SU1460701A1 - Method of photometric analysis of germanium - Google Patents

Abstract

The invention relates to analytical chemistry, can be used for the analysis of semiconductor materials, natural and waste waters, alloys, and reduces the detection limit of germanium. Molybdogermanic acid is obtained; it is reduced, reacted with chromium pyrazole in 1.1-1.8 M sulfuric acid, the resulting compound is floated with a mixture of toluene and acetone, and dissolved in acetone, followed by photometric measurement of the organic solution. The detection limit is 6 µg / L (in solid samples). Only elements that form heteropoly acids under the same conditions interfere with the determination. 1 tab. with

Description

one

- The invention relates to analytical chemistry, specifically to spectrophotometric methods for the determination of germanium, which can be used to determine germanium in waters, natural objects and semiconductor materials.

The purpose of the invention is to reduce the detection limit of germanium.

Example 1 Into six six-dimensional flasks with a capacity of 25 ml are introduced from 0.2 to 0, 1 ml with an interval of 0.2 ml of a standard solution of germanium dioxide (5 µg / ml), a pH of 1-2 is created, 5 ml of 0 is added. 13% ammonium molybdenum solution, 3 ml of 1 M hydrochloric acid solution, 1 ml of 0.3% ascorbic acid solution and water to 15 - 20 ml. The solutions are heated in a water bath for 20 minutes. After cooling, 5 ml of 6 M are added and

1 ml 6 10g M solution of chrompyrazole. Transfer the solutions to a 100 ml separator cable with a capacity of 100 ml, add 5 ml of a mixture (1: 1) of toluene with acetone and shake for 2 minutes. The aqueous phase is separated and 5 ml of acetone is added to the organic one. The optical density of organic solutions is measured relatively similarly to the prepared solution of the blank run on a spectrophotometer at 590 im in cuvettes with a length of 1 cm. Based on the data obtained, a calibration curve is drawn. The value of the molar absorption coefficient (2.6t; l, 3)

-40

The determination of germanium by the proposed method is hindered only by the elements that form, under the conditions of the analysis of the heteropoly acid: silicon, phosphorus, and mouse.

EXAMPLE 2. The determination was carried out according to the procedure given in Example 1. The amount varies.

1.0 Floated chrompyrazole molybdate

Germanium is placed in a 25 ml flask and the determination of germanium is carried out under the conditions described in Example 1.

In a sample of cadmium sulfide doped with germanium, (5.910.5) "10% germanium was found (as determined with phenylfluorone (5.8fO) - 10%). By a known method, the detection limit is 150 µg / l germanium, therefore determination of such small amounts of cadmium sulfide is impossible. Thus, the proposed method allows to reduce the detection limit to 6 µg / l and to avoid strict regulation of the acidity of the medium during the formation and flotation of the compound.

Example 3 To determine the germanium in cadmium sulfide samples, weighed 0.2 g of the solution with weak heating in 5 ml of a 6 M solution of hydrochloric acid, allowed to stand until hydrogen sulphide was released, diluted with double distilled water to about 10 ml, adjust the pH to 1-2 with concentrated ammonia and quantitatively transferred into a 25 ml volumetric flask; 5 ml of diluent sample containing 0.5–5 µg

Claims (1)

Invention Formula 20 A method for the photometric determination of germanium in the form of an ionic associate of molybdogermanic acid with chromium pyrazole, characterized in that, in order to lower the limit detection, molybdogermanic acid is reduced by ascorbic acid, and the formation of an ionic associate is carried out with reduced 30 molybdogermanic acid in a medium of 1.1-1.8 M sulfuric acid, followed by flotation of the obtained compound and dissolving in acetone.