GB/T 3253.1-2008Methods for chemical analysis of antimony and antimony trioxide - Determination of arsenic content - Arsenic molybdenum blue spectrophotometric method (English PDF)

3.1 commercially available reagents

3.1.1

sulfate (rho1.84g/mL).

3.1.2

hydrochloric acid (rho1.19g/mL).

3.1.3 Benzene

3.2 solution

3.2.1

sulfuric acid (1 + 20).

3.2.2

sulfuric acid (1 + 1).

3.2.3

sulfite (1 + 2).

3.2.4 sodium hydroxide solution (300g/L)

stored in a plastic bottle.

3.2.5 iodine solution (5g/L)

Weigh 0.5g iodine, 1g of potassium iodide in 250mL beaker, 5mL water was added to dissolve, dilute to

100mL, stored in a brown bottle.

3.2.6 ammonium molybdate solution (15g/L)

Weigh 1.5g of ammonium molybdate [(NH4) 6Mo7O24 · 4H2O] placed in 250mL beaker, add

40mL water, 50mL was added sulfuric acid (3.2.2), transferred to a glass bottle after cooling. Diluted with water to 100mL, and mix.

3.2.7

hydrazine sulfate solution (0.5g/L).

3.2.8

phenolphthalein ethanol solution (1g/L).

3.3 standard solution

3.3.1 arsenic standard stock solution

Accurately weigh 0.1320g benchmark arsenic trioxide (>=99.9%, advance after 100 °C ~ 110 °C drying 2h placed in a desiccator cold

To room temperature), was added 20mL of sodium hydroxide solution (50g/L) was dissolved clear, was added 100mL of water, 10 mL of sulfuric acid (3.2.2) and transferred to

1000mL volumetric flask, dilute with water to volume, and mix. This solution 1mL containing 100µg arsenic.

3.3.2 arsenic standard solution

Pipette 10.00mL arsenic standard stock solution (3.3.1) in 100mL volumetric flask, dilute with water to volume, and mix. This solution

1mL containing 10µg arsenic.