Determination of Silicon,Iron,Molybdenum,Potassium and Sodium in Vanadyl Oxalate by ICP-OES

The analyzing method directly and simultaneously detecting silicon（Si）,iron（Fe）,molybdenum（Mo）,potassium（K） and sodium（Na） with the content of 0.001%~0.100% in vanadyl oxalate（VOC₂O₄） using inductively coupled plasma atomic emission spectrometry（ICP-OES） was established.The influences of matrix effects,spectral interferences and continuous background superposition in the system with high concentrations of vanadium ion and oxalate coexistence,on the testing were studied,and the conclusions that the matrix effects and continuous background superposition of VOC₂O₄ have a negative interference to K and Na but a positive disturbance to Si,Fe and Mo in the system were obtained.Matrix matching coupled with synchronous background correction was employed to eliminate the matrix effects of VOC₂O₄.Based on the spectral interference from matrix elements vanadium（V） and carbon（C）,the candidates of spectral lines disturbed by the spectra of matrix components were selected,from which the appropriate analyzing spectral lines,background correction areas and operation conditions of spectrometer for the tested elements were determined.The results show that the RSD is less than 10% with-0.000 3%~0.000 3% of background equivalent concentration,0.000 1% ~0.000 3%（0.005~0.015 mg/L） of element detection limit and 0.001%~0.010% of element content,while the RSD is less than 5% with 0.010% ~0.050% of element content.The recovery rate is 91.6% ~109.4%,and the testing results are in accordance with those by ICP-MS.