“…Additional gas phase separation with ion mobility, such as high-field asymmetric waveform ion mobility spectrometry[ 32 ], and different mass spectrometry acquisition techniques, such as BoxCar and DIA [ 37 , 38 ], have been employed to improve both HCP identification and quantification. Several PSDEs, including LPLA2 (PLA2G15, phospholipase A2, group XV), LPL (lipoprotein lipase), CES (liver carboxylesterase), LIPA (lysosomal acid lipase), PPT1 (palmitoyl-protein thioesterase 1), and SIAE (sialate o-acetylesterase) have been identified by TABP and have shown to have a direct impact on PS-80 or PS-20 degradation in biotherapeutics [ 15 , 26 , 27 , 33 , 39 ]. Drawbacks of these extensive sample preparation and LC–MS analytical approaches include reduced testing throughput and potential HCP loss, and hence impaired assay robustness.…”