Preconcentration of volatile elements on quartz surface prior to determination by atomic spectrometry

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2004
Korkmaz, Deniz
Hydride generation technique is frequently used for the detection of elements as As, Se, Sb, Sn, Bi, Ge, Te and Pb that form volatile hydrides in solution using a reductant. In this study, a novel quartz trap for on-line preconcentration of volatile analyte species was designed. Pb, Sb and Cd were selected as analyte elements and chemical vapour generation technique was employed for generation of their volatile species in flow systems. The trapping medium was formed by external heating of either the inlet arm of the quartz tube atomizer or a separate cylindirical quartz tube. Generated analyte species were trapped on quartz surface heated to the collection temperature and the collected species were revolatilized when the trap was heated further to releasing temperature and hydrogen gas was introduced in the trapping medium. The conventional quartz T-tube and multiple microflame quartz tube were employed as atomizers. The influence of relevant experimental parameters on the generation, collection and revolatilization efficiencies was investigated. Optimum conditions, performance characteristics of the trap and analytical figures of merit are presented. Experimental design was used for optimizations in some cases. Standard reference materials were analyzed to assess the accuracy of the proposed method. For a collection period of 1.0 minute for Pb, 2.0 minutes for Sb and 3.0 minutes for Cd, 3s limit of detections, in pg ml-1, were 19, 3.9 and 1.8, respectively. In cases of Sb and Cd, the limits of detections obtained are the same as the best attained with in-situ trapping in graphite furnaces.

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Citation Formats
D. Korkmaz, “Preconcentration of volatile elements on quartz surface prior to determination by atomic spectrometry,” Ph.D. - Doctoral Program, Middle East Technical University, 2004.