Electrochemically controlled fiber-in-tube solid-phase microextraction method for the determination of trace amounts of antipsychotic drugs in biological samples.

In this study, a novel 'fiber-in-tube' configuration was applied to electrochemically controlled fiber-in-tube solid-phase microextraction of antipsychotic drugs (perphenazine and chlorpromazine) from biological samples. To prepare an electrochemically controlled fiber-in-tube solid-phase microextraction column, first eight stainless-steel wires were placed into the stainless-steel column. Then, a nanostructured Cu-Cr-Al ternary layered double hydroxide/polythiophene coating was prepared on the inner surface of the stainless-steel tube and on the surfaces of the stainless-steel wires by a facile in situ electrodeposition method. The nanostructured coating exhibited enhanced long lifetime, good mechanical stability, high porosity, and large specific surface area compared with polythiophene and Cu-Cr-Al layered double hydroxide coatings. Under the optimal conditions, the limits of detection were in the range of 0.07-0.8 μg/L. This method showed good linearity for perphenazine and chlorpromazine in the ranges of 0.3-300 and 0.2-300 μg/L, respectively, with coefficients of determination more than 0.9982. The inter- and intra-assay precisions (RSD%, n = 3) were in the ranges of 3.0-5.1 and 2.5-4.5% at three concentration levels of 5, 25 and 50 μg/L, respectively. Finally, the method was applied for the analysis of the drugs in human urine and plasma samples.