Atomic mass spectrometry

The format of this year's Update follows that used in last year's(1) with s ome minor changes in the section headings. Although an attempt is made to c onsider all relevant refereed papers, conference abstracts, reports, book c hapters and patents for inclusion, this review does not aim at being compre hensive in its coverage. The selection of papers is based on criteria appli ed to focus sharply on the most significant developments reported during th e period (approximately corresponding to 1998) covered by this Update. The prime consideration is that the reports should present advances in instrume ntation and methodology or improved understanding of the fundamental phenom ena involved in the MS process. As a general rule, conference abstracts are not included because they rarely provide sufficient information to judge w hether or not they meet the criteria. We consider it better to wait for ful l details to appear in a refereed journal. A similar policy applies to thos e papers in a language other than English and unlikely to reach a wide read ership. Routine applications of atomic MS are not covered in this Update and reader s are referred to the Updates on Industrial analysis: metals, chemicals and advanced materials,(2) Environmental analysis(3) and Clinical and biologic al materials, food and beverages.(4) A book that can be thoroughly recommen ded is that edited by Gill(5) on Modern Analytical Geochemistry. Chapters o n most of the techniques included in this Update gave full yet concise desc riptions of the underlying principles of the techniques, with examples of a pplications in geochemistry and environmental science. The substantial revi ew (269 references) of Becker and Dietze(6) covered in detail the inorganic MS techniques that are used for inorganic trace analysis. This Update follows the policy set by JAAS in deciding the scope of papers which can be considered for inclusion. With the increased use of atomic spe ctroscopy techniques, in particular MS, in speciation studies the scope has been widened to include not only elemental but also speciation studies, in cluding those in which molecular species are determined as long as the focu s of the study is the element and its chemical form. With the boundaries be tween atomic and molecular MS becoming less well defined, the judgement of the authors of this Update becomes important in achieving a correct balance . In general, studies of unstable nuclei are excluded but the determination of radioactive elements in 'real' samples are included. The trends apparent for the various MS techniques are highlighted in the ap propriate sections. In general, more attention continues to be paid to samp le preparation and introduction rather than instrumentation. A common featu re for many of the techniques reviewed is the need for analysis of smaller samples. This has presented challenges of reducing the levels of contaminat ion and background noise and also calibration and standardization. The use of ICP-MS for the measurement of isotope ratios is noted as an increasingly important application.