Salen impregnated silica gel as a new sorbent for on-line preconcentration of cadmium(Ⅱ)

摘要

A new sorbent - salen impregnated silica gel - was prepared and characterised for application as a minicolumn packing for flow-injection on-line preconcentration of cadmium(Ⅱ). The system was coupled with flame atomic absorption spectrometer (FI-FAAS). The optimal pH for Cd(Ⅱ) sorption was in the range of 7.4-8.8 and nitric acid (1%, v/v) was efficient as eluent. Sorption was most effective within the sample flow rate up to 7mLmin-1. Sorption capacity of the sorbent found in a batch procedure was 26.3μmolg-1 (2.95mgg-1). Enrichment factor (EF) and limit of detection (LOD) obtained for 120-second loading time were 113 and 0.26 ngL-1 respectively. The sorbent stability in the working conditions was proved for at least 100 preconcentration cycles. The evaluated method was applied to Cd(Ⅱ) determination in various water samples.