solution of chlorides with an exact mass concentration of 1 mg / cm 3, prepared according to GOST 4212, a solution of chlorides with an exact mass concentration of 10 μg / cm 3 is prepared by dilution;

Rectified technical ethyl alcohol in accordance with GOST 18300, the highest grade;

Distilled water according to GOST 6709.

A.4Preparing to take measurements

A4.1 Preparation of a solution of iron ammonium alum

A solution of iron ammonium alum with a mass concentration of 61 g / dm 3 is prepared as follows: 61.00 g of iron ammonium alum is transferred into a flask, 100 cm 3 of water and 310 cm 3 of nitric acid are added, dissolved and filtered through a funnel with a porous glass plate No. 4 into a volumetric flask 2-1000-2. The solution in the flask was made up to the mark with water and mixed.

A.4.2 Air sampling

Air at a speed of 1 dm 3 /min is passed for (15 ± 0.3) minutes through two series-connected absorption devices with a porous plate containing 10 cm 3 of distilled water. The absorption solutions are quantitatively transferred into graduated test tubes, the volume is adjusted to 15 cm 3 with water and mixed.

A.4.3 Construction of a calibration curve

Place 0 into colorimetric tubes; 0.3; 0.6; 0.9; 1.2; 1.5; 2.0 cm 3 of a solution of chlorides with an exact mass concentration of 10 μg / cm 3, which corresponds to 0; 3; 6; nine; 12; fifteen; 20 μg of chlorides, bring the volume to 5 cm 3 with water, add 0.5 cm 3 of an ammonium iron alum solution and 0.4 cm 3 of a thiocyanate solution and mix. After 10 minutes, the optical density of the calibration solutions is measured on a photoelectrocolorimeter at a wavelength of (480 ± 5) nm and a light-absorbing layer thickness of 10 mm with respect to a chloride-free solution.

Based on the data obtained, a calibration graph is built, plotting on the abscissa axis the masses of chlorides introduced into the calibration solutions in μg, and on the ordinate axis - the corresponding values ​​of optical densities.

Calibration solutions prepared simultaneously with samples can be used for visual determination. Solutions are stable for 1 hour.

A.5Taking measurements

1 - 5 cm 3 of the analyzed solution from the first absorption device and 5 cm 3 of the analyzed solution from the second absorption device are placed in colorimetric tubes, if necessary, the volume is adjusted to 5 cm 3 with water, 0.5 cm 3 of a solution of iron ammonium alum and 0.4 cm 3 solution of mercury rhodanite and proceed as described in 4.3. At the same time prepare a control solution for reagents. To do this, 5 cm 3 of water, 0.5 cm 3 of a solution of iron ammonium alum are placed in a colorimetric test tube and proceed further, as in 4.3. After 10 minutes, the optical densities of the analyzed solutions are measured in relation to the control solution for reagents and, according to the calibration curve, the masses of chlorides in the analyzed solutions are found in μg.

A.6Processing of measurement results

Mass concentration of hydrogen chloride X in air, mg / dm 3, calculated by the formula

P- barometric pressure during sampling, kPa;

t° - air temperature during the test, ° С: (101.33 kPa = 760 mm Hg)

INTERNATIONAL STANDARD ISO 905-76

With hydrochloric acid for industrial use. Estimation of hydrochloric acid concentration by measuring density

B.1Application area

This International Standard describes a method for estimating the approximate concentration of hydrochloric acid (HCl) by measuring the density of hydrochloric acid for industrial use.

B.2Principle

Determination of density at 20 °C by means of a hydrometer. Estimation of the appropriate concentration of hydrochloric acid (HCl)

B.3Equipment

Ordinary laboratory equipment.

B.3.1 Hydrometer, graduated at 0.005 g/cm3, calibrated at 20°C (see international organization standardization (R 649)).

B.3.2 Glass test tube, with a capacity of at least 500 cm 3 , with a diameter at least 25 mm greater than that of the hydrometer (3.1) and a height at least 25 mm greater than the immersion level of the hydrometer.

B.4Methodology

B.4.1 Density determination

Place about 500 ml of the test sample in a glass test tube (3.2). Adjust the temperature of the contents of the test tube to 20 ± 0.5 °C. Immerse the hydrometer (3.1) and, once static equilibrium has been reached, check again that the temperature of the acid is 20 ± 0.5 °C. Determine the density, which is indicated on the hydrometer scale.

B.4.2 Estimation of hydrochloric acid (HCl) content

Take from the table the concentration corresponding to the density shown by the hydrometer.

Table B.1 - The ratio of density and concentration of aqueous solutions of hydrochloric acid

* Saturation value at 20°C.

Note - The data shown in the table are obtained by graphical interpolation of the data presented in the International Handbook of Physical, Chemical and Technological Quantities, vol. 3, page 54, rounded to the first decimal place.

B.5Expression of results

Ascertain the density determined on the hydrometer scale, expressed in grams per cubic centimeter and the corresponding concentration of hydrochloric acid obtained from table B.1.

Tokey words: technical hydrochloric acid, hydrogen chloride, technical requirements, acceptance, safety measures, mass fraction, analysis result, transportation

6.9 Determination of the mass fraction of arsenic
6.9.1 The method is based on the distillation of arsenic compounds in the form of arsenic hydrogen and its further interaction with mercury bromide to form an orange compound, the color intensity of which is compared with the color intensity of a standard containing 0.002 and 0.004 mg of arsenic. The sensitivity of the method is 0.0001%.
6.9.2 Equipment, solutions, reagents:
- flasks Kn-2-100, 250 according to GOST 25336;
- pipettes 1.5-2.10 according to GOST 29169;
- volumetric flasks 2.2-100, 1000 according to GOST 1770;
- device for distillation of arsenic according to GOST 10485;
- cylinder 1.2-100 according to GOST 1770;
- hydrochloric acid according to GOST 3118, chemically pure, solution with a mass fraction of 15%;
- tin dichloride according to the current regulatory documentation - a solution with a mass fraction of 10%;
- tin granulated in accordance with the current regulatory documentation;
- zinc granulated in accordance with the current regulatory documentation;
- a solution of arsenic mass concentration of 1 mg/cm 3 prepared according to GOST 4212;
- distilled water according to GOST 6709;
- bromine-mercury paper, prepared according to GOST 4517.
6.9.3 Preparing for analysis
6.9.3.1 Preparation of stannous chloride solution
10 g of the reagent are dissolved in 15 cm 3 of hydrochloric acid (if necessary, the conical flask is heated). The solution is transferred into a volumetric flask with a ground stopper with a capacity of 100 cm 3, add 0.5 g of granulated tin, bring the volume to the mark with water. Weighing results are recorded to the second decimal place.
6.9.3.2 Preparation of 0.001 mg/cm 3 arsenic solution
Pipette 1 cm 3 of an arsenic solution prepared according to GOST 4212 into a volumetric flask with a capacity of 100 cm 3, bring the volume of the solution to the mark with water and mix. 10 cm 3 of the resulting solution is taken with a pipette, transferred to a volumetric flask with a capacity of 100 cm 3, the volume is adjusted to the mark with water and mixed. The solution is used freshly prepared.
6.9.4 Conducting analysis
The determination is carried out according to GOST 10485. To do this, 1.7 cm 3 (2 g) of the analyzed hydrochloric acid are taken with a pipette, placed in a flask of an instrument for the determination of arsenic containing 30 cm 3 of distilled water. At the same time, a reference solution is prepared: 30 cm 3 of distilled water are placed in the flask of the device and 2 cm 3 are added to one flask, and 4 cm 3 of an arsenic solution with a concentration of 0.001 mg / cm 3 are added to the second flask.
Then, 7 cm 3 of concentrated hydrochloric acid, 0.5 cm 3 of a solution of tin dichloride are added to both flasks. 5 g of zinc are added to each flask, and bromine-mercury paper is added to the nozzle. Close quickly with a stopper with a nozzle, gently mix with a rotary motion and leave alone for (90 ± 10) minutes. After this time, bromine-mercury papers are removed from the devices and the color intensity of the paper is compared with the analyzed solution and the reference solution.
The product complies with the established norm of the standard, if the color intensity of the paper from the analyzed hydrochloric acid solution matches or is less than the intensity of the reference solution.

6.10 Determination of the mass fraction of mercury
6.10.1 Determination of the mass fraction of mercury by the analyzer "Mercury-101"
6.10.1.1 The method is based on measuring the concentration of metallic mercury vapor in the gas phase by the atomic absorption of the resonant radiation of its atoms at a wavelength of 253.7 nm.
Sample preparation consists of boiling the sample in the presence of potassium dichromate to remove chlorine gas. Measurement range from 0.5% to 5·10 -4%.
6.10.1.2 Equipment, reagents, solutions:
- mercury analyzer type "Mercury-101" (or other device with similar metrological characteristics);
- flasks 2-100, 1000 according to GOST 1770;
- pipettes 1, 2, 6, 7-1, 2, 5, 10 according to GOST 29169;
- cylinder 3-100 according to GOST 1770;
- flasks Kn-1.50 according to GOST 25336;
- nitric acid according to GOST 4461, chemically pure;
- potassium dichromate according to GOST 4220, a solution with a concentration of 40 g / dm 3 (prepare as follows: 4 g of the reagent is dissolved in 100 cm 3 of water; stored in a flask with a ground stopper; weighing results are recorded to the second decimal place);
- the dilution solution is prepared as follows: 50 cm 3 of nitric acid, 5 cm 3 of potassium bichromate solution are placed in a volumetric flask with a capacity of 1000 cm 3 and brought to the mark with water;
- tin dichloride, a solution with a mass fraction of 10%, is prepared as follows: 10 g of the reagent is dissolved in a volumetric flask with a capacity of 100 cm 3 in 25 cm 3 of hydrochloric acid at boiling until the reagent is completely dissolved; after cooling to (20 ± 5) ° C, the volume is adjusted to the mark with water; the freshly prepared solution is cleaned of mercury by blowing with air for at least 5 minutes; use on the day of preparation; weighing results are recorded to the second decimal place;
- mercury (II) nitrate 1-aqueous according to GOST 4520, chemically pure, solution of concentration 0.01 μg / cm 3 (initial solution of concentration 1 mg / cm 3 is prepared according to GOST 4212 - solution A; a solution of concentration 0 is prepared by appropriate dilution ,01 µg/cm 3 , for which 10 cm 3 of solution A is placed in a volumetric flask with a capacity of 100 cm 3 and the volume is adjusted with a dilution solution to the mark - solution B with a concentration of 100 µg/cm 3; good for 3 months; 1 cm 3 of solution B place in a volumetric flask with a capacity of 100 cm 3 and bring the volume with a dilution solution to the mark - solution D with a concentration of 1 μg / cm 3, valid for 7 hours; 10 cm 3 of solution G are placed in a volumetric flask with a capacity of 100 cm 3 and bring the volume with a dilution solution labels - working solution with a concentration of 0.01 µg/cm 3 , valid for 7 hours);
- distilled water according to GOST 6709.
6.10.1.3 Safety requirements when working with the device "Mercury-101"
Persons who have studied the design of the device and have been instructed to work with electrical devices operating at a voltage of 1000 V are allowed to work. It is necessary to check the reliability of grounding before work. When repairing or replacing reagents, the instrument must be disconnected from the mains.
6.10.1.4 Preparing for analysis
The device is calibrated according to the passport (technical description and instructions) attached to the device.
6.10.1.5 Sample preparation
In pre-weighed two conical flasks containing (20±1) cm 3 of distilled water, place 10 g of the analyzed hydrochloric acid. Weighing results are recorded to the second decimal place. Then, up to 1 cm 3 of a potassium dichromate solution is added to the flasks and the samples are boiled for 5 minutes, provided that the yellow color of the potassium bichromate is preserved. Otherwise, add a solution of potassium dichromate in portions of 0.5 cm 3 . After cooling, the solution was quantitatively transferred into a volumetric flask with a capacity of 100 cm 3, adjusted to the mark with water (solution E).
At the same time, a control experiment is carried out under the same conditions, for which 20 cm 3 of water and the same amount of potassium dichromate are introduced into the same conical flask, which was used in the preparation of the sample. Boil 5 min. After cooling, the solution is transferred to a 100 cm 3 volumetric flask (solution E).
2 cm 3 of solution D are placed in a volumetric flask with a capacity of 100 cm 3 and the volume is adjusted to the mark with a dilution solution (solution D 1). Solution E is also diluted to give solution E 1 .
6.10.1.6 Perform analysis.
Solutions D 1 and E 1 are placed sequentially, starting with the control, into the analyzer reactor and the measurement is carried out according to the instructions for the device.
The analysis result is taken as the arithmetic mean of the analyzer readings for two parallel samples (a), the discrepancy between which does not exceed ±(10 + 0.05), where is the arithmetic mean of the analyzer readings for two parallel samples.
6.10.1.7 Handling results
Mass fraction of mercury X 4 %, calculated by the formula.

GOST 12.4.013-85 * System of labor safety standards. Goggles. General specifications

___________

* GOST R 12.4.013-97 1) applies on the territory of the Russian Federation.

GOST 3118-77 Reagents. Hydrochloric acid. Specifications

Norm for the brand

Analysis Methods

A OKP 21 2211 0100

B OKP 21 2211 0200

premium OKP 21 2211 0220

first grade OKP 21 2211 0230

1 Appearance

transparent colorless or
yellowish liquid

transparent
yellow liquid

2 Mass fraction of hydrogen chloride, %, not less than

3 Mass fraction of iron (Fe), %, no more

4 Mass fraction of residue after calcination, %, max

5 Mass fraction of free chlorine, %, no more

6 Mass fraction of arsenic (As),%, no more

7 Mass fraction of mercury (Hg), %, no more

Flask 2-250, 1000 according to GOST 1770;

Pipette 2-20 according to GOST 29169;

Cylinder 1.2-25 according to GOST 1770;

Sodium hydroxide according to GOST 4328, chemically pure, concentration solutionc(NaON) = 0.1 mol / dm 3, prepared according to GOST 25794.1;

Methyl orange (indicator), solution with a mass fraction of 0.1%; an aqueous solution is prepared according to GOST 4919.1;

Distilled water according to GOST 6709 and not containing carbon dioxide is prepared according to GOST 4517.

Flasks 1.2-50, 100, 250 and 1000 cm 3 according to GOST 1770;

Pipettes 1, 2, 5, 7-1, 25, 2, 5, 10 according to GOST 29169;

Hydrochloric acid according to GOST 3118, chemically pure, aqueous solution (1:1);

A muffle furnace with a thermocouple that maintains a temperature of (600 ± 10) °С;

Hourglass for 5 min.

As a result of the oxidation of methyl orange, the color of its solutions becomes less intense. The intensity of the color depends on the order of mixing the solutions, so the analyzed hydrochloric acid is added last with stirring. The method is selective, iron (III) interferes with the determination. Measuring range 5 10-4 - 8 10 -3%.

Pipettes 1.5-2.10 according to GOST 29169;

Volumetric flasks 2.2-100, 1000 according to GOST 1770;

Arsenic distillation device according to GOST 10485;

Cylinder 1.2-100 according to GOST 1770;

Hydrochloric acid according to GOST 3118, chemically pure, solution with a mass fraction of 15%;

Tin dichloride according to the current regulatory documentation - a solution with a mass fraction of 10%;

Tin granulated in accordance with the current regulatory documentation;

Zinc granulated in accordance with the current regulatory documentation;

A solution of arsenic mass concentration of 1 mg/cm 3 prepared according to GOST 4212;

Distilled water according to GOST 6709;

Bromine-mercury paper, prepared according to GOST 4517.

Nitric acid according to GOST 4461, chemically pure;

Potassium dichromate according to GOST 4220, a solution with a concentration of 40 g / dm 3 (prepared as follows: 4 g of the reagent is dissolved in 100 cm 3 of water; stored in a flask with a ground stopper; weighing results are recorded to the second decimal place);

The dilution solution is prepared as follows: 50 cm 3 of nitric acid, 5 cm 3 of potassium bichromate solution are placed in a volumetric flask with a capacity of 1000 cm 3 and brought to the mark with water;

Tin dichloride, a solution with a mass fraction of 10%, is prepared as follows: 10 g of the reagent is dissolved in a volumetric flask with a capacity of 100 cm 3 in 25 cm 3 of hydrochloric acid at boiling until the reagent is completely dissolved; after cooling to (20 ± 5) °С, the volume is adjusted to the mark with water; the freshly prepared solution is cleaned of mercury by blowing with air for at least 5 minutes; use on the day of preparation; weighing results are recorded to the second decimal place;

Mercury (II) nitrate 1-aqueous according to GOST 4520, chemically pure, solution of concentration 0.01 μg / cm 3 (initial solution of concentration 1 mg / cm 3 is prepared according to GOST 4212 - solution A; a solution of concentration 0 is prepared by appropriate dilution, 01 μg / cm 3, for which 10 cm 3 of solution A is placed in a volumetric flask with a capacity of 100 cm 3 and the volume is adjusted with a dilution solution to the mark - solution B with a concentration of 100 μg / cm 3; good for 3 months; 1 cm 3 of solution B is placed into a volumetric flask with a capacity of 100 cm 3 and bring the volume with a dilution solution to the mark - solution D with a concentration of 1 μg / cm 3, valid for 7 hours; 10 cm 3 of solution D is placed in a volumetric flask with a capacity of 100 cm 3 and the volume is adjusted with a dilution solution to the mark - working solution with a concentration of 0.01 µg/cm 3 , valid for 7 hours);

Distilled water according to GOST 6709.

An exemplary solution of mercury is prepared according to GOST 4212 or as follows: 0.1079 g of mercury oxide is dissolved by heating slightly in 2 - 3 cm 3 of concentrated nitric acid and adjusted to 100 cm 3 with water; 1 cm 3 of the resulting solution contains 1 mg of mercury; dilution prepare a solution containing 0.010 mg of mercury in 1 cm 3; Weighing results are recorded to the fourth decimal place:

Universal indicator paper;

Distilled water according to GOST 6709;

Photoelectrocolorimeter FEK-56 or a similar device with a given accuracy and sensitivity;

6.10.2.2 Construction of a calibration graph

AT five separating funnels with a capacity of 250 cm 3 contribute 50 cm 3 of water, 1, 2, 3, 4 and 5 cm 3 of a diluted standard solution of mercury, which corresponds to 0.010; 0.020; 0.030; 0.040 and 0.050 mg of mercury, 5 cm 3 of a solution of Trilon B, 10 cm 3 of a buffer solution, stirred for 1 min, 5 cm 3 of chloroform were added, stirred again for 1 min, and after settling, the chloroform was discarded. Then add 10 cm 3 of solution B (ditizone) and shake for 2 minutes. In parallel, prepare a control solution containing all reagents except mercury under the same conditions.

P After phase separation, the chloroform layer is separated and the optical density is measured on a photoelectric colorimeter in a cuvette with a light-absorbing solution layer thickness of 0.5 cm with a light filter 8. Reference solution - chloroform.

G the calibration graph is built in the coordinates "optical density - mercury concentration, mg".

6.10.2.3 Conducting an analysis

5 cm 3 analyzed acid is placed in a beaker with a capacity of 100 cm 3 and add water to 30 cm 3 . The contents of the beaker, after cooling, are slowly neutralized with ammonia solution to pH 4 according to indicator paper, water is added to 50 cm 3, 5 cm 3 of Trilon B solution, 10 cm 3 of buffer solution, 1 - 3 cm 3 of hydroxylamine solution. After 10 minutes, the solution is transferred to a separating funnel with a capacity of 250 cm 3 , 5 cm 3 of chloroform are added, stirred, and after settling, the chloroform layer is discarded.

D then proceed as described in .

D To check the purity of the reagents, a control experiment is carried out, for which 50 cm 3 of water are placed in a separating funnel with a capacity of 250 cm 3, 5 cm 3 of Trilon B, 10 cm 3 of a buffer solution, 1 - 3 cm 3 of a hydroxylamine solution are introduced. After 10 min, 5 cm 3 of chloroform are added, stirred for 1 min, and after settling, the chloroform layer is discarded. Extraction and determination of mercury is carried out as described in .

6. 10.2.4 Handling results

M mass share X 6 , %, calculated by the formula

where m 1 - mass of mercury in the analyzed sample, found according to the calibration curve, mg;

m 2 - mass of mercury found in the control experiment, mg;

V - the volume of hydrochloric acid taken for analysis, cm 3;

HYDROchlorIC ACID SYNTHETIC TECHNICAL

GOST 857-95, STO 00203275-233-2009

CHEMICAL FORMULA HCl

MOLECULAR WEIGHT 36.46

APPLICATION:

In the chemical industry in the production of dyes, mineral fertilizers, coagulants and other chemical compounds; in the food industry for washing equipment, obtaining a protein sausage casing, ethyl alcohol and molasses; in non-ferrous and ferrous metallurgy for etching and preparation of metal surfaces for electroplating, as well as in the medical industry.

Container, Packing, Transportation, Storage.

According to GOST 857-95, synthetic hydrochloric acid is calibrated in special rubber-lined railway tanks. According to STO 00203275-233-2009, synthetic hydrochloric acid is poured into special rubberized automobile tanks; special containers with a capacity of 1000 dm3, consisting of a metal crate, a wooden pallet and a plastic container.

Railway and by car in accordance with the rules for the transport of dangerous goods in force for this type of transport. Stored in sealed containers made of materials resistant to hydrochloric acid. The shelf life of the product is not limited.

SPECIAL SAFETY FEATURES:

Corrosive, non-flammable liquid. In the air "smoke". Hydrochloric acid vapors irritate the upper respiratory tract and mucous membranes of the eyes. Causes burns on contact with skin. Dangerous product. When working with acid, the use of personal protective equipment is mandatory. Gloves KShch, Gas mask, Chemical protection.