GB/T 4701.3-2009Ferrotitanium - Determination of copper content - The DDTC photometric method and the flame atomic absorption spectrometric method (English PDF)

3.1 Principle

Sample with nitric acid, hydrofluoric acid dissolved, add citric acid masking iron, titanium and other interfering elements in ammonia solution, add diethyl dithiocarbamate

Sodium (DDTC) with brown colloidal solution form insoluble copper, gum arabic solution was added after the spectrophotometer at a wavelength of 460nm, measured

The amount of its absorbance on the calibration curve have to check the quality of copper, calculated content of copper in the sample.

3.2 Reagents and materials

Unless otherwise indicated in the analysis using only recognized as analytical grade reagents and distilled water or its equivalent purity water.

3.2.1

urea, solid.

3.2.2

hydrofluoric acid, rho1.15g/mL.

3.2.3

nitrate, 2 + 1.

3.2.4

ammonia, 1 + 1.

3.2.5

boric acid solution, 50g/L.

3.2.6

ammonium citrate solution, 500g/L.

3.2.7

DDTC solution, 2g/L.

3.2.8 gum arabic solution, 10g/L

Weigh 2g gum arabic, dissolved in 100mL of hot water, joined a fine thymol, with removal

After fat cotton filter, diluted with water to 200mL, and mix.

3.2.9 copper standard solution

Weigh 0.5000g copper (Cu>=99.9%), placed in a beaker of 200mL, 30mL of nitric acid was added (3 + 5), dissolved by heating to boil and removing nitrogen oxides, was cooled to room temperature, transferred to 1000mL volumetric flask, dilute to volume with water, mix uniform. This solution 1mL copper 500µg.

3.3 Instrument

Analysis using common laboratory instruments.

3.4 Sampling and Preparation

In accordance with the provisions of GB/T 4010 will be sampling and sample preparation, the sample should be adopted 0.125mm sieve.