Cloud point preconcentration of germanium and determination by hydride generation atomic absorption spectrometry

Cloud point methodology has been successfully employed for the preconcentra tion of germanium at trace levels from aqueous samples prior to hydride gen eration flame atomic absorption spectrometry (HGAAS). Germanium was taken i nto complex with quercetin in aqueous non-ionic surfactant (Triton X-114) m edium and concentrated in the surfactant rich phase by bringing the solutio n to the cloud point temperature (19 degrees C). The preconcentration of on ly 50 mi of solution with 0.1% Triton X-114 and 2 x 10(-5) M quercetin at p H 6.4 gives a preconcentration factor of 200. Under these conditions, the d etection limit (3s) and the sensitivity of the cloud-point extraction-HGAAS system were 0.59 and 0.0620 mu g 1(-1), respectively. The extraction effic iency was investigated at low germanium concentrations (10-30 mu g 1(-1)) a nd satisfactory recoveries (93-105%) were obtained. (C) 2000 Elsevier Scien ce B.V. All rights reserved.