Determination of trace acid soluble aluminium in steel by inductively coupled plasma mass spectrometry

Abstract

The sample was dissolved with nitric acid. A determination method of trace acid soluble aluminum (Als) in steel by inductively coupled plasma mass spectrometry (ICP-MS) was established. The determination conditions were also optimized. The experiment showed that the use of purified nitric acid to dissolve sample could reduce the influence on determination results. The matrix effect of high-purity iron could not be ignored, so the calibration curve was prepared by standard addition method with testing sample as matrix to eliminate this effect. The sample was dissolved in quartz beaker, and the determination results were more stable than those conducted in glass beaker. The sample solution of silicon steel certified reference material was diluted to constant volume in plastic volumetric flask, and the determination result was closer to the certified value than that in glass volumetric flask. The sample pretreatment conditions were optimized: the amount of nitric acid was 5 mL and the dissolution time was 10 min. The determination results of silicon steel certified reference material with 45Sc as internal standard was closer to the certified value than that with 89Y. When the pipe was washed with 2% (volume fraction) nitric acid for 8 s, the memory effect could be basically eliminated. The mass concentration of 27Al was used as x-axis, while the response ratio of 27Al to internal standard element was used as y-axis to prepare calibration curve by standard addition method. The correlation coefficient of calibration curve equation was 0.999 8. The low limit of determination for the method was 0.000 06%. The proposed method was applied for determination of five certified reference materials of steel and two actual samples of alloy steel. The results were basically consistent with the certified values. The relative standard deviations (RSD, n=5) were between 1.6% and 4.5%.