Sample processing: Accurately weigh 0.5g of the sample and place it in a microwave digestion tank. Add 6mL of nitric acid, 3mL of hydrofluoric acid, and 1mL of hydrochloric acid. After microwave digestion, transfer to a volumetric flask and add 10mL of 20%. At the same time, make a sample blank. In addition, a 0.2.4.8.10ppm calibration solution is configured, with a standard solution maintained at 2% and 1% nitric acid.