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Three techniques for studying spatial emission from sources used in analytical atomic spectrometry are described. Photographic evaluation using digitisation by (i) a microdensitometer with a computerised interface and (ii) a television camera digitiser, were compared with computerised tomography using a filtered back projection algorithm. The photographic methods were used to study a direct current plasma and although useful information on plasma structure could be obtained, details of the internal structure were obscured as the images presented the sum of the signal in the direction viewed. There were also limitations to quantification of data. A tomographic system using a self-scanning linear photodiode array interfaced to a laboratory computer is described which should overcome these limitations. The application of this system is illustrated using a laminar flow air-acetylene flame.

An interface is described for high-performance liquid chromatography-flame atomic absorption spectrometry. The system utilises the increase in sensitivity achieved by eliminating the nebulisation stage and by modifying the atom cell to incorporate an in flame tube atom trap. The effluent from the high-performance liquid chromatograph is collected as discrete aliquots on a series of rotating platinum spirals, which are then transported directly to a de-solvating flame and then to the atomising flame. The spirals are rotated by a stepper motor which is under microprocessor control. The factors affecting analytical performance, e.g., design of the spirals, positioning, timing, loading, flow-rates and de-solvation, were investigated and optimised. The analysis of mixtures of organolead compounds is used to demonstrate the effectiveness of the interface, particularly in terms of sensitivity, resolution and reproducibility. The system is shown to be sensitive, reproducible (less than 8% r.s.d.) and operates in real time with no loss of sample.

A computer controlled interface system is described for directly coupled high-performance liquid chromatography-flame atomic absorption spectrometry (HPLC-FAAS). The eluent from the HPLC is collected on a series of 20 rotating platinum spirals, desolvated by an electrically heated furnace and finally transported into an atomising air-acetylene flame. The spirals are rotated by a stepper motor (1.8° step angle) which is controlled by a microcomputer. The transient atomic absorption signal for each spiral is fed to the analogue to digital converter of the computer, via a simple interface, for data display and manipulation. The sensitivity of the interface was found to be about two orders of magnitude better than for conventional FAAS using nebulisation, detection limits for Cd, Hg, Pb and Zn were in the low nanogram to picogram range. The factors affecting the sensitivity and precision are reported. The interface was evaluated for the speciation of mercury compounds. Detection limits for Hg2+, CH3Hg+ and C6H5Hg+ were 3.5, 1.9 and 2.5 ng (as Hg), respectively. At the 40-ng level the mean relative standard deviation was 7%.

Revue detaillee de 100 references classees par methodes couplees (chromatographie en phase liquide couplee a spectrometrie d'absorption atomique de flamme, a atomisation electrothermique, spectrometrie de fluorescence atomique de flamme, spectrometrie d'emission optique) presentee sous forme de tableaux avec des details sur le detecteur, la methode, l'echantillon, des commentaires, l'element analysee

A simple yet effective high-performance liquid chromatography-flame atomic-absorption spectrometry coupling utilising pulse nebulisation and a slotted tube atom trap is described for the speciation of tin in natural waters. The effects of the various parameters on analytical performance are discussed. A detection limit of 200 ng for tin was obtained and the separation of Sn(II), Sn(IV) and tributyltin was possible within 8 min. Tributyltin compounds have been quantified in local harbour waters, and in one harbour situation were observed at levels up to 0.47 µg l–1.