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Vijaya Bhaskar Reddy Ambavaram Venugopal Nandigam Madhavi Vemula Gangadhara Reddy Kalluru Madhavi Gajulapalle 《Biomedical chromatography : BMC》2013,27(7):916-923
A sensitive and selective liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed and validated for simultaneous determination of urapidil and aripiprazole in human plasma. A simple liquid–liquid extraction with ethyl acetate was used for the sample preparation. Chromatographic separation was achieved on a Phenomenex C18 (4.6 × 50 mm, 5 µm) column with 0.1% formic acid–acetonitrile (10:90, v/v) as the mobile phase with flow rate of 0.6 mL/min. The quantitation of the target compounds was determined in a positive ion multiple reaction monitoring mode. Calibration plots were linear over the range of 2.0–2503.95 ng/mL for urapidil and 1.0–500.19 ng/mL for aripiprazole. The lower limit of quantitation for urapidil and aripiprazole was 2.0 and 1.0 ng/mL, respectively. Mean recovery was in the range of 69.94–75.62% for both analytes and internal standards. Intra‐day and inter‐day precisions of the assay at three concentrations were 2.56–5.89% with accuracy of 92.31–97.83% for urapidil, and 3.14–6.84% with accuracy of 91.38–94.42% for aripiprazole. The method was successfully applied to human pharmacokinetic study of urapidil and aripiprazole in healthy human male volunteers. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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V. Padmavathi T. V. Ramana Reddy A. Balaiah K. Audisesha Reddy D. Bhaskar Reddy 《Phosphorus, sulfur, and silicon and the related elements》2013,188(5):1223-1235
Some new heterocyclic compounds containing selenadiazole, thiadiazole and diazaphosphole fused to cyclohexanones have been prepared and characterized by spectral data. 相似文献
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Bhaskar Garg Shiou-Ling Lei Shou-Ching Liu Tanuja Bisht Jen-Yu Liu Yong-Chien Ling 《Analytica chimica acta》2012
The time-of-flight secondary ion mass spectrometry (TOF-SIMS) has emerged as a powerful tool for the unswerving detection of biomolecules, in particular, proteins and peptides. To date, there is very little information available on the direct determination of trimethyl/triethyl amines using TOF-SIMS. One major hurdle in this regard is an ultrahigh vacuum system, usually needed in TOF-SIMS, which hampers its usability to trimethyl/triethyl amines owing to their high evaporation rate. We designed an efficient and sensitive protocol for rapid identification and sensitive determination of tertiaryalkyl amines using TOF-SIMS. The amines were derivatized by reaction with 1,4-butane sultone and sulphuric acid sequentially to afford the corresponding sulphonic acidic ionic liquids (ILs). The TOF-SIMS analysis of these task-specific ILs (TSILs) was carried out in both positive and negative polarity. The positive ion mass spectra of TSILs showed sharp fragmented peaks for tertiaryalkyl amines at typical level and up to 10 ppm. The possible mechanism for different fragmentation pathways in positive polarity was discussed. 相似文献
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