Ali Mohebi
1 
, Mir Ali Farajzadeh
1,2 , Abolghasem Jouyban
3 , Mahboob Nemati
4,5 , Mohammad Reza Afshar Mogaddam
4,6* 1 Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
2 Engineering Faculty, Near East University, 99138, Nicosia, North Cyprus, Mersin 10, Turkey.
3 Pharmaceutical Analysis Research Center and Pharmacy Faculty, Tabriz University of Medical Sciences, Tabriz, Iran.
4 Food and Drug Safety Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
5 Halal Research Center, Ministry of Health and Medical Education, Tehran, Iran.
6 Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
Abstract
Background: Because of the narrow therapeutic range of tricyclic antidepressant drugs, their determination in biological samples is of great importance. In this work, a fast and environment friendly sample pretreatment method based on a dispersive liquid–liquid microextraction was developed for the extraction and preconcentration of four tricyclic antidepressants including nortriptyline, amitriptyline, desipramine, and clomipramine in urine prior to their determinations by gas chromatography–mass spectrometry.
Methods: In the suggested method, an appropriate mixture of Na2SO4 solution (as phase separation agent and disperser) containing isopropanol (extraction solvent) is rapidly injected into an alkaline aqueous sample solution containing Na2SO4 and the analytes. As a result, a cloudy mixture is formed and the tiny droplets of the extractant containing the extracted analytes are collected on the surface of the aqueous phase after centrifuging. Finally, an aliquot of the collected organic phase is removed and injected into the separation system for the quantitative analysis.
Results: Under the optimum conditions, the enrichment factors and extraction recoveries were in the ranges of 380–440 and 76–88%, respectively. The limits of detection and quantification were obtained in the ranges of 11–24, and 41–75 ng/L, respectively. The relative standard deviations of the proposed method were ≤ 6.1% for intra– (n=6) and inter–day (n=4) precisions at a concentration of 100 ng/L of each analyte.
Conclusion: The introduced method was satisfactorily utilized for the simultaneous determination of the selected tricyclic antidepressant drugs in the patient’s urine samples.