8: Vapour Generation and Atomic Fluorescence Spectrometry Check Access

This chapter covers both vapour generation and atomic fluorescence because they are often coupled together as a means of sample introduction and detection. The advantages and disadvantages of vapour generation as a means of sample introduction are presented indicating where serious errors can be obtained if an unwary analyst makes too many assumptions. The advantage of improved sensitivity that is obtained is offset by the fact that not all oxidation states of an analyte form a vapour and not all analytes form vapours. Care must therefore be taken to ensure that all species of an analyte have been transformed to the same, “reducible” form prior to analysis. Methods for ensuring this are presented. Coupling with AAS, AFS and ICP instruments is all possible, and the pitfalls of each are discussed. A hints and tips section discusses how to overcome chemical interferences and how to prevent excess frothing in the gas–liquid separator from causing a problem. The final section discusses atomic fluorescence along with its advantages and disadvantages.