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Practical implementation of survey analysis in inductively coupled plasma optical emission spectrometry

1998; Elsevier BV; Volume: 53; Issue: 5 Linguagem: Inglês

10.1016/s0584-8547(98)00117-7

1873-3565

J. Moralès, E.H. van Veen, M.T.C. de Loos-Vollebregt,

Analytical Chemistry and Sensors

The combination of an echelle/charge coupled device detector based spectrometer with software for multicomponent analysis (MCA) allows practical implementation of survey analysis in inductively coupled plasma-optical emission spectrometry (ICP-OES). MCA requires models for the pure components. A procedure is described for how to obtain the models for 67 pure elements detectable in ICP-OES. In fact, each element is represented by two model vectors. Measurements at low analyte concentration provide the sensitivities for the prominent lines used in trace analysis, whereas weak lines and continuum emission are modelled with high concentration measurements. This modelling allows proper calibration for trace and major levels, and strongly reduces noise contributions. The model library is prepared once and a monitor solution, containing seven specific elements, is used to achieve a daily link with this once-only calibration (wavelength axis and sensitivity). To control the efficiency of atomization and ionization the Cr ii 267 nm to Cr i 357 nm ratio is used. The MCA calculations are repeated at different intensity levels in order to cover the dynamic range in intensity and, hence, concentration for all the elements present in the sample solution. Matrix-matching of the monitor solution was studied in order to overcome matrix effects owing to high acid or salt contents. Some certified reference materials were analysed. The results for most elements are found within 20% of the certified values.