Optimization of electromembrane extraction combined with differential pulse voltammetry using modified screen-printed electrode for the determination of sufentanil

In the present work, for the first time, electromembrane extraction (EME) combined with differential pulse voltammetry by multi-wall carbon nanotubes modified screen-printed carbon electrode has been reported for determining sufentanil. EME of sufentanil was carried out by applying a D.C. electrical potential through a thin supported liquid membrane (SLM). Charged drug molecules were extracted from an aqueous sample, through the SLM, into an acidic aqueous acceptor solution (20 μL) which is placed inside the lumen of a hollow fiber. Then, the acceptor solution was analyzed using differential pulse voltammetry (DPV). A Box–behnken design was used in order to optimize different variables affecting extraction efficiency using following DPV currents as signals. The main parameters which affect the extraction and determination of sufentanil were observed to be: accumulation time, 30 s; organic solvent, 2-nitrophenyl octyl ether; pH of the donor phase, 2.5; pH of the acceptor phase, 1.0; extraction time, 28 min; extraction output potential difference, 190 V and stirring rate, 1000 rpm. Under the optimal conditions, DPV currents were linear with the concentration of sufentanil within the range of 6.4 × 10−8–3.62 × 10−6 mol dm−3 with the detection limit (S/N = 3) of 2.0 × 10−8 mol dm−3. Finally, the proposed method has been successfully used for the determination of sufentanil in urine and plasma samples.

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► Combination of electromembrane extraction with electrochemical detection.
► Determination of sufentanil in human plasma and urine.
► The electrochemical determination performed on SPCE using 40 μL sample solution.
► The better responses obtained using MWCNT modified screen-printed carbon electrode.
► Response surface methodology was used for optimization of electromembrane extraction.