GB/T 4324.10-2012Methods for chemical analysis of tungsten - Part 10: Determination of copper content - Flame atomic absorption spectrometry (English PDF)

1 Scope

This section GB/T 4324 provisions of the tungsten powder, tungsten, tungsten carbide, tungsten trioxide, tungstic acid, tungsten blue, purple tungsten, ammonium paratungstate, ammonium metatungstate

Determination of copper content.

This Part applies to tungsten powder, tungsten measure, tungsten carbide, tungsten trioxide, tungstic acid, tungsten blue, purple tungsten, ammonium paratungstate, metatungstate copper content set. Determination of the range of 0.0003% to 0.0030%.

2 principle of the method

Tungsten powder, tungsten bar, fine tungsten carbide, tungsten trioxide, tungstic acid, tungsten blue, ammonium paratungstate, ammonium metatungstate with hydrogen peroxide and ammonia decomposition; purple tungsten, crude

Particles of tungsten carbide into tungsten trioxide after burning hydrogen peroxide and ammonia decomposition; hydrochloric acid was added so that the tungsten fully hydrolyzed and dry filtered to remove the tungsten substrate,

Take serum atomic absorption spectrometer 324.7nm wavelength in air - acetylene flame, working curve method Determination of copper.

3 Reagents and materials

Unless otherwise indicated, as used in the analysis confirmed that only pure reagents superior grade and distilled or deionized water or equivalent purity.

4 Instrument

Atomic absorption spectrometer, with copper hollow cathode lamp.

Under optimum working conditions for those who can reach the following indicators can be used.

--- Characteristic concentration. a solution in the measurement matrix consistent solution features quality copper concentration is not more than 0.04µg/mL;

--- Precision. standard solution with the highest concentration of 10 times the absorbance measurements, the standard deviation should not exceed the average absorbance of 1.0%;

With the lowest concentration of standard solution (not a zero concentration standard solution) measuring the absorbance of 10 times, the standard deviation should not exceed the maximum concentration

0.5% of the mean absorbance of the standard solution;

--- Linear curve. the curve according to concentration, is divided into five sections, the difference between the absorbance of the absorbance difference between the highest and the lowest segment of the segment

Ratio of not less than 0.7.