Speciation of silicon and phosphorous using liquid chromatography coupled with sector field high resolution ICP-MS

Abstract Sector-field high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) has been used, at R =3000, to resolve spectral interferences caused by N 2 + and CO + on 28 Si + , and NOH + and NO + on 31 P + , thereby facilitating the speciation of these elements. Polydimethylsiloxanes (PDMS), ranging from 162 g mol −1 to 16 500 g mol −1 , and their silanol breakdown products, have been separated by size exclusion and reverse phase chromatography, respectively, and detected using HR-ICP-MS. Detection limits (as Si) of between 12–30 ng ml −1 and 0.1–4 ng ml −1 were obtained for the PDMS and silanol compounds, respectively. Quantitative and reproducible methods have been developed for the analysis of four common organophosphorous pesticides in blood plasma, and inorganic phosphates in food, with detection limits of between 0.9–2 ng ml −1 and 1–39 ng ml −1, respectively.