YS/T 630-2016Chemical analysis method of alumina - Determination of impurities in alumina - ICP-AES analytical method (English PDF)

4.6 Aluminum matrix solution (20 mg/mL). Weigh 5.2873 g of high-purity aluminum

(4.4) into a 1000 mL beaker; add 400 mL of sulfuric acid (4.3), place the beaker on an electric stove, and slowly heat until completely dissolved. Cool, transfer the solution to a 500 mL volumetric flask, dilute to the mark with water, mix thoroughly, and store in a polyethylene bottle. 1 mL of this solution contains 20 mg of aluminum oxide.

4.7 Standard storage solution

4.7.1 Prepare standard solutions of silicon, iron, sodium, potassium, copper, magnesium, calcium, chromium, vanadium, zinc, titanium, manganese, gallium, lithium, beryllium, and boron according to GB/T 602, with the concentrations of silicon, potassium, vanadium, and titanium at 100 µg/mL and those of iron, sodium, copper, magnesium, calcium, chromium, zinc, manganese, gallium, lithium, beryllium, and boron at 1000

µg/mL.

4.8 Mixed standard solution. Pipette 10.00 mL each of the iron and calcium standard solutions (4.7), 50.00 mL of the sodium standard solution (4.7), 5.00 mL each of the copper, magnesium, chromium, zinc, manganese, gallium, lithium, beryllium, and boron standard solutions (4.7), and 50.00 mL each of the vanadium and titanium standard solutions (4.7) into a 250 mL volumetric flask, dilute to the mark with water, mix thoroughly, and transfer to a polyethylene bottle for storage. This solution contains

40 µg/mL each of iron and calcium, 200 µg/mL of sodium, and 20 µg/mL each of copper, magnesium, chromium, vanadium, zinc, titanium, manganese, gallium, lithium, beryllium and boron.

7.1 Test specimen

Weigh 0.2 g of the sample (Chapter 6) to the nearest 0.0001 g.

7.2 Number of measurements

Two measurements shall be performed independently, and the average value shall be taken.

7.3 Blank test

A blank test shall be performed along with the specimen test.

7.4 Preparation of analytical solution

7.4.1 Place the specimen (7.1) in a polytetrafluoroethylene digestion vessel, add 12.0

mL of sulfuric acid (4.2), and digest in a microwave digester (5.3) until the sample is completely dissolved. Remove the digestion vessel, cool to room temperature, transfer the solution to a 100 mL volumetric flask, dilute to the mark with water, and mix thoroughly.

7.4.2 Place the specimen (7.1) in a polytetrafluoroethylene reaction cup, add 12.0 mL

of sulfuric acid (4.2), and cover tightly. Place the reaction cup in a sample dissolver and cover tightly. Heat the dissolver to 240 °C±2 °C in an oven, maintain for 6 hours, remove the dissolver, and allow it to cool naturally to room temperature. Remove the reaction cup, transfer the solution to a 100 mL volumetric flask, dilute to the mark with water, and mix thoroughly.

7.5 Preparation of standard series solutions

7.5.1 Pipette 0 mL, 1.00 mL, 3.00 mL, 5.00 mL, 8.00 mL, and 10.00 mL of the silicon standard solution (4.7) into a set of 100 mL volumetric flasks. Add 10.00 mL of the aluminum matrix solution (4.6) to each flask. Dilute to the mark with water, mix thoroughly, and store in polyethylene bottles.

7.5.2 Pipette 0 mL, 1.00 mL, 3.00 mL, 5.00 mL, 8.00 mL, and 10.00 mL of potassium standard solution (4.7) into a set of 100 mL volumetric flasks. Add 10.00 mL of aluminum matrix solution (4.6) to each flask. Dilute to the mark with water, mix well, and store in polyethylene bottles.

7.6 Determination

Under the selected instrument's optimal working conditions, measure the standard series solutions (7.5) and the analytical solution (7.4).