Chromium Speciation in Contaminated Water Samples Using PTFE Beads Packed Minicolumn and FI-FAAS Determination

A spectroanalytical method for remediation of chromium species from contaminated water samples based on flow injection hyphenated to a flame atomic absorption spectrometer is proposed. lminodiacetic acid (IDA) was used as the chelating agent, and the chromium-IDA complex was preconcentrated on the minicolumn filled with polytetra-fluoroethylene (PTFE) beads. The chemical and flow variables were optimized. The effect of commonly occurring matrix ions on the recovery of the chromium species was also studied. For a preconcentration time of 120 s, preconcentration factors and detection limits achieved for Cr(III)/Cr(VI) were 68/59, 0.11/0.13 mu g L-1, respectively. The relative standard deviation for 5 replicates of measurements for 100 mu g L-1 level was 1.2/1.4% for Cr(III)/Cr(VI), respectively. Real water samples collected from industrial sites and the Yamuna river were analyzed and spike recovery tests were performed. The method validation was done by analyzing the chromium concentration in NIST SRM 1640a Trace Elements in Natural Water.