SORPTION AND PRECONCENTRATION OF COPPER AND CADMIUM ON SILICA-GEL MODIFIED WITH 3-AMINOPROPYLTRIETHOXYSILANE

3-Aminopropyltriethoxysilane, (C2H5O)3 Si(CH2)3NH2, loaded on silica gel was used as a pre-concentration sorbent for copper and cadmium prior to their determination by flame atomic absorption spectrometry (FAAS). Both batch and column methods were used for the separation of the above metals. The analytes are quantitatively retained on the proposed adsorbent at pH 6.5. The complexation capacity of the collector is 0.032 mmol Cu/g silica. In the batch method, the effects of shaking time and the ratio of metal/silica on the retention by the asorbent were investigated. Columns filled with the collector provided quantitative recovery of the above metals from standardized samples as well as from sodium chloride solutions.