Article ID Journal Published Year Pages File Type
1240555 Spectrochimica Acta Part B: Atomic Spectroscopy 2008 6 Pages PDF
Abstract

In this paper, two time-based flow injection (FI) separation pre-concentration systems coupled to graphite furnace atomic absorption spectrometry (GFAAS) for tellurium determination are studied and compared. The first alternative involves the pre-concentration of the analyte onto Dowex 1X8 employed as packaging material of a micro-column inserted in the flow system. The second set-up is based on the co-precipitation of tellurium with La(OH)3 followed by retention onto XAD resins. Both systems are compared in terms of limit of detection, linear range, RSD%, sample throughput, micro-columns lifetime and aptitude for fully automatic operation.The features of the Dowex system are: 37% efficiency of retention and an enhancement factor of 42 for a pre-concentration time of 180 seconds (sample flow rate = 3 ml min− 1) with acetic acid elution volumes of 80 μl. The detection limit (3 s) is 7 ng l− 1 and the relative standard deviation (n = 7200 ng l− 1) is 5.8%. The analytical performance of the XAD system is: 72% efficiency of retention and an enhancement factor of 25 for a pre-concentration time of 180 s (sample flow rate = 3 ml min− 1) with nitric acid elution volumes of 300 μl. The detection limit is 66 ng l− 1 and the relative standard deviation (n = 7200 ng l− 1) is 8.3%.Applications to the determination of tellurium in tap water and the validation of the analytical methodology employing SRM 1643e as certified reference material are shown.

Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
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