GB/T 3260.3-2013Methods for chemical analysis of tin - Part 3: Determination of bismuth content KI photometric method and flame atomic absorption spectrometric method (English PDF)

2.1 Method summary

Samples with hydrochloric acid, nitric acid is completely dissolved in sulfuric acid medium, hydrochloric acid - hydrobromide exclude a large number of tin in hydrochloric acid medium, and bismuth potassium iodide

Forming a yellow complex was measured at 460nm wavelength spectrophotometer absorbance of bismuth.

2.2 Reagents

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

2.2.1

hydrochloric acid (rho1.19g/mL).

2.2.2

nitrate (rho1.42g/mL).

2.2.3

sulfate (rho1.84g/mL).

2.2.4 hydrobromide

The excellent pure or analytical reagents sub-boiling distillation using a concentration of not less than 8.5mol/L.

2.2.5 hydrochloric acid - mixed nitric acid

hydrochloric acid, nitric acid (31), using now.

Hydrochloric 2.2.6 - hydrobromic acid. hydrochloric acid hydrobromide (11).

2.2.7

sulfuric acid (11).

2.2.8

hydrochloric acid (19).

2.2.9

citric acid solution (500g/L).

2.2.10

KI solution (200g/L).

2.2.11

thiourea solution (100g/L).

2.2.12 bismuth standard stock solution

Weigh 0.5000g bismuth (wBi>=99.99%) in 200mL beaker, add 10mL of nitric acid (12), low-temperature heating dissolution is complete, add 20mL sulfuric acid (2.2.7), is heated and evaporated to white smoke, removed, cooled to room temperature, with little

Beibi water purge, and then evaporated to white smoke cooling. Hydrochloric acid was added 20mmL (2.2.8), dissolved salts on low heat, cool. Hydrochloric acid (2.2.8) moved into 1000mL volumetric flask, and dilute to volume, and mix. This solution 1mL containing 500µg bismuth.

2.2.13 bismuth standard solution

Pipette 20.00mL bismuth standard stock solution (2.2.12) in 500mL flask with hydrochloric acid (2.2.8) diluted

To the mark, and mix. This solution 1mL containing 20µg bismuth.