Flow Injection and Atomic Absorption Spectrometry (FI-AAS) -

Elo Harald Hansen

Research output: Contribution to journalJournal articleResearch

Abstract

One of the advantages of the flow injection (FI) concept is that it is compatible with virtually all detection techniques. Being a versatile vehicle for enhancing the performance of the individual detection devices, the most spectacular results have possibly been obtained in conjunction with atomic absorption spectrometry (AAS). Initially with flame-AAS (fAAS) procedures, later for hydride generation (HG) techniques, and most recently in combination with electrothermal AAS (ETAAS). The common denominator for all these procedures is the inherently precise and strictly reproducible timing in FI from the point of sample injection/introduction to the point of detection. Hence, in FI-fAAS this feature allows not only to obtain improved repeatability but also improved accuracy, and because the wash to sample ratio is high it permits the handling of samples with elevated salt contents - which in conventional operation readily might lead to clugging of the burner. In FI-HG procedures it entails several advantages: Thus, via the generation of the gaseous hydride the analyte is effectively separated from the constituents of the matrix material. Furthermore, the rigorous and exact timing of FI in many instances makes it possible to exploit kinetic discrimination towards species which by their presence potentially might interfere in the hydride generation process or act as mediators for the degradation of the hydrides formed. And not the least, the FI-HG approach opens entirely new avenues for performing suitable on-line sample pretreatment and preconcentration procedures prior to the hydride generation process itself. In FI-ETAAS - which only recently has been explored at any appreciable extent - it promises to yield new and exciting possibilities for determining ultra-low concentrations of a number of (especially HG- forming) elements. In the words of the one of the authorities of AAS and foremost pioneers of FI-AAS - Professor Z. L. Fang, who is the author on two recently published monographs on this hyphenated technique - the impact of FI on AAS is "so dramatic" that it has brought "new vitality to a technique [AAS] which otherwise seemed to be confronted by a period of stagnancy". The communication demonstrates, by several practical examples, especially selected from works conducted in the author's own group, this new vitality.
Original languageDanish
Journaldansk kemi
Volume77
Issue number9
Pages (from-to)18-23
Publication statusPublished - 1996
EventThe 15th Nordic Atomic Spectroscopy and Trace Element Conference - Ebeltoft, Denmark
Duration: 2 Jun 19966 Jun 1996

Conference

ConferenceThe 15th Nordic Atomic Spectroscopy and Trace Element Conference
Country/TerritoryDenmark
CityEbeltoft
Period02/06/199606/06/1996

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