WeO-01 PLENARY

ATOMIC MASS SPECTROMETRY: THE NEXT GENERATION

Thomas W. Burgoyne, David M. Chambers***, Mark A. Heintz#, Gary M. Hieftje, Gangqiang Li##, Patrick P. Mahoney, David P. Myers*, Steven J. Ray and Barbara S. Ross-Buckley**

Department of Chemistry, Indiana University, Bloomington, IN 47405

#EOHSI, 681 Frelinghuysen Road, P.O. Box 1179, Piscataway, NJ 08855-1179

##Hewlett Packard, Palo Alto, CA

*Leco Corporation, 3000 Lakeview Avenue, St. Joseph, MI 49085-2396

**509 New York Boulevard, Sea Girt, NJ 08750

***Lawrence Livermore Laboratory, Chemical Forensic Center L-371, Livermore, CA 94550

Atomic mass spectrometry, usually implemented as inductively coupled plasma (ICP)-mass spectrometry, has become a dominant force in qualitative and quantitative elemental analysis. The technique provides rapid sample analysis, extremely low detection limits, broad elemental and isotopic coverage, moderate precision, minimal levels of spectral interferences (isobaric overlaps) and matrix interferences, simplicity of operation, broad dynamic range, and excellent performance in a semi-quantitative mode. However, the technique is not without its limitations. The most serious of these shortcomings include a residual susceptibility to interelement interferences (matrix effects), a few isobaric overlaps that can be devastating in the analysis of particular kinds of samples, precision that is ordinarily no better than 5% r.s.d., an analysis speed that is limited by the need to scan the desired elements or isotopes sequentially, and problems that occur when a transient or microsample must be analyzed.

In this presentation, the origins of several of these limitations will be discussed and ways to overcome them outlined. Greatest emphasis will be placed on the use of modified ion optics to eliminate matrix interference effects and the use of a time-of-flight (TOF) mass analyzer to improve precision, increase analysis speed, and make the technique more readily amenable to micro and transient samples.

With modified ion optics and a TOF mass analyzer, it is now possible to achieve precision levcls that are limited only by counting statistics and to analyze sample vapor produced by a single laser-ablation event. Furthermore, with such instrumentation, it is possible to achieve detection limits of less than one part per trillion in solution for virtually every element and isotope, and in a total sample-analysis time of 10 seconds or less. As importantly, mass resolving power during such determinations can be as high as 2300.

The impact of these developments on several areas of application of atomic mass spectrometry will be briefly discussed and evaluated.