Atomic spectrometry update – a review of advances in environmental analysis

Abstract

Highlights in the field of air analysis included: a new focus on measuring tyre-wear particle emissions; an interest in using unmanned aerial vehicles for sampling purposes and an increased use of ICP-MS for measuring halogenated volatile organics, metals sampled directly from air and single particles. Workers have explored further the full capabilities of ICP-MS/MS, which continued to dominate water analysis, including the speciation analysis of non-metallic elements in environmental samples. By far the largest number of papers on water analysis involved preconcentration. The growing interest in reagents for green chemistry was evidenced by the publication of several reviews. Novelties included the direct introduction of magnetic nanoparticles into FAAS to boost sensitivity, and the simultaneous dual-drop preconcentration of oxidation state species that avoided the need for a sequence of elution steps by preconcentrating the analytes into specific reagents contained in the drops. Although the total reflection XRFS and LIBS techniques are close to achieving the detection limits needed to screen contaminated waters, users of these instruments often neglect to validate their methods adequately through the use of reference materials. In methods for the analysis of soils, plants and related materials, sustainable digestion, extraction and preconcentration methods featured strongly. The development of AAS, AES and AFS methods for the direct analysis of solid samples and for increasing sensitivity through analyte enrichment continued to be of considerable interest. The nitrogen-microwave inductively coupled atmospheric-pressure plasma showed promise for ICP-MS analyses. Applications of LIBS have increased dramatically in number with noteworthy developments including single-chamber laser-ablation LIBS and the analysis of plant leaves without the need for grinding and pelleting. However, many published studies lacked validation through e.g. analysis of CRMs or comparison with results obtained by other techniques. Efforts have continued on the characterisation of natural and synthetic materials that are sufficiently homogeneous to act as reference materials (RMs) in the analysis of geological materials. In particular, application of microanalytical techniques, such as LA-ICP-MS and SIMS, led to the availability of a variety of new RMs for in situ isotope ratio determinations. The application of portable LIBS instrumentation to mineral prospecting and ore processing has received much attention, with the development of new chemometric models to improve data quality. The enormous amount of analytical data produced by modern instrumentation prompted the development of software, most of which has been made freely available, for facilitating the processing and reduction of isotopic data.