Automatic on line preconcentration and determination of lead in water by ICP-AES using a TS-microcolumn

• Published in: Talanta (Oxford) Vol. 62; no. 3; pp. 503 - 510
• Main Authors: Zougagh, M., Garcı́a de Torres, A., Vereda Alonso, E., Cano Pavón, J.M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 27.02.2004; Oxford Elsevier
• Subjects: Analysis methods; Analytical chemistry; Applied sciences; Chemistry; Exact sciences and technology; Flow-injection on-line preconcentration; ICP-AES; Lead; Natural water pollution; Pollution; Spectrometric and optical methods; TS-gel; Water; Water treatment and pollution; ICP-AES; Water; Lead; TS-gel; Flow-injection on-line preconcentration; Atomic emission spectrometry; Calibration; EDTA; Inductive coupling plasma spectrometry; Optimization; Chemical enrichment; Microbore column; Sorption; Detection limit; Thermoelectric atomization; Standard deviation; Silica gel; Water pollution; Flow injection; Atomic absorption spectrometry
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2003.08.033

A simple, sensitive, low-cost and rapid, flow injection system for the on-line preconcentration of lead by sorption on a microcolumn packed with silica gel funtionalized with methylthiosalicylate (TS-gel) was developped. The metal is directly retained on the sorbent column and subsequently then eluted from it by EDTA. Five variables (sample flow rate, eluent flow rate, eluent concentration, pH and buffer concentration) were considered as factors in the optimization process. Interactions between analytical factors and their optimal levels were investigated using two level factorial and Box–Behnken designs. The optimum conditions established were applied to the determination of lead by flow injection inductively coupled plasma atomic emission spectrometry (FI-ICP-AES). The proposed method has a linear calibration range from 10 to at least 500 ng ml −1 of lead. At a sample frequency of 24 h −1 and a 120 s preconcentration time, the enrichment factor was 41, the detection limit was 15.3 ng ml −1 ( S/ N=3) and the precision, expressed as relative standard deviation, was 0.9% (at 100 ng ml −1). Validation of the developed method was carried out against electrothermal atomic absorption spectrometry analysis without statistically significant differences between the proposed method and the atomic absorption method.