We present here a novel and highly sensitive ion-pair hydrophilic interaction chromatography-tandem mass spectrometry (IP-HILIC-MS/MS) method for quantitation of highly polar acid metabolites like adenine nucleotides. A mobile phase based on diethylamine (DEA) and hexafluoro-2-isopropanol (HFIP) and an aminopropyl (NH2) column were applied for a novel chromatographic separation for the determination of AMP, ADP and ATP in biological matrices. This novel IP-HILIC mechanism could be hypothesized by the ion-pairing reagent (DEA) in the mobile phase forming neutral and hydrophilic complexes with the analytes of polar organic acids.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
May 2012
Measurement of endogenous epinephrine (E) and norepinephrine (NE) in human plasma is very challenging due to lower endogenous concentrations as compared with animal plasma. An LC-MS/MS in combination with alumina-based SPE and derivatization procedure was validated for the measurement of E and NE in human plasma with acceptable intra-day and inter-day accuracy and precision. Sample was extracted with semi-automated alumina 96-well solid phase extraction (SPE) cartridge.
View Article and Find Full Text PDFThe chromatographic performance of fused-core (superficially porous) HPLC packing materials was compared with conventional fully porous particle materials for LC-MS/MS analysis of two pharmaceuticals in rat plasma. Two commercially available antidepressants, imipramine and desipramine, were assayed using a conventional analytical C(18) column (5 microm, 2.0 mm x 30 mm) and a fused-core C(18) column (2.
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