Synthesis and application of chloromethylated polystyrene modified with 1-phenyl-1,2-propanedione-2-oxime thiosemicarbazone (PPDOT) as a new sorbent for the on-line preconcentration and determination of copper in water, soil, and food samples by FAAS

Abstract

In this paper, we report a simple and sensitive on-line solid phase extraction system for the preconcentration and determination of Cu(II) by flame atomic absorption spectrometry (FAAS). This method is based upon the on-line retention of copper at pH 5.0 on a minicolumn packed with chloromethylated polystyrene modified by 1-phenyl-1,2-propanedione-2-oxime thiosemicarbazone (PPDOT) as a new solid-phase extraction (SPE) sorbent. The retained Cu(II) ions were eluted with 1.0 M HNO 3, and transported directly to FAAS for determination. Several chemical and flow variables were studied and optimized for a quantitative preconcentration and determination of copper(II). At the optimized conditions, for preconcentration of 10.0 mL of a sample solution, a linear calibration graph was obtained over the concentration range of 3.00–120.0 μg L −1 for Cu(II). The limit of detection (3 σ), limit of quantification (10 σ), and enrichment factor are 0.56 μg L −1, 2.0 μg L −1 and 41, respectively. The relative standard deviation ( n = 6) at 20 μg L −1 of Cu(II) is 2.0%. This method could be applied for determination of trace amounts of Cu(II) in water, soil, and food samples with satisfactory results.