On-line solid phase extraction method based on flow injection-FAAS using 1,10-phenanthroline modified chelating resin for chromium speciation in industrial water samples

Abstract

A solid phase extraction method for the speciation of chromium in industrial water samples using flow injection-FAAS has been described. 1,10-Phenanthroline immobilized Amberlite XAD-16 chelating resin was synthesized and used as the solid phase extractant. For enhancing Cr(III) preconcentration using the solid phase extractant, all chemical and flow variables were optimized. Total chromium was determined by reducing Cr(VI) to Cr(III) using hydroxylamine hydrochloride. The chelating resin was found to tolerate high amounts of commonly present matrix ions in water samples. The preconcentration factor and detection limit for 120 s preconcentration time were found to be 84 and 0.09 ng mL⁻¹. The precision (% RSD) at the 100 μg L⁻¹ level was 1.0%. The linearity for Cr(III) measurements was up to 580 μg L⁻¹. Standard Cr(III) and Cr(VI) solutions traceable to NIST were used for spike recovery studies in industrial water samples. The validation of this method was carried out using SRM 1643e (Trace Elements in Water) supplied by NIST, USA.