Matrix interferences from methacrylic acid solutions in inductively coupled plasma mass spectrometry

Abstract

It was found that substantial interference effects were present, which dramatically reduced sensitivity in the determination, by inductively coupled plasma mass spectrometry, of trace elements in methacrylic acid solution. Mass bias effects were observed, which led to either enhancement or suppression of analyte signals, depending on the conditions used and the concentration of methacrylic acid present in solution (1–10% m/v). An instrumental procedure based on optimizing plasma conditions and spectrometer ion optics settings was found to reduce significantly the magnitude of the interference effect. However, the use of aqueous calibration standards still gave rise to errors (changes in slope of 1–18% in the presence of 5% m/v methacrylic acid), which could not be corrected for by the use of internal standards when using compromise multi-element analysis conditions. The use of the standard additions method, under conditions optimized for the matrix, is proposed to avoid such calibration problems.