Direct analysis of materials using direct sample insertion devices and mixed gas inductively coupled plasma atomic emission spectrometry

Abstract

It is shown that a direct sample insertion (DSI) device can be used in conjunction with inductively coupled plasma atomic emission spectrometry for the direct determination of trace elements in a variety of materials. The majority of analyses involving DSI devices have concerned samples in the form of small aqueous solution volumes or dried solution residues. Successful analyses have now been carried out for the direct insertion of Al₂O₃, Al metal, oil and botanical samples. The key operational feature that has allowed the successful direct determination of trace elements in these materials, with essentially no a priori sample treatment, is the utilization of an argon–oxygen mixed gas plasma. The calibration curves are linear over a dynamic range of 3–4 orders of magnitude and the detection limits are in the range of tens of picograms.