A novel platform sensing based on combination of electromembrane-assisted solid phase microextraction with linear sweep voltammetry for the determination of tramadol

This paper aims to introduce a new analytical strategy based on electromembrane-assisted solid phase microextraction (EM-SPME) coupled with electrochemical detection for the electroanalysis of tramadol as a model analyte from urine samples. For this purpose, reduced graphene oxide (r-GO) spin-coated pencil lead was used not only as a solid sorbent for SPME and reinforced cathode of electromembrane extraction (EME) but also, as the working electrode (pencil modified electrode) in electrochemical analysis. A Box-Behnken design and the response surface methodology were used for the optimization of different variables affecting the extraction efficiency. In optimized condition, the detection limit of tramadol was obtained to be 0.0030 μg mL−1. Dynamic ranges of the method were obtained within the range of 0.010-0.50 and 0.50-50 μg mL−1. The process of coupling SPME with EME decreases the detection limit of the method in urine samples. In addition, EM-SPME can remove the interfering effect of acids, carbohydrates, anions and also other polar compounds that suppress low log P during the measurement.