2D-SDS PAGE	two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis
LC-MS	liquid chromatography coupled with mass spectrometry
ELISA	enzyme-linked immunosorbent assay
RPLC	reversed-phase liquid chromatography
ESI	electrospray ionization
QQQ	triple quadrupole
UHPLC	ultra-high-performance liquid chromatography
IS	internal standard
QCs	quality control
MRM	multiple reaction monitoring
LOD	limit of detection
LOQ	limit of quantification
Alb	human albumin
Lys	human lysozyme
Lact	human lactoferrin