HIGH-PERFORMANCE FLOW ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY FOR ONLINE TRACE-ELEMENT PRECONCENTRATION-MATRIX SEPARATION AND TRACE-ELEMENT DETERMINATION

With the aerosol deposition module (ADM) the samples to be analysed by electrothermal atomic absorption spectrometry (ETAAS) are carried as an aerosol into the graphite tube and deposited at about 140-degrees-C. The ADM is normally equipped with a pneumatic nebulizer, but in this work this is replaced by a hydraulic high-pressure (HHP) nebulizer. If HHP nebulization is used to produce the aerosol, the efficiency of aerosol transport is substantially improved (maximum aerosol yield, 60%). As a high-pressure flow system is required for this type of nebulization, on-line matrix separations-trace element preconcentrations for ETAAS are also possible. The trace elements can be separated on-line from aluminium solutions (AlCl3) and determined in 4 min. Detection limits are in the ng g-1 range (as trace elements in the aluminium). In comparison with the original ADM for sample introduction, the detection power is improved by about two orders of magnitude.