Combination of gel-electromembrane extraction with switchable hydrophilicity solvent-based homogeneous liquid-liquid microextraction followed by gas chromatography for the extraction and determination of antidepressants in human serum, breast milk and wastewater

The current study presents for the first time a combination of the gel electromembrane extraction (GEL-EME) and switchable hydrophilicity solvent-based homogeneous liquid-liquid microextraction (SHS-HLLME) methods which can be used as an efficient hyphenated extraction procedure. This coupled method, which was followed by GC-FID, was applied for quantification of antidepressants (desipramine, clozapine, and citalopram) in biological and wastewater samples. The effective parameters of both GEL-EME and SHS-HLLME procedures were optimized. Using an agarose gel membrane, analytes were extracted from 7.0 mL of the sample solution to 500 mu L of the aqueous acceptor solution. The maximum extraction of analytes of interest was obtained under the optimized conditions (pH of acceptor solution, 5.0; pH of gel membrane, 5.0; pH of sample solution, 7.0, voltage value, 30 V; and extraction time, 30 min). Then, the acceptor solution was transferred to the extraction cell and the SHS-HLLME procedure was conducted again under the optimized conditions. Dipropylamine (50 mu L) was selected as an extraction solvent. The introduced technique exhibited good linearities with coefficients of determinatin (R-2) higher than 0.983 and an acceptable linear range of 5.0-1000 ng/mL. Accordingly, the limit of detection was <= 1.0 ng/mL (S/N = 3) for all analytes, and the high enrichment factors were obtained in the range of 178.7-194.8. Moreover, the corresponding repeatability was from 4.0 to 8.7% (n = 3). The proposed method was successfully utilized to determine trace levels of the drugs in human serum, wastewater, and breast milk samples. (C) 2020 Elsevier B.V. All rights reserved.