Use of supported liquid membranes incorporated in a flow system for the direct determination of eugenol in spice samples

Abstract

A method for the determination of eugenol in spice samples based on the use of supported liquid membranes coupled to a flow system was developed. The solid sample is placed directly in the membrane unit without any treatment and the analyte is extracted from the sample, passes through the membrane and is conducted to the flow cell by the acceptor stream. This stream flows through the detector, allowing the measurement of the analyte by using a PVC–graphite composite electrode, versus Ag/AgCl/3 M KCl at +0.3 V, placed in a wall-jet flow cell as amperometric detector. The method allowed the determination of eugenol in the range 0.5–30 μg ml⁻¹ with a relative standard deviation of 5%. Results provided by the proposed procedure when applied to clove and seasoning samples agreed well with those obtained by a reference method.