Atomic spectrometry update. Environmental analysis

Abstract

This is the 28^th annual review published in JAAS on the application of atomic spectrometry to the chemical analysis of environmental samples. This Update refers to papers published approximately between September 2011 and August 2012 and continues the series of Atomic Spectrometry Updates (ASUs) in Environmental Analysis¹ that should be read in conjunction with other related ASUs in the series, namely: clinical and biological materials, foods and beverages²; advances in atomic spectrometry and related techniques³; elemental speciation⁴; X-ray spectrometry⁵ and industrial analysis: metals, chemicals and advanced materials.⁶ In the field of air analysis there is ongoing interest in measuring atmospheric Hg species and evaluating procedures for the determination of the carbonaceous content of airborne particulate matter. Other noteworthy areas of interest include: development of LIBS and MS systems for in situ measurement; and the use of synchrotron-based X-ray techniques for the solid-state speciation of airborne particles. In the field of water analysis, as in previous years, the main areas of activity are the development, some may say redevelopment, of preconcentration and extraction procedures and elemental speciation protocols for elements such as As, Cr and Sb. There is increasing interest in developing portable instrumentation for field use using AES or XRF techniques. In the field of soil and plant analysis, noteworthy developments this year include the emergence of nanoSIMS as a tool for trace element imaging, and greater use of techniques such as LIBS and PXRF with chemometric data processing to provide overall identification or classification of samples, rather than accurate quantification of specific analytes. Of concern, however, is the publication of several articles ‘reinventing the wheel’. For example, one study compared the analysis of dust by PIXE with results obtained by ICP-AES following HNO₃ digestion according to USEPA Method 3050B, and another compared XRF data for soil samples with data from ICP-MS analysis of aqua regia soil digests. Unsurprisingly, both concluded that the X-ray technique produced higher concentrations for some elements than pseudo-total digestion! This suggests that there is a need for greater engagement between analytical and environmental geochemists to ensure that users of atomic spectrometry—and perhaps also some journal editors—are aware of the established scope of different analytical techniques and methods. Developments in geochemical analysis include: production and certification of new geological RMs with well-constrained isotopic contents or the recertification of existing RMs to include such isotopic data; optimisation of LA-ICP-MS and TIMS techniques and the reported use of a new ICP-MS instrument equipped with a Mattauch-Herzog type array detector to deliver improved isotopic measurement capabilities. Feedback on this review is most welcome and the lead author can be contacted using the email address provided.