title: Dispersive liquid-liquid microextraction combined with high-performance liquid chromatography for the determination of clozapine and chlorpromazine in urine.
abstract: A simple method has been proposed for the determination of clozapine (CLZ) and chlorpromazine (CPZ) in human urine by dispersive liquid-liquid microextraction (DLLME) in combination with high-performance liquid chromatography-ultraviolet detector (HPLC-UV). All important variables influencing the extraction efficiency, such as pH, types of the extraction solvent and the disperser solvent and their volume, ionic strength and centrifugation time were investigated and optimized. Under the optimal conditions, the limit of detection (LODs) and quantification (LOQs) of the method were 13 and 39 ng/mL for CLZ, and 2 and 6 ng/mL for CPZ, respectively. The relative standard deviations (RSDs) of the targets were less than 5.1% (C=0.100 μg/mL, n=9). Good linear behaviors over the tested concentration ranges were obtained with the values of R (2)>0.999 for the targets. The absolute extraction efficiencies of CLZ and CPZ from the spiked blank urine samples were 98.3% and 97.8%, respectively. The applicability of the technique was validated by analyzing urine samples and the mean recoveries for spiked urine samples ranged from 93.3% to 105.0%. The method was successfully applied for the determination of CLZ and CPZ in real human urine.
authors.affiliation: Key Laboratory of Natural Medicinal Chemistry and Resources Evaluation of Hubei Province, College of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.affiliation: Key Laboratory of Natural Medicinal Chemistry and Resources Evaluation of Hubei Province, College of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China. cmxiong2002@yahoo.com.cn.
authors.forename: Chaomei
authors.initials: C
authors.lastname: Xiong
authors.affiliation: Key Laboratory of Natural Medicinal Chemistry and Resources Evaluation of Hubei Province, College of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
authors.forename: Jinlan
authors.initials: J
authors.lastname: Ruan
authors.affiliation: The Second Psychiatric Hospital, Wuhan, 430084, China.
authors.forename: Zou
authors.initials: Z
authors.lastname: Su
mesh_terms: D014150:Antipsychotic Agents / Q000652:urine; D002746:Chlorpromazine / Q000652:urine*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003024:Clozapine / Q000652:urine*; D006801:Humans; D059627:Liquid Phase Microextraction / Q000379:methods*; D012680:Sensitivity and Specificity; D014466:Ultraviolet Rays
chemical_list: D014150:Antipsychotic Agents; D003024:Clozapine; D002746:Chlorpromazine