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

Abstract

This ASU reviews publications that appeared in the twelve months up to the end of October 2002. The writers found there to be an interesting collection of publications and enjoyed the opportunity to review current analytical activity for clinical and biological materials, foods and beverages. It was noted that Chinese-based scientists are responsible for much of the innovations that we have reported in this Update. This year has seen tremendous growth in the employment of permanent chemical modifiers for electrothermal atomisers. Rhodium was introduced for the measurement of selenium, just a couple of years ago, and now it is looking as if it may displace palladium as the modifier of choice for this and many other determinations. The writers were impressed by an unusual device that produced a dry ‘aerosol’, allowing the transfer of solid powdered material into a quartz tube mounted above a flame burner head. As the sample had to be reduced in size to a very fine powder it is unlikely that the technique will gain widespread popularity but the idea in principle appears very clever. Similarly, the use of ICP-mass spectrometry as a measurement technique for immunoassay, while novel, does not appear to be very practical when an assay can involve several hundred measurements. A number of intriguing papers were noted. We were impressed by the subjects who participated in studies of dermal penetration of nickel compounds—these individuals had sticky tape placed on the skin, which was then pulled off together with underlying cells; this procedure was then repeated up to 20 times. We pondered over a method that involved formation of SeH₂, which was oxidised to Se⁰ and trapped on a hot gold wire. After a trapping period of up to 5 min the Se⁰ was released for hydride formation and measurement. The English expression “takes the biscuit” came to mind as we puzzled with an even more remarkable report of the measurement of iron and manganese in biscuits by a cold vapour technique! After which, the revelation that camels’ milk is an ideal nutrient caused barely a second thought.