scholarly journals Development of a novel microextraction by packed sorbent-based approach followed by ultrahigh pressure liquid chromatography as a powerful technique for quantification phenolic constituents of biological interest in wines

2012 ◽  
Vol 1229 ◽  
pp. 13-23 ◽  
Author(s):  
João Gonçalves ◽  
Berta Mendes ◽  
Catarina L. Silva ◽  
José S. Câmara
Keyword(s):  
Liquid Chromatography ◽  
Ultrahigh Pressure ◽  
Powerful Technique ◽  
Microextraction By Packed Sorbent ◽  
Biological Interest ◽  
Phenolic Constituents ◽  
Packed Sorbent

scholarly journals Determination and Pharmacokinetics of Omeprazole Enantiomers in Human Plasma and Oral Fluid Utilizing Microextraction by Packed Sorbent and Liquid Chromatography-Tandem Mass Spectrometry

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Hytham Ahmed ◽  
Abdel-Aziz Wahbi ◽  
Hatem Elmongy ◽  
Ahmad Amini ◽  
Hirsh Koyi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Oral Fluid ◽  
Tandem Mass ◽  
Plasma Samples ◽  
Microextraction By Packed Sorbent ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass ◽  
Packed Sorbent

In the present work, the determination of omeprazole (OME) enantiomers in oral fluid and plasma samples was carried out utilizing microextraction by packed sorbent (MEPS) and liquid chromatography-tandem mass spectrometry. A chiral column with cellulose-SB phase was used for the first time for enantiomeric separation of OME with an isocratic elution system using 0.2% ammonium hydroxide in hexane-ethanol mixture (70 : 30, v/v) as the mobile phase. OME enantiomers were determined utilizing a triple quadrupole tandem mass spectrometer in positive ion mode (ESI+) monitoring mass transitions: m/z 346.3 ⟶ 198.0 for OME and m/z 369.98 ⟶ 252.0 for internal standard. The limits of detection and quantification of the present method for both enantiomers were 0.1 and 0.4 ng/mL, respectively. The method validation provided good accuracy and precision. The matrix effect factor was less than 5%, and no interfering peaks were observed. The interday precision values ranged from 2.2 to 7.5 (%RSD), and the accuracy of determinations varied from −9.9% to 8.3%. In addition, the pharmacokinetics (PK) of omeprazole enantiomers in healthy subjects after a single oral dose was investigated. (S)-Enantiomers showed higher levels than (R)-enantiomers throughout 24 h. It was found that the mean maximum concentrations of (R)- and (S)-omeprazole in plasma samples were about two times higher than in oral fluid.

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