Electromembrane extraction of opioids from biological samples before analysis with chromatographic methods

Abstract

Introduction: Electromembrane extraction (EME) is an extraction method in micro-scale in which charged compounds are extracted from the donor phase (sample solution) via a supported liquid membrane (SLM) containing a water-immiscible organic solvent into an acceptor phase. Aim of this study: In this study, EME coupled with chromatographic methods was developed for the extraction and measuring of tramadol and methadone from biological samples. Method: Tramadol has extracted from the exhaled breath condensate (EBC) samples through the EME method, and determined with the HPLC-UV method. In the following, to enhance the efficiency and selectivity of extraction in the EME method, gold nanoparticles modified with β-cyclodextrin (β-CDs modified AuNPs) were used in the SLM structure for the extraction of methadone and determined with the HPLC-UV method. Results: Under the optimum conditions of the EME for extraction of tramadol, a pre-concentration factor of 128-fold corresponds to an extraction recovery of 64.1% was achieved. Acceptable linearity was calculated in the concentration range of 5.0–1000 ng mL-1 (R2 = 0.9999). The proposed method indicated a good limit of detection (1.5 ng mL-1) and a limit of quantitation (5.0 ng mL-1). In the methadone extraction for obtaining the effect of the presence of β-CDs modified AuNPs, the extraction efficiency of EME and β-CDs modified AuNPs/EME techniques were compared. In optimal conditions, compared with the EME, the β-CDs modified AuNPs/EME method indicated better extraction efficacy in a short time. In addition, the β-CDs modified AuNPs/EME technique demonstrated a lower limit of detection (5.0 ng mL-1), better extraction recovery (68%), and a better pre-concentration factor (135). Conclusion: The validated techniques were successfully used for the determination of tramadol and methadone in real samples.