Vapour generation atomic fluorescence

More recently, PS Analytical have introduced the PS A 10.003 and the Merlin Plus continuous flow vapour generation atomic absorption and atomic fluorescence spectrometers (AFS) [10-12]. These facilitate the determination of very low concentrations (ppt) of mercury, arsenic, and selenium in solution, enabling amounts down to 10-20 ppm of these elements to be determined in polymer digests. 

Atomic Fluorescence System - Millennium Excalibur PSA 10.055 -was used in our work. This system consists of the autosampler, the integrated continuous flow vapour generator and the atomic fluorescence spectrometer with the boosted dischar ge hollow cathode lamp and a control computer. 

Atomic fluorescence coupled to cold vapour generation. 

Hutton, R.C. and Preston, B. (1980) A simple non-dispersive atomic-fluorescence spectrometer for mercury determination, using cold-vapour generation. Analyst, 105, 981-984. 

Atomic fluorescence has the advantage of being less prone to spectral interferences than either AES or AAS. Molecular fluorescence is less of a problem than molecular absorption is in AAS. Scatter from the light source and quenching from the gaseous species in the atom cell are often the major sources of interference. For many applications where the analyte is separated from the matrix (e.g. vapour generation) chemical interferences may exist for example, the presence of high concentrations of some transition metals may interfere in the hydride formation process. This will inevitably lead to errors in the measurement unless preventative steps are taken. 

Table 4.1 [37-43] shows the figures of merit of typical hydride generation and cold mercury vapour formation methods using atomic absorption or fluorescence detection. 

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