Methadone (MET) metabolism has been largely demonstrated with a high inter-individual variability and, therefore, quantification of MET is very important for therapeutic drug monitoring. A cation-selective exhaustive injection and sweeping MEKC (CSEI-Sweeping) was first developed to analyze MET and its two metabolites, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and 2-ethyl-5-methyl-3,3-diphenyl-1-pyrroline (EMDP), in human serum. After pretreatment, the samples were electrokinetically injected into capillary (10 kV, 500s) and swept by the separation phosphate buffer (100 mM, pH 4.0) containing 20% tetrahydrofuran and 100 mM SDS at -15 kV. The LODs were 200 pg/mL for MET and EMDP, and 400 pg/mL for EDDP. Ten volunteers were administered MET (5.0-120.0 mg/day) orally for 84 days and serum samples were taken after the daily dose of MET (days 1, 2, 7, 14, 28, 56 and 84) individually. This method was used for monitoring MET and its metabolites in heroin addicts and for pharmacokinetic investigations.
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http://dx.doi.org/10.1016/j.chroma.2011.07.086 | DOI Listing |
J Chromatogr A
April 2022
State Key Laboratory of Component-Based Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China; Tianjin Key Laboratory of Phytochemistry and Pharmaceutical Analysis, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China. Electronic address:
An highly sensitive, rapid and enantioselective method was developed for the enantioseparation and determination of citalopram enantiomers by cation selective exhaustive injection-sweeping-cyclodextrin modified electrokinetic chromatography (CSEI-sweeping-CDEKC). The optimized conditions were: 50 mM pH 3.0 phosphate solution with 25 mg·mL S-β-CD used as background buffer, 50 mbar 300 s hydrodynamical injection of 150 mM pH 3.
View Article and Find Full Text PDFACS Sens
November 2020
Chemistry Institute, Saint Petersburg State University, 26 Universitetskiy prospect, 198504 Saint Petersburg, Russia.
Here, we report on systematic investigation of the impact of coextraction of the aqueous electrolyte and anion interference on the response of cation-selective bulk optodes. It is evident that to deliberately manage the properties of chemical sensors and to apply them in routine analysis, one should have exhaustive insight into their operation mechanism. Despite the extensive research in the field of ionophore-based optodes and numerous attempts for their practical application, the understanding of how coextraction of an aqueous electrolyte influences its response characteristics has not been developed thus far.
View Article and Find Full Text PDFJ Pharm Biomed Anal
May 2019
Ministry of Education Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China. Electronic address:
Detection of amino acids (AAs) in blood is helpful to diagnose some diseases. In this work, a method is developed for determination of trace amounts of AAs in bovine blood by combining solid phase extraction (SPE) and capillary electrophoresis (CE). Zeolitic imidazolate framework-8 (ZIF-8) nanoparticles are prepared and used as adsorbents to simultaneously extract three AAs (tryptophan, tyrosine, phenylalanine).
View Article and Find Full Text PDFTalanta
January 2019
School of Pharmacy, Shenyang Pharmaceutical University, Wenhua Road 103, Shenyang, Liaoning Province, PR China. Electronic address:
For the aim of simultaneously performing the enantioseparation and determination of the trace enantiomers in plasma samples, enantioseparation by HPLC using five kinds of chiral stationary phases were initially investigated. But unfortunately, enantioseparation could not be detected in reversed mobile phase mode with all the five columns. For this reason, two simple, economical and highly efficient online preconcentration methods, large volume sample stacking and sweeping (LVSS-sweeping) and cation-selective exhaustive injection and sweeping (CSEI-sweeping) both followed by the cyclodextrin modified electrokinetic chromatography (CDEKC) were examined in the present work.
View Article and Find Full Text PDFElectrophoresis
August 2018
School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, P. R. China.
A method consisting of cation-selective exhaustive injection and sweeping (CSEI-sweeping) as online preconcentration followed by a cyclodextrin modified electrokinetic chromatography (CDEKC) enantioseparation has been developed for the simultaneous determination of two brompheniramine enantiomers in rat plasma. In this method, analytes were electrokinetically injected at a voltage of 8 kV for 80 s in a fused-silica capillary. Prior to the injection, the capillary was rinsed with 50 mM phosphate buffer of pH 3.
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