Quantitative determination of trace metals in high-purity silicon carbide powder by laser ablation inductively coupled plasma mass spectrometry without binders

摘要

We have developed a laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) method to directly determine the concentrations of trace metals in high-purity powdery silicon carbide (SiC) samples. The sample preparation procedure is simple and rapid. The sample was formed into pellets using no binders and heated at 1000 °C for 2 h. The operation parameters for LA and ICP-MS were optimized to achieve a table signal intensity and high sensitivity. National Institute of Standards and Technology Standard Reference Materials glasses were chosen as calibration standards, with ~(29)Si chosen as the internal standard. The relative sensitivity factor obtained from the glass matrix was used to calculate the concentrations of analytes in the SiC ceramic samples. The regression correlation coefficients of the calibration curves for elements with internal standard correction ranged from 0.9981 to 0.9999, which are better than those obtained with an external standard correction method only. The relative standard deviation of the measured trace element concentrations was less than 5%. The limits of detection were 0.02, 0.08, 0.04,0.005, 0.01,0.02,0.004,0.07, and 0.006 mg kg~(-1) for B, Ti, Cr, Mn, Fe, Ni, Co, Cu, and Sr, respectively. The method was applied to analyze SiC samples with two different particle sizes. The analysis showed good agreement with the results of inductively coupled plasma optical emission spectrometry. The reliability of the proposed method was confirmed by determining the contents of B, Ti, Cr, Mn, Fe, Ni, and Cu in BAM-S003.