GB/T 39138.3-2020Methods for chemical analysis of gold nickel chromium iron silicon boron alloys - Part 3: Determination of chromium, iron, silicon and boron contents - Inductively coupled plasma atomic emission spectrometry (English PDF)

3.1

Hydrochloric acid (rho=1.19g/mL).

3.2

Nitric acid (rho=1.42g/mL).

3.3

Hydrofluoric acid (rho=1.12g/mL), excellent grade pure.

3.4

Boric acid solution (50g/L).

3.5 Chromium standard storage solution

Weigh 0.1000g metallic chromium (mass fraction >=99.99%), place it in a 250mL beaker, and add 10mL

Hydrochloric acid (3.1), 1mL nitric acid (3.2), cover with a watch glass, and heat at low temperature to dissolve completely. Cool to room temperature. Transfer to a 100mL volumetric flask, use

Dilute to the mark with water and mix well. This solution 1mL contains 1000µg chromium.

3.6 Iron standard storage solution

Weigh 0.1000g of metal iron powder (mass fraction >=99.99%), place it in a 250mL beaker, and add 10mL

Hydrochloric acid (3.1), cover with a watch glass, heat at low temperature to dissolve completely, transfer to a 100mL volumetric flask, dilute to the mark with water. Mix well. This solution

1mL contains 1000µg iron.

3.7 Silicon standard storage solution

Weigh 0.1000g elemental silicon (mass fraction >=99.99%), place it in a polytetrafluoroethylene digestion tank, and add 2g

Potassium hydroxide, put it in the oven, dissolve it at 150°C for 16h, take it out, cool it, and transfer it into a 100mL plastic volumetric flask, dilute it with water until degree. Mix well. This solution 1mL contains 1000µg silicon.

3.8 Boron standard storage solution

Weigh 0.5720g of spectral pure boric acid (H3BO3) dried at 40°C~45°C for 1h, and place it in 100mL stone

After dissolving in the English beaker, transfer it to a 100mL volumetric flask and dilute to the mark with water. Mix well. This solution 1mL contains 1000µg boron.

3.9 Chromium, iron, and boron mixed standard solution

Pipette 10.00mL chromium, iron, boron standard storage solution (3.5, 3.6, 3.8) into 100mL volume respectively

In the bottle, add 10mL hydrochloric acid (3.1), dilute to the mark with water. Mix well. This solution 1mL contains 100µg chromium, iron, boron.

3.10 Silicon standard solution

Pipette 10.00mL silicon standard stock solution (3.7) into a 100mL plastic volumetric flask, add 10mL hydrochloric acid (3.1), dilute to the mark with water. Mix well. This solution 1mL contains 100µg silicon.

3.11

Argon (volume fraction >= 99.99%).