Investigation of microbore UPLC and nontraditional mobile phase compositions for bioanalytical LC-MS/MS (original) (raw)
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■ ■ Increased LC-MS system operating time and prolonged column life due to reduction in fouling INTRODUCTION Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) is one of the most widely used techniques employed to quantify analytes in biological samples. Endogenous phospholipids in such samples complicate the analysis. Phospholipids cause powerful matrix effects1 where the analyte MS signals are suppressed or enhanced. This causes variation in analyte peak areas and therefore the reported analyte concentrations when those peaks overlap the region where the phospholipids elute. Phospholipids can also strongly adhere to the LC stationary phase.2 Their presence on the chromatographic column can change the selectivity and retention of the analytes. Eventually, the column becomes saturated with phospholipids and the excess bleeds off continuously. This causes matrix effects, regardless of the analyte elution time. This is most problematic with the short narrow columns f...