On-line solid phase extraction system for chromium determination in water samples by flow injection-flame atomic absorption spectrometry

An on-line solid phase extraction system has been established for flow injection flame atomic absorption spectrometric determination of chromium on Chromotrope 2R coated Amberlite XAD-1180 (2R-1180) resin. Some parameters such as pH, flow rates of sample and elution solution, matrix effects on the quantitative recoveries of chromium from the resin were examined. The detection limit (3sigma) was 2.59 mug/L for preconcentration at 6.5 mL/min. The method was applied for the determination of traces chromium in natural water samples with satisfactory results (relative standard deviations below 5%, recoveries >95%).