Analytica Chimica Acta 291(1994) 127-136 Graphite furnace hydride preconcentration and subsequent detection by inductively coupled plasma mass spectrometry Isam Marawi, Jiansheng Wang, Joseph A. Caruso * zyxwvutsrqponmlkjihgfedc Department of Chemktv, University of Cincinnati, Cincinnati, OH 45221-0172, USA (Received 18th October 1993; revised manuscript received 5th January 1994) Abstract Preconcentration of multi-element volatile hydrides in a graphite furnace and the subsequent determination by inductively coupled plasma mass spectrometry (ICP-MS) is a relatively new method for elemental analysis. This method offers several advantages over direct hydride generation sample introduction. In this technique the excess hydrogen generated as a by-product of the reduction reaction of the analytes was not introduced into the plasma with the analytes, thus giving the plasma greater stability. The hydrides of arsenic, bismuth, and tellurium were trapped in the presence of metallic palladium inside the graphite tube of an electrothermal vaporization unit, and subsequently determined by the ICP-MS in a single run. The linearity obtained using this method was limited to a sub-ng/ ml concentration range. The preliminary limit of detection calculated for arsenic is 0.002 ng ml - I, this value was based on the slope value of the linear portion of the calibration curve. Effectiveness of the trapping method was determined by analysis of a standard reference material. Key words: Inductively coupled plasma mass spectrometry; ETV graphite furnace; Hydride preconcentration; Pre- concentration zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA 1. Introduction One advantage of hydride generation is the ability to preconcentrate the analytes before they In recent years, the demand to find lower reach the atomizer. The method most often used limits of detection for elements with environmen- for hydride preconcentration is the cold trapping tal significance has been greater than ever before. technique, which was first introduced by Holak Several elements which are considered an envi- [6]. In this method the volatile products of the ronmental hazard, and which can form volatile hydride generation reaction are purged through a hydrides include As, Sn, Pb, Bi, Se and Te. The liquid nitrogen trap. The hydride analyte con- advantages of the hydride generation technique denses inside the trap while the hydrogen by- for sample introduction in atomic spectrometry product vents. After the reaction is complete the have been described in several reviews [l-5]. trap is removed from the liquid nitrogen and heated rapidly to revolatilize the hydride. An argon purge carries the hydride from the trap * Corresponding author. into the atomizer. The rapid volatilization of the 0003-2670/94/$07.00 8 1994 Elsevier Science B.V. All rights reserved SsDIOOO3-2670(94)00030-P