Determination of Indium in High Arsenic Lead Soot by Inductively Coupled Plasma Atomic Emission Spectrometry

A method for determination of indium in high arsenic lead soot by inductively coupled plasma atomic emission spectrometry (ICP-AES) was proposed. 0.10-0.15 g of the sample was taken into a 250 mL-beaker, and a little water was added to moisten. 5 mL of hydrochloric acid was added and the mixture was digested at 200 ℃ on a electric heating plate for 2 min. 15 mL of nitric acid was added, and the mixture was concentrated to 10 mL on a 200 ℃ electric heating plate. 10 mL of 1.5 g·L⁻¹ chromium internal standard solution was added after the solution was cooled down. The sample solution was made its volume up to 200 mL with water. The emission intensity of indium was measured at 325.606 nm, and the emission intensity of chromium internal was measured at 267.716 nm. As shown by the results, linear relationship between the ratio of the corresponding emission intensity to the internal standard emission intensity and mass concentration of indium was found in the range of 5-40 mg·L⁻¹, with detection limit (3s) of 0.002 0%. RSDs (n=11) of the determined values of test for precision on four samples were less than 1.5%. Test for the spiked recovery was made on actual samples, giving results in the range of 99.2%-101%. The standard addition method was used for verification, and the detemined values were basically consistent with those from this method.