Preconcentration, determination and speciation of chromium(III) using solid phase extraction and flame atomic absorption spectrometry

A facile, reliable and reproducible method for speciation and determination of the traces amounts of chromium(Ill) in waste water has been developed. The method was based on complex formation on the surface of the ENVI-18 DSK (TM) disks followed by stripping of the retained species by minimum amounts of appropriate organic solvents. The elution was efficient and quantitative. The effects of potential interfering ions, pH, ligand amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break-through volume was found to be about 1500 mL providing a preconcentration factor of 300. The maximum capacity of the disks was found to be 225 +/- 3.9 mu g for Cr3+ A limit of detection of 0.02 ng.mL(-1) was obtained, and the method was applied for determination of chromium in electroplating industries waste water located in the eastern regions of Tehran.