Evaluation of mutual interference between bovine α-lactalbumin peptide and its isotope-labeled peptide in whey protein analysis using liquid chromatography-tandem mass spectrometry

摘要

Highlights?α-Lactalbumin peptide was analyzed by LC–MS using isotope-labeled internal standard.?Mutual interference between peptides and their isotope-labeled internal standards was examined systematically.?A simple strategy was proposed to suppress the mutual interference.AbstractInternal standard (IS) method is commonly used to correct the matrix effect of samples in the liquid chromatography-tandem mass spectrometric (LC–MS/MS) analysis of whey proteins. However, the presence of mutual interference between some peptides and their isotope-labeled peptides distorts the MS signals, requiring a fundamental evaluation to understand the phenomenon of signal variations. In this study, a simple strategy is proposed to evaluate the effects of sample pretreatment, materials and dilution of solutions on the MS signals of α-lactalbumin (VGINYWLAHK) and β-lactoglobulin peptides using two typical LC–MS/MS systems, Q-Trap and Q-Orbitrap. The strategy adapts the experimental MS data to optimize methods, thus pro