Simultaneous determination of A, Cd, Cr and Pb in aqua regia digests of soils and sediments using electrothermal atomic absorption spectrometry and fast furnace programs

摘要

A method was developed for the simultaneous multi-element determination of As, Cd, Cr and Pb in aqua regia digests of soils and sediments using an electrothermal atomic absorption spectrometer with a transversely heated graphite atomizer and longitudinal Zeeman-effect back ground correction. A fast furnace program with no pyrolysis stage or chemical modifier was used, and the total duration of the time-temperature program of the graphite furnace was 45 s. The method detction limits calculated from blank samples were 9.5 mug 1~(-1), 0.18 mug l~(-1), 6.2 mug l~(-1) and 2.5 mug l~(-1) for As, Cd, Cr and Pb, respectively. Smple preparatin procedures are briefly described. The accuracy of the method was confirmed with a certified reference soil (recoveries 90-110%, within-batch RSD most often less than 5% with six replicates) and with 12 sediment samples from an international proficiency test. z-scores were calculated for the results of the seciment samples with 46 satisfactory and only 2 questionable results. Some analytical problems that were encountered during analysis are described. Fast furnace programs were found to be suitable for the simultaneous determination of the four elemens in aqua regia digests of soils and sediments.