Interface system for directly coupled high-performance liquid chromatography-flame atomic absorption spectrometry

Abstract

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.