USE OF A FURNACE WITH A GRAPHITE FILTER FOR ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY

The development of an atomization technique for electrothermal atomic absorption spectrometric (ETAAS) analysis, based on the filtration of the analyte vapour through heated graphite, is presented in its histor ical context. Initially the method was applied to the analysis of soli ds. Despite the effectiveness of atomization, the time taken to prepar e each solid sample and graphite tube arrangement made single-element determinations impractical using the ETAAS technique. The proposed new version of the furnace with a graphite filter was designed for the an alysis of liquids using commercial ETAAS instruments equipped with an autosampler, programmable power supply and a system for background cor rection. The main advantages of the atomizer were discovered in the co urse of the determination of Al, Bi, Cd and Cu for different sample vo lumes, and Cd, Pb and Bi in the presence of NaCl and CuCl2 matrices. T hese advantages include: a 1.6-2.8-fold increase in sensitivity; the p ossibility of increasing the volume of doped solutions up to 100 mul, and at-the same time reducing the drying period to 15 s; and obtainmen t of a lower level of spectral background and chemical interferences w ithout chemical modification. The accuracy of the method was verified by the determination of Cd and Pb in whole blood and steel.