Atomic Spectrometry Update. Atomic mass spectrometry

Abstract

This Update follows the same format as last year's. Although an attempt is made to consider all relevant refereed papers, conference abstracts, reports, book chapters and patents for inclusion in this review, the content of the review is highly selective. The selection of papers is based on criteria applied to focus sharply on the most significant developments in instrumentation and methodology or improved understanding of the fundamental phenomena involved in the MS process. With the increasing importance of speciation and the blurring of boundaries between atomic and molecular MS, a high degree of judgement is required in considering papers for inclusion. The main ruling criterion for all speciation papers is that the work should involve or be intended for the study of natural systems. For example, the study of synthetic metal clusters is generally not included whereas the determination of organometallic compounds in environmental samples is.

Applications of atomic MS are not covered in this Update and readers are referred to the Updates on Industrial analysis: metals, chemicals and advanced materials, Environmental analysis and Clinical and biological materials, food and beverages. There have been few general reviews of note. That of Walczyk gave a good introduction to the use of inorganic MS in human nutrition research.

The trends noted over the last few years have continued. In particular, the growing interest in speciation studies has been reflected by the number of papers on the subject. As the number of species identified increases then the danger of relying solely on chromatographic retention times for identification has become a recurring warning in papers. For this reason, the importance of GDMS, ESMS and S-SIMS for species identification has been widely recognised. In all these studies, sample preparation and introduction have generally received most attention, with the aim of ever improved analysis. The increasing use of multicollector ICP-MS instruments for isotope geology studies has resulted in common ground with traditional TIMS methods, in particular in sample preparation.

Throughout this review, the term molecular ion will be restricted to denote only the positive or negative radical ion formed by removal or capture, respectively, of an electron. In contrast, addition of a proton or cation to a neutral molecule gives molecular adduct ions. Deprotonated molecules are considered as fragments.