Determination of cadmium in certified reference materials using solid sampling electrothermal vaporization inductively coupled plasma mass spectrometry supplemented with thermogravimetric studies

The present study describes the application of solid sampling electrothermal vaporization inductively coupled plasma mass spectrometry (SS-ETV-ICP-MS) for the direct determination of Cd in five certified reference materials of plant, soil, and sediment origin The work incorporates the optimization of the most important instrumental parameters (furnace heating program, carrier gas Bow rate, plasma forward power) and notes significant differences in signal response behavior of samples of different origin, The applicability of thermogravimetry (TG) coupled to mass spectrometry for the optimization of SS-ETV-ICP-MS was also evaluated. TG information and data were thoroughly exploited in every phase of the study. Figures of merit, such as absolute limits of detection (0.2-0.5 pg Cd in 1 mg sample). sensitivities (0.45-2.0 10(5)/ng Cd), and precision (5-10% relative standard deviation), were also assessed. Three methods of standardization, including solid calibration using certified reference materials, generalized simplified standard addition, and multiple standard addition, were tested. our of which the method of multiple standard addition was found to be the most practical and reliable. (C) 1996 Academic Press, Inc.