COMPUTERIZED DATA TREATMENT FOR AN HPLC-GFAAS SYSTEM FOR THE IDENTIFICATION AND QUANTIFICATION OF TRACE-ELEMENT COMPOUNDS

Liquid chromatographs, coupled with graphite furnace atomic absorption spectrometers, have been widely used for the identification and quant ification of trace element compounds. The quantification of the discon tinuous signals from the spectrometer defining a chromatographic band is very much a matter of judgement and therefore prone to error. This paper describes a system which links a high-performance liquid chromat ograph via a 'Brinckman' flow-through cup to a Hitachi Zeeman graphite furnace atomic absorption spectrometer equipped with an autosampler. The introduction of aliquots from the column effluent and the analysis sequence is computer-controlled through a home-built interface. The s ignals from the spectrometer are passed through an analogue-digital co nverter and processed by selectable algorithms. The software offers a variety of options for processing the chromatographic data, such as da ta smoothing, Gaussian or spline interpolation, and trapezium or Simps on integration. This system was used to separate and determine selenit e and selenate in aqueous solution with absolute detection limits (3 s igma) of 23 ng Se for selenite and 16 ng Se for selenate. This system can be adapted to other spectrometers, provided that the required conn ections to the electronics can be made.