Supported liquid membranes for the determination of vanillin in food samples with amperometric detection

Abstract

A supported liquid membrane system has been developed for the extraction of vanillin from food samples. A porous PTFE membrane is impregnated with an organic solvent, which forms a barrier between two aqueous phases. The analyte is extracted from a donor phase into the hydrophobic membrane and then back extracted into a second aqueous solution, the acceptor. The determination (100–1400μgml−1 vanillin) was performed using a PVC-graphite composite electrode versus Ag/AgCl/3MKCl at +0.850V placed in a wall-jet flow cell as amperometric detector. The solid sample is directly placed in the membrane unit without any treatment, and the analyte was extracted from the sample, passes through the membrane and conduced to the flow cell by the acceptor stream. The limit of detection (3σ) was 44μgml−1. The method was applied to the determination of vanillin (9–606μgg−1) in food samples.