GOST 22519.4-77

• gost-225194-77.pdf (132.45 KiB)
  ГОСТ 22519.4-77

GOST 22519.4−77 Thallium. Method for the determination of sulfur (with Amendments No. 1, 2, 3)

GOST 22519.4−77

Group B59

STATE STANDARD OF THE USSR

THALLIUM

Method for the determination of sulfur

THALLIUM. Method for the determination of sulphur

AXTU 1709

Date of introduction 1978−01−01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR

DEVELOPERS

A. P. Sychev, M. G. Sun, V. I. Lysenko, I. A. Romanenko, V. A. Kolesnikov

2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from 10.05.77 N 1171

Change No. 3 adopted by the Interstate Council for standardization, Metrology and certification (Protocol No. 4 dated 21.10.93)

The adoption voted:

3. INTRODUCED FOR THE FIRST TIME

4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

5. Limitation of actions taken on the Protocol, the Interstate Council for standardization, Metrology and certification (ICS 2−93)

6. REPRINT (February 1998) with Amendments No. 1, 2, 3, approved in January 1983, March 1987-June 1996 (IUS 5−83, 6−87, 9−96)

This standard specifies the nephelometric method for the determination of sulphur (at a mass proportion of from 0.0005 to 0.001%) in thallium brands TL0 GOST 18337*.
______________
* On the territory of the Russian Federation GOST 18337−95. — Note the manufacturer’s database.

Nephelometric determination of sulfur based on the formation of a suspension of barium sulphate in hydrochloric glycerol medium and measuring its optical density on a photoelectrocolorimeter with a filter for nephelometric determinations. Pre-separated thallium by extraction with ether from the environment containing the hydrochloric acid is 6 mol/DM.

The sensitivity of the method was 10 µg in a volume of 25 cm.

(Changed edition, Rev. N 2, 3).

1. GENERAL REQUIREMENTS

1.1. General requirements for method of analysis and security requirements — according to GOST 22519.0.

(Changed edition, Rev. N 3).

2. APPARATUS, REAGENTS AND SOLUTIONS

Photoelectrocolorimeter — nephelometer.

Filter.

Nitric acid according to GOST 4461.

Hydrochloric acid according to GOST 3118, diluted 1:1.

Glycerin distilled according to GOST 6824, grade dynamite.

Barium chloride according to GOST 4108, a solution of 100 g/DM.

Sodium sulphate anhydrous according to GOST 4166.

Standard solutions of sulfur.

Solution A, prepared as follows: 1,109 g of anhydrous sodium sulfate is dissolved in water, transferred to a volumetric flask with a capacity of 500 cm, was adjusted to the mark with water and mix.

1 cmof solution A contains 0.5 mg of sulfur.

Solution B is prepared as follows: 2 cmof solution A is placed in a volumetric flask with a capacity of 100 cm, is diluted to the mark with water and mix.

1 cmof a solution containing 10 mcg.

Solution B using freshly prepared.

Diethyl ether (medical).

Bromine according to GOST 4109.

(Changed edition, Rev. N 2).

3. ANALYSIS

3.1. The weight of thallium in a weight of 1,000 g dissolved in 5 cmof nitric acid and boil to remove oxides of nitrogen. Add 5 cmof hydrochloric acid diluted 1:1, heated to dissolve the precipitate and discoloration of the solution. The solution was quantitatively transferred to a separating funnel, poured 15 cmof ether and shaken for 1 min. After phase separation, the aqueous layer drained into another separating funnel, add 1 cmof bromine, 15 cmof ether and the extraction repeated. The aqueous layer is drained into a glass with a capacity of 50 cmand evaporated to a moist residue. Pour 1 cmof hydrochloric acid diluted 1:1, 10 cmof water, the solution was transferred to volumetric flask with a capacity of 25 cm, 5 cm pour theglycerin, mix, pour 3 cmof a solution of barium chloride, diluted to the mark with water and mix.

After 1 h, measure the optical density of the solution on the photoelectrocolorimeter in a ditch with the thickness of the light absorbing layer 50 mm, applying a filter for nephelometric measurements. Before pouring the solution in the cuvette several times to mix. Solution comparison is water.

The amount of sulfur in nephelometry the solution set for the calibration schedule.

(Changed edition, Rev. N 2

3).the

3.2. Construction of calibration curve

In six volumetric flasks with a capacity of 25 cmmeasure 0; 1,0; 2,0; 3,0; 4,0 and 5,0 cmstandard solution B, which corresponds to 0, 10, 20, 30, 40 and 50 µg of sulfur poured into each 1 cmof hydrochloric acid diluted 1:1, water to a volume of 15 cm, and 5 cmof glycerin and further analysis are as indicated in claim 3.1.

On the found values of optical densities and corresponding sulfur contents build the calibration graph.

(Changed edition, Rev. N 2).

4. PROCESSING OF THE RESULTS

4.1. Mass fraction of sulfur () in percent is calculated by the formula

,

where is the mass of sulfur was found in the calibration schedule, mcg;

the weight of thallium,

(Changed edition, Rev. N 2).

4.2. The absolute values of the differences between the results of two parallel measurements (rate of convergence) with confidence probability of 0.95 does not exceed 0,0003%, and the results of two tests (a measure of reproducibility) — 0,0004%.

(Changed edition, Rev. N 3).