GB/T 6609.1-2018Chemical analysis methods and determination of physical performance of alumina—Part 1: Determination of trace elements content—Inductively coupled plasma atomic emission spectrometry method (English PDF)

3.6 Alumina matrix solution (20 mg/mL)

3.6.1 Matrix Solution I. Weigh 5.288 g of aluminum (3.5) into a 1000 mL beaker. Cover with a watch glass. Add 300 mL of hydrochloric acid (3.2) in portions. After the violent reaction subsides, slowly heat until completely dissolved. Add a few drops of hydrogen peroxide (rho = 1.10 g/mL). Boil for several minutes. Cool. Transfer the solution to a 500 mL volumetric flask. Dilute to the mark with water. Shake well. Store in a polyethylene bottle.

3.6.2 Matrix Solution II. Weigh 5.288 g of aluminum (3.5) into a 1000 mL beaker. Cover with a watch glass. Add 330 mL of sulfuric acid (3.1) in portions. Slowly heat until completely dissolved. Cool. Transfer the solution to a 500 mL volumetric flask. Dilute to the mark with water. Shake well. Store in a polyethylene bottle.

6.1 Test material

Weigh the specimens (5) according to Table 2 to the nearest 0.0001 g.

6.2 Number of determinations

The determinations are performed twice independently. Take the average value.

6.3 Blank test

Carry out a blank test along with the test material (6.1).

6.4 Preparation of analytical solution

6.4.1 Sample dissolution method I

Weigh the test material (6.1) according to Table 2 and place it in a 100 mL polytetrafluoroethylene reaction cup. Add 10 mL of hydrochloric acid (3.4). Cover the polytetrafluoroethylene reaction cup. Place in a polytetrafluoroethylene sealed sample dissolver (4.3). Place in an oven (4.4). Insulate at 240°C ± 3°C for 5 h. Remove. Cool to room temperature. Transfer the solution to a volumetric flask of the corresponding volume as shown in Table 2. Rinse the reaction cup with water. Combine the wash solution in the volumetric flask. Dilute to the mark with water. Mix thoroughly.

6.4.2 Sample dissolution method II

Weigh the test material (6.1) according to Table 2 and place it in a 100 mL microwave digestion reaction cup. Add 10 mL of sulfuric acid (3.3). Cover the reaction cup lid and place it in the microwave digestion apparatus. Dissolve under the selected microwave digestion optimal measurement procedure. After the test material is completely dissolved, cool it to room temperature. Transfer into a 100 mL volumetric flask. Wash the reaction cup with water. Wash the liquid into a volumetric flask. Dilute with water to the mark. Mix well. This method is not applicable for the determination of CaO content.

6.5 Preparation of series standard solutions

6.5.1 Sample dissolution method I

According to the amount of alumina in the test solution, transfer an appropriate amount of aluminum matrix solution (3.6.1) into a set of 100 mL volumetric flasks, so that the amount of alumina in the standard solution is basically the same as that in the test solution. According to the mass fraction of each element in the sample, add an appropriate amount of standard solution (3.8.1) or (3.8.2) of the element to be tested, so that the type and acidity of the acid in the standard solution are basically the same as those in the test solution. Dilute with water to the mark. Mix well. Store in polyethylene bottles. Use the test solution without standard solution as the blank solution, so that the content of the tested element should be within the range of the working curve. The number of standard solutions in the series shall not be less than 5. The mass fractions of each element should be distributed as evenly as possible.

6.5.2 Sample dissolution method II

According to the amount of alumina in the test solution, transfer an appropriate amount of aluminum matrix solution (3.6.2) into a set of 100 mL volumetric flasks, so that the amount of alumina in the standard solution is basically the same as that in the test solution. According to the mass fraction of each element in the sample, add an appropriate amount of standard solution (3.8.1) or (3.8.2) of the element to be tested, so that the type and acidity of the acid in the standard solution are basically the same as those in the test solution. Dilute with water to the mark. Mix well and store in a polyethylene bottle. Use the test solution without standard solution as the blank solution, […]