Atomic spectrometry update. Clinical and biological materials, foods and beverages

Abstract

The literature reviewed this year has included a larger than usual number of interesting reports. The use of ultrasonication to extract analytes from samples is increasing and a review article on this technique has been published. Similarly, solid-phase micro-extraction now has an accepted place within atomic mass spectrometry. Using what appear to be mini-Chinese lanterns, powdered liver in small paper capsules was inserted into a flame-heated quartz cell for measurement of Cd by AAS. Novel designs of electrothermal atomisers made an appearance with a two-step atomiser (to preconcentrate and determine Hg in urine and drinking water) and a filter atomiser (which reduced background absorbance when measuring Cd and Pb in blood). More clinical applications involving collision cell technology for ICP-MS are being reported. However, the most interesting work this year has been made possible with multiple collector ICP-MS. This technique has uncovered the phenomenon of isotopic fractionation, whereby the body absorbs or incorporates into tissues one isotope of an element more than another. A sober reflection on the plethora of Se species reported in recent years suggests that much of the published work may not be very useful. Of the 16 Se species described in urine it is suggested that several had been mis-identified, and that selenosugars are probably more important than the trimethylselenonium ion. Exposure to As in drinking water in Bangladesh rumbles on with the discovery of high concentrations in wells that were purported to have been fitted with filtering devices. Also in drinking water was the unlikely discovery of As compounds that can be derived from chemical warfare agents. A number of residents of the affected area in Japan displayed uncommon central nervous system symptoms which could be attributed to these As compounds. Among the interesting forensic work reported, laser ablation-ICP-MS was seen to provide the opportunity to examine hair samples with greater chronological resolution than other techniques, a case of thallium poisoning was detected decades after the victim died, and an insight into the social history of Turkey in the 4–6th centuries AD was afforded by the analysis of goat bones!