Simultaneous determination of traces of iron, cobalt, nickel, copper, mercury and lead in water by energy-dispersive x-ray fluorescence spectrometry after preconcentration as their piperazino-1,4-bis(dithiocarbamate) complexes
✍ Scribed by Oi-Wah Lau; Sing-Yiu Ho
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 715 KB
- Volume
- 280
- Category
- Article
- ISSN
- 0003-2670
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✦ Synopsis
A bidentate chelating agent has been proposed to preconcentrate seven metal ions dissolved in an aqueous sample for their simultaneous determination usiug energy-dispersive x-ray fluorescence spectrometty. The metal ions are precipitated as their polymeric piperaxino-1,4-bis(dithiocarbamate) chelates, which are then collected by vacuum filtration on a Millipore membrane filter for direct examination by x-ray fluorescence analysis. Iron, cobalt, nickel, copper and xinc are determined by means of their K, x-rays and mercury and lead by means of their L, x-rays. A detection limit in the pg 1-l range can be achieved for all metals tested in 250~ml water samples with a counting time of 600 s. Effective precipitation of all metals occurs at pH 6-7. The recoveries of eight analyses of the metals in a multielement standard using the proposed method ranged from 97 to 105% and the precision ranged from 2.3 to 3.1%. High concentrations of calcium and magnesium do not interfere with the method. The method is simple, sensitive and accurate, and has been used for the simultaneous determination of the seven metals under study in environmental samples and synthetic mixtures.