DIRECT DETERMINATION OF TRACES OF Ag, Cd, Pb, Bi, Cr, Mn, Co, Ni, Li, Be, Cu AND Sb IN ENVIRONMENTAL WATERS AND GEOLOGICAL MATERIALS BY SIMULTANEOUS MULTI-ELEMENT GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROMETRY WITH ZEEMAN-EFFECT BACKGROUND CORRECTIO

摘要

A method was developed for direct determination of minor and trace amounts of Cr. Mn, Cu. Ni, Co, Li, Pb, Cd, Bi. Sb, Be and Ag in silicate rock, lake and stream sediments using a microwave oven dissolution method and a multi-element graphite furnaceatomic absorption spectrometer equipped with a Zeeman-effecl background correction device. The measurement technique was also suitable for direct determination of trace and ultra-trace amounts of these elements in drinking and scawatcr samples. A rock orsediment sample was brought into solution in a Teflon vessel by heating in a microwave oven with a mixture of hydrofluoric acid and aqua regia, followed by a further heating with a mixture of boric acid and ethylenediamineletraacetic acid. The specifiedelements were directly determined in a group of four elements in one firing and eight elements in two firings from this solution or from a diluted solution using the optimum operating parameters developed in this work. The method, tested with 23 international reference rocks and sediments and seven international quality control and reference water samples, showed good to excellent agreement with the recommended values.