THERMAL LENS SPECTROMETRIC DETERMINATION OF HEXAVALENT CHROMIUM

The applicability of thermal lens spectrometry (TLS) for quantificatio n and routine determination of hexavalent chromium was investigated by using a collinear dual beam thermal lens spectrometer. In aqueous sol utions the LOD of 0.1 mu gl(-1) was obtained for Cr(VI) by using 160 m W laser power. The performance of the technique was verified by the de termination of hexavalent chromium in standard reference water samples (NIST SRM 1643a and NIST SRM 1643c) and comparing the results for Cr( VI) in CCA (Cr, Cu, As)-treated timber extracts to concentrations obta ined by atomic absorption spectrometry (AAS), Good agreement between t he TLS results and reported values for Cr(VI) in SRMs as well as AAS r esults for Cr(VI) in CCA-treated timbers confirmed that TLS is a relia ble and accurate analytical technique applicable for the determination of Cr(VI) in aqueous solutions at concentration levels 0.5-100 mu gl( -1).