Preconcentration of germanium on mercapto-modified silica gel

A simple method for the determination of ultra-trace amounts of germanium i n natural waters has been developed. Germanium was preconcentrated using si lica having mercapto functional groups, namely mercapto silica and determin ed by hydride generation flame atomic absorption spectrometry (HGAAS). Util ising mercapto silica, satisfactory recovery values (> 95%) were obtained a t natural pH, for germanate concentrations as low as 50 ng 1(-1) Considerin g the highest preconcentration factor (400-fold) obtained, the sensitivity and 3s-detection limit of mercapto silica-HGAAS system can be expressed as 3.65 ng 1(-1)/0.0044 AU and 0.813 ng 1(-1), respectively. Interference effe cts of diverse ions were investigated for HGAAS and mercapto silica-HGAAS s ystems. (C) 2000 Elsevier Science B.V. All rights reserved.