GB/T 20899.14-2017Methods for chemical analysis of gold ores-Part 14: Determination of thallium content - Inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry (English PDF)

2.1 Method principle

Samples of hydrochloric acid, nitric acid, hydrofluoric acid, perchloric acid decomposition, mixed acid medium, in the presence of hydrogen peroxide and iron salts, with polyurethane foam rich Set, the separation of thallium and impurity elements, dissolved in boiling water bath with dilute nitric acid thallium, selected by inductively coupled plasma atomic emission spectrometer The spectral intensity of the thallium element in the test solution is measured at a wavelength of 190.801 nm and the amount of thallium is calculated according to a standard curve method.

2.2 Reagents and materials

Unless otherwise specified, only reagents and materials identified as analytically pure, and deionized or distilled water or equivalent purity water are used in the assay.

2.2.1 Hydrochloric acid (p = 1.19 g/mL).

2.2.2 Nitric acid (p = 1.42 g/mL).

2.2.3 Hydrofluoric acid (p = 1.13 g/mL).

2.2.4 Perchloric acid (rho = 1.68g/mL).

2.2.5 Hydrogen peroxide (30%).

2.2.6 Hydrochloric acid (19).1 volume hydrochloric acid (2.2.1) mixed with 9 volumes of water.

2.2.7 Nitric acid (1 99).1 volume of nitric acid (2.2.2) mixed with 99 volumes of water.

2.2.8 Mixed acid (1 1).3 volume hydrochloric acid (2.2.1), a volume of nitric acid (2.2.2) and 4 volumes of water, the current use of the current distribution.

2.2.9 Ferric chloride solution (50g/L). Weigh 242.5g FeCl3 · 6H2O in 500mL beaker, dissolved in water, was added 30mL Mixed acid (2.2.8), into the 1000mL volumetric flask, diluted with water to the mark, mix well.

2.2.10 Thallium standard stock solution Weigh 0.1117g pre-baked at 100 °C ~ 105 °C 1h and cooled to room temperature in the dryer trioxide thallium (reference reagent), placed in 100mL beaker, add 10mL hydrochloric acid (2.2.1), to dissolve. Into a 100mL volumetric flask, add 10mL nitric acid (2.2.2), diluted with water to the mark, mix well. 1mL of this solution contains 1mg thallium.

2.2.11 Thallium standard solution A (50.00µg/mL) Pipette 5.00mL thallium standard stock solution (2.2.10) in 100mL volumetric flask, add 10mL nitric acid (2.2.2), diluted with water to the mark, mix well. 1 mL of this solution contains 50 µg thallium.

2.2.12 Thallium standard solution B (2.50µg/mL) Pipette 5.00mL thallium standard solution A (2.2.11) in a 100mL volumetric flask, add.