GOST 22519.6-77

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  ГОСТ 22519.6-77

GOST 22519.6−77 Thallium. Method for determination of lead and India (with Amendments No. 1, 2, 3)

GOST 22519.6−77

Group B59

STATE STANDARD OF THE USSR

THALLIUM

Method for determination of lead and India

THALLIUM. Method for the determination of lead and indium

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 sets the polarographic method for the determination of lead (with a mass fraction of lead 0.00005 to 0.01%) and India (in India the mass fraction of 0.00005 to 0.0001%) in thallium brands Tl00, TL0 and TL1 GOST 18337*.
______________
* On the territory of the Russian Federation GOST 18337−95. — Note the manufacturer’s database.

The method is based on preliminary separation of lead and indium on the iron hydroxide, extraction causatives of thallium and their polarographic determination against the background of a hydrochloric acid solution of 3 mol/DMin the range of polarization dripping mercuric electrode from minus 0.3 to minus 0.8 V relative to the saturated calomel or mercury electrodes in the internal comparison.

(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

Polarograph polarograph oscilloscope or AC of any type.

Funnel glass filter No. 2 type VF with a diameter of 28−30 mm according to GOST 23932.

Nitric acid according to GOST 4461, diluted 1:1 and 1:3.

Hydrochloric acid according to GOST 3118 and diluted 1:1 (saturated with bromine), and 1:3.

Bromatologia acid according to GOST 2062.

Perchloric acid, 57% solution (8.5 mol/DM).

Bromine according to GOST 4109.

Iron nitrate, a solution of 70 g/DM.

Iron powder restored brand MLB-1 according to GOST 9849.

Sanitarily sodium (sodium sulfite), a solution of 100 g/DM.

Indium GOST 10297, brand Ин0.

Lead according to GOST 3778*, mark S0.
______________
* On the territory of the Russian Federation GOST 3778−98. — Note the manufacturer’s database.

Standard solutions of lead

Solution A, prepared as follows: a portion of the lead weight 0,100 g dissolved in 50 cmof nitric acid, diluted 1:3, cooled, quantitatively transferred to a volumetric flask with a capacity of 1 DM, dilute to the mark with water and mix.

1 cmof solution A contains 0.1 mg of lead.

Solution B is prepared as follows: 10 cmof standard lead solution And placed in a volumetric flask with a capacity of 100 cm, flow 10 cmof nitric acid, diluted 1:3, dilute to the mark with water and mix.

1 cmof a solution contains 0.01 mg of lead.

Standard solutions India

Solution A, prepared as follows: the weight India weight 0,100 g dissolved in 50 cmof nitric acid, diluted 1:1, cooled, quantitatively transferred to a volumetric flask with a capacity of 1 DM, dilute to the mark with water and mix.

1 cmof solution A contains 0.1 mg India.

Solution B is prepared as follows: 10 cmstandard solution And placed in a volumetric flask with a capacity of 100 cm, flow 10 cmof nitric acid, diluted 1:3, dilute to the mark with water and mix.

1 cmof solution B contains 0.01 mg India.

Solution; prepared as follows: 1 cmof the standard solution And placed in a volumetric flask with a capacity of 100 cm, flow 10 cmof nitric acid, diluted 1:3, dilute to the mark with water and mix.

1 cmof the solution contains 0.001 mg India.

The solution used freshly.

Calibration solutions of lead and indium; prepared as follows: batches of thallium weight of 1,000 or 5,000 g (see table.1) before their decomposition to nitric acid, measured with micropipettes standard solutions of lead and indium and further conduct training, as specified in sec. 3. The dilution of the volume of the solution samples with additives and concentrations of additives in them are shown in table.1.

Table 1

Live-, -dialogically (hloreksa).

Mercury GOST 4658.

(Changed edition, Rev. N 2, 3).

3. ANALYSIS

3.1. In a conical flask with a capacity of 100 cmis placed a portion of the thallium weighing 1,000 g (with mass fraction of thallium 99,98−99,99%) or 5,000 g (with mass fraction of thallium 99,999-of 99.9995%), and poured respectively 10 and 20 cmof nitric acid, diluted 1:1, boil to remove oxides of nitrogen, flow 50 cmwater, 1 cmof solution of nitrate of iron, poured the ammonia to perceptible odor, and then 2 cmin excess. Pour 2 cmof a solution of sodium sulphite precipitated and coagulated to precipitate the hydroxides of iron, lead and indium in a warm place for 20−25 min. the Precipitate was filtered off on a glass filter and washed four times with hot water. The filtrate with the washings discarded.

The filter cake is dissolved in 20 cmof hydrochloric acid diluted 1:1, saturated with bromine, in small quantities and collect the solution in the flask in which to carry out the precipitation of metal hydroxides. The solution was transferred to a separatory funnel with a capacity of 100−120 cm, flow 20 cmhloreksa, one or two drops of bromine and extracted thallium with moderate shaking for 2 min. the Organic layer is decanted, poured another 20 cmhloreksa, one drop of bromine and the extraction of thallium repeat. The organic layer after settling, carefully and completely drain through the valve, the water layer is poured through the neck of the funnel in a Cup with a capacity of 50 cm. Pour 2 cmbromatological acid and evaporated to a volume of 1−2 cm. Pour 1 cmof perchloric and nitric acids, and evaporated to stop the allocation of fumes of perchloric acid.

To the residue poured with a pipette 5; 10 or 20 cmof hydrochloric acid diluted 1:3, sprinkle about 0.5 g of iron powder, leave to restore the ferric iron (up to bleaching), transfer the contents of the Cup into the cell, holding the particles of iron at the bottom of the magnet, and conduct polarographically lead and India at optimum sensitivity oscilloscope or alternating current polarography within polarization dripping mercuric electrode from minus 0.3 to minus 0.8 V relative to the saturated calomel or mercury electrodes in the internal comparison.

Similarly polarografic the calibration solutions and the control solution sample. Subtract the value of the wave height in the reference experiment from the height of the wave samples and process the results of the analysis.

The oscillographic polarograph used in the analysis of lead and indium in thallium with mass fraction of its 99,98−99,99%.

(Changed edition, Rev. N 3).

4. PROCESSING OF THE RESULTS

4.1. Mass fraction of lead or indium (in) in percent is calculated by the formula

,

where wave height lead or India when polarography of the sample solution, mm;

 — wave height in lead or India when polarographically sample with standard addition, mm;

the weight of thallium, g;

 — the volume of the sample solution, cm;

 — mass concentration of standard addition of lead (India) in calibration solution, mg/DM

.

4.2. The absolute values of the differences between the results of two parallel measurements (rate of convergence) and the results of the two tests (index of reproducibility) with confidence probability of 0.95 does not exceed values of allowable differences specified in table.2.

Table 2

4.1, 4.2. (Changed edition, Rev. N 3).