Determination of (S)-(+)- and (R)-(-)-ibuprofen enantiomers in human plasma after chiral precolumn derivatization by reversed-phase LC–ESI-MS/MS

Bioanalysis ◽  
2012 ◽  
Vol 4 (24) ◽  
pp. 2909-2927 ◽  
Author(s):  
Primal Sharma ◽  
Swati Guttikar ◽  
Gajendra Solanki ◽  
Daxesh P Patel ◽  
Pranav S Shrivastav
2019 ◽  
Vol 411 (6) ◽  
pp. 1239-1251 ◽  
Author(s):  
Michaela Chocholoušková ◽  
Robert Jirásko ◽  
David Vrána ◽  
Jiří Gatěk ◽  
Bohuslav Melichar ◽  
...  

1995 ◽  
Vol 13 (2) ◽  
pp. 159-164 ◽  
Author(s):  
Greg La Follette ◽  
Anura L. Jayewardene ◽  
Ananda K. Seneviratne ◽  
Emil T. Lin ◽  
John G. Gambertoglio

2020 ◽  
Vol 20 (13) ◽  
pp. 1053-1059
Author(s):  
Mahmoud M. Sebaiy ◽  
Noha I. Ziedan

Background: Allergic diseases are considered as the major burden on public health with increased prevalence globally. Histamine H1-receptor antagonists are the foremost commonly used drugs in the treatment of allergic disorders. The target drug in this study, loratadine, belongs to this class of drugs and its biometabolite desloratadine which is also a non-sedating H1 receptor antagonist with anti-histaminic activity being 2.5 to 4 times greater than loratadine. This study aimed to develop and validate a novel isocratic Reversed-phase High-Performance Liquid Chromatography (RP-HPLC) method for rapid and simultaneous separation and determination of loratadine and its metabolite, desloratadine in human plasma. Methods: The drug extraction method from plasma was based on protein precipitation technique. The separation was carried out on a Thermo Scientific BDS Hypersil C18 column (5μm, 250 x 4.60 mm) in a mobile phase of MeOH: 0.025M KH2PO4 adjusted to pH 3.50 using orthophosphoric acid (85: 15, v/v) at an ambient temperature. The flow rate was maintained at 1 mL/min and maximum absorption was measured using the PDA detector at 248 nm. Results: The retention times of loratadine and desloratadine in plasma samples were recorded to be 4.10 and 5.08 minutes, respectively, indicating a short analysis time. Limits of detection were found to be 1.80 and 1.97 ng/mL for loratadine and desloratadine, respectively, showing a high degree of sensitivity of the method. The method was then validated according to FDA guidelines for the determination of the two analytes in human plasma. Conclusion: The results obtained indicate that the proposed method is rapid, sensitive in the nanogram range, accurate, selective, robust and reproducible compared to other reported methods.


2020 ◽  
Vol 10 (2) ◽  
pp. 122-129
Author(s):  
Haoyu Lv ◽  
Yabin Tang ◽  
Fan Sun ◽  
Shimin An ◽  
Xinjie Yang ◽  
...  

Background:In recent years, more and more researches have shown that neurotransmitters can also be synthesized and released by peripheral non-neural cells. However, specificity and high sensitivity detection means were required for confirming ESCs autocrine glutamate and γ - aminobutyric acid (GABA). Glutamate and GABA are water-soluble and polar compounds which cannot be retained on a reversed phase C18 column, and their contents are often at a trace level. On the other hand, the biological matrix such as cell culture fluid contains a large number of amino acids, vitamins, carbohydrates, inorganic ions and other substances. Therefore, the main problem is the selection of the chromatographic column to avoid matrix interference.Objective:To establish a rapid and reliable method for the simultaneous determination of glutamate and GABA released from embryonic stem cells based on analytical chemistry.Methods:Glutamate and GABA released from mouse embryonic stem cells were determined on the basis of hydrophilic interaction chromatography coupled with electrospray ionization tandem Mass Spectrometry (HILIC- ESI- MS/MS), using isotope internal standards and substitution matrix method.Results:Undifferentiated embryonic stem cells autocrine glutamate and GABA and will reach releasing- reuptacking dynamic equilibriums at different time points. In contrast, neither glutamate nor GABA releasing could be detected from the MEFs, indicating the specificity release of the mESCs in the applied analytic method.Conclusion:A novel, simple, sensitive, selective and quantitative method was developed for determination of the glutamate and GABA from mouse embryonic stem cells.


2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Vita Giaccone ◽  
Giuseppe Polizzotto ◽  
Andrea Macaluso ◽  
Gaetano Cammilleri ◽  
Vincenzo Ferrantelli

The aim of our present work was the development of a rapid high-performance liquid chromatography method with electrospray ionization and tandem mass spectrometry detection (LC-ESI-MS/MS) for the determination of several corticosteroids in cosmetic products. Corticosteroids are suspected to be illegally added in cosmetic preparations in order to enhance the curative effect against some skin diseases. Sample preparation step consists in a single extraction with acetonitrile followed by centrifugation and filtration. The compounds were separated by reversed-phase chromatography with water and acetonitrile (both with 0.1% formic acid) gradient elution and detected by ESI-MS positive and negative ionization mode. The method was validated at the validation level of 0.1 mg kg−1. Linearity was studied in the 5–250 μg L−1 range and linear coefficients (r2) were all over 0.99. The accuracy and precision of the method were satisfactory. The LOD ranged from 0.085 to 0.109 mg kg−1 and the LOQ from 0.102 to 0.121 mg kg−1. Mean recoveries for all the analytes were within the range 91.9–99.2%. The developed method is sensitive and useful for detection, quantification, and confirmation of these corticosteroids in cosmetic preparations and can be applied in the analysis of the suspected samples under investigation.


Lipids ◽  
2011 ◽  
Vol 47 (2) ◽  
pp. 209-226 ◽  
Author(s):  
M. Athar Masood ◽  
Raghavendra P. Rao ◽  
Jairaj K. Acharya ◽  
Josip Blonder ◽  
Timothy D. Veenstra

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