GB/T 4324.9-2012Methods for chemical analysis of tungsten - Part 9: Determination of cadmium content - Inductively coupled plasma atomic emission spectrometry and flame atomic absorption spectrometry (English PDF)

2.1

Unless otherwise indicated, this part of the reagents used are in line with national standards or industry standard analytical reagent, the water are distilled water.

2.2

tungsten should smash through the 0.12mm sieve.

2.3

average particle size of the tungsten carbide fine particles 1µm ~ 3µm, the average particle size of the tungsten carbide particles is greater than 3µm ~ 9µm, coarse carbide particles

Tungsten average particle size greater than 9µm.

3 a method of inductively coupled plasma atomic emission spectrometry

3.1 Method summary

Tungsten powder, tungsten, tungsten carbide fine particles dissolved hydrogen peroxide, tungsten trioxide, tungstic acid, ammonium paratungstate and ammonium metatungstate dissolved with ammonia, blue tungsten

Hydrogen peroxide and ammonia dissolved purple tungsten, tungsten carbide coarse particles oxidized to trioxide with ammonia dissolved after tungsten, tungsten complex citrate, hydrochloric acid solution was added

Solutions of cadmium and cadmium content in inductively coupled plasma emission spectrometer.

3.2 Reagents

3.2.1

Hydrogen peroxide (rho = 1.10g/mL).

3.2.2

nitric acid (11).

3.2.3

ammonia (11).

3.2.4

citric acid solution (500g/L).

3.2.5

hydrochloric acid (11).

3.2.6 cadmium standard stock solution

Weigh 1.0000g metal cadmium (wCd>=99.99%) in 250mL beaker with a small amount of water wet, add

Into 20mL nitrate (3.2.2), covered with a watch glass, low heat until completely dissolved, cooled to room temperature, the solution is transferred 1000mL volumetric flask

Diluted with water to volume, and mix. This solution 1mL 1mg containing cadmium.

3.2.7 Cadmium standard solution

Pipette 5.00mL cadmium standard stock solution (3.2.6) into 100mL volumetric flask, nitric acid is added 1mL (3.2.2), dilute with water to volume, and mix. This solution 1mL containing 50µg cadmium.

3.2.8 Tungsten Substrate

cadmium mass fraction of less than 0.0001%.