Simultaneous determination of methylephedrine and pseudoephedrine in human urine by CE with electrochemiluminescence detection and its application to pharmacokeinetics
ABSTRACT A novel method for the determination of ephedra alkaloids (methylephedrine and pseudoephedrine) was developed by electrophoresis capillary (CE) separation and electrochemiluminesence detection (ECL). The use of ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate, BMIMBF(4)) improved the detection sensitivity markedly. The conditions for CE separation, ECL detection and effect of ionic liquid were investigated in detail. The two ephedra alkaloids with very similar structures were well separated and detected under the optimum conditions. The limits of detection (signal-to-noise ratio = 3) in standard solution were 1.8 x 10(-8) mol/L for methylephedrine (ME) and 9.2 x 10(-9) mol/L for pseudoephedrine (PSE). The limits of quantitation (signal-to-noise ratio = 10) in human urine samples were 2.6 x 10(-7) mol/L for ME and 3.6 x 10(-7 )mol/L for PSE. The recoveries of two alkaloids at three different concentration levels in human urine samples were between 81.7 and 105.0%. The proposed method was successfully applied to the determination of ME and PSE in human urine and the monitoring of pharmacokinetics for PSE. The proposed method has potential in therapeutic drug monitoring and clinical analysis.
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ABSTRACT: An investigation was carried out to determine the relationship between cells biomass, chlorophyll content and production two major alkaloids of Ephedra procera - ephedrine and pseudoephedrine, in callus culture under different ranges of plant growth promote regulators. We find out that kin as a cytokinin is more suitable than BAP for callus and ephedrine and pseudoephedrine productions, subsequently the treatments containing 2 mg l-1 NAA with 1 mg l-1 kin can produce the highest cells biomass with production of 108.1 ± 0.6 μg g-1 dry weight for ephedrine and 730.3 ± 1 μg g-1 dry weight for pseudoephedrine, total chlorophyll content was recorded as 118.4 ± 7.6 μg mg-1 dry weight in this treatment. Considerably in 5th subculture, rhizogenesis occurred in 18% of NAA: 2; kin: 1 treatment and we found out the ephedrine and pseudoephedrine content increased significantly compared with undifferentiated cells in the same hormonal range. This increasing also involved total chlorophyll and chlorophyll b accumulation.
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ABSTRACT: A novel and sensitive method for the simultaneous determination of enoxacin and ofloxacin has been established using capillary electrophoresis (CE) coupled with electrochemiluminescence (ECL) detection based on the ECL enhancement of tri(2,2-bipyridyl)ruthenium(II). The conditions for sample solvent type, CE separation and ECL detection were investigated systematically. The analytes were well separated and detected within 7 min. The limits of detection (S/N = 3) of enoxacin and ofloxacin are 9.0 x 10(-9) and 1.6 x 10(-8) mol/L, respectively. The precisions (RSD%) of intraday and interday are less than 2.1 and 4.0%, respectively. The limits of quantitation (S/N = 10) of enoxacin and ofloxacin are 3.2 x 10(-7) and 5.4 x 10(-7) mol/L in human urine samples and 4.1 x 10(-7) and 6.9 x 10(-7) mol/L in human serum samples, respectively. The recoveries of enoxacin and ofloxacin at different concentration levels in human urine, serum and eye drop samples are between 94.0 and 106.7%. The proposed method was successfully applied to the determination of the enoxacin and ofloxacin in human urine, serum and eye drop samples and the monitoring of pharmacokinetics of ofloxacin in human body.Biomedical Chromatography 01/2009; 24(9):941-7. DOI:10.1002/bmc.1389 · 1.66 Impact Factor
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ABSTRACT: This review presents a comprehensive survey of recent progress on electrochemiluminescence (ECL) detection coupled with capillary electrophoresis (CE). The fundamental theories involved in CE-ECL, e.g., the mechanism involving both coreactant-based and inhibitor-based ECL, as well as the possible analytes to be detected by CE-ECL are summarized. Different schemes for the construction of CE-ECL apparatus, including methods for preparing the working electrode, approaches for addition of ECL reagents, ways to fabricate electrical decouplers, and factors affecting ECL efficiency are reviewed. Discussion of the literature related to the application of CE-ECL from January 2005 to September 2010 is sorted by the corresponding analyte matrixes, namely, the standard solution, urine, serum and plasma, and other matrixes. Finally, possible trends for CE-ECL in the near future are discussed.Analytical and Bioanalytical Chemistry 12/2010; 399(10):3323-43. DOI:10.1007/s00216-010-4445-6 · 3.58 Impact Factor