Unraveling the Oligomer‐specific Uptake Dynamics of PEG600 With 9–18 Subunits in HepG2 Cells by Ultra‐High‐Performance Liquid Chromatography‐Tandem Mass Spectrometry Coupled With Ammonium Adduct Strategy to Enhance Sensitivity

> 0.99) across 10-1000 ng/mL for PEG600 oligomers (n = 9-18). PEG600 oligomers (n = 9-18) internalization in HepG2 cells was quantified by the validated UHPLC-MS/MS method. PEG600 polymers with 9-18 subunits could be absorbed into HepG2 cells with a small quantity (less than 0.04%). The cytotoxicity study suggested that the half-maximal inhibitory concentration of PEG600 on HepG2 cells is 31.42 mg/mL. PEG600 oligomers demonstrated negligible anti-proliferative effects in HepG2 hepatocytes. This study could provide analytical techniques and critical reference data for cytotoxicity and whole cellular uptake profiles of PEG600 polymers with 9-18 subunits in HepG2 cells. This work establishes an analytical framework for assessing the cytotoxicity and cellular uptake kinetics of PEG600 oligomers (n = 9-18) in HepG2 cells.