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

Cloud point methodology has been successfully employed for the preconcentration of germanium at trace levels from aqueous samples prior to hydride generation flame atomic absorption spectrometry (HGAAS). Germanium was taken into complex with quercetin in aqueous non-ionic surfactant (Triton X-114) medium and concentrated in the surfactant rich phase by bringing the solution to the cloud point temperature (19°C). The preconcentration of only 50 ml of solution with 0.1% Triton X-114 and 2×10−5 M quercetin at pH 6.4 gives a preconcentration factor of 200. Under these conditions, the detection limit (3s) and the sensitivity of the cloud-point extraction-HGAAS system were 0.59 and 0.0620 μg l−1, respectively. The extraction efficiency was investigated at low germanium concentrations (10–30 μg l−1) and satisfactory recoveries (93–105%) were obtained.