The per- and polyfluoroalkyl substances (PFAS) targeted for analysis in blood may vary based on the specific concern in a given region or population. Some commonly analyzed PFAS range from short- to long-chain compounds (C4 – C10). The ultrashort-chain (USC) PFAS with carbon chain lengths of shorter than C4 have become a major concern due to their prevalence and high levels of occurrence in environmental aquatic systems.
Several studies have indicated a rapid increase in environmental concentration of USC PFAS, raising the concern of elevated human exposure. The measurement of USC PFAS in blood can not only monitor the human exposure but also provide a tool for studying the potential risks associated with USC PFAS exposure. However, the high polarity of ultrashort-chain PFAS poses a challenge to current analytical practices based on reversed-phase liquid chromatography due to insufficient chromatographic retention.
A unique method was developed to enable simultaneous biomonitoring of USC PFAS and commonly analyzed C4 to C10 compounds. The analytes in this study included C1 to C10 carboxylic acid and sulfonic acid PFAS, along with four alternative compounds: hexafluoropropylene oxide dimer acid (HFPO-DA), 4,8-dioxa-3H-perfluoro-nonanoic acid, 9-chlorohexadecafluoro-3-oxanonane-1-sulfonic acid, and 11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid.
Satisfactory retention was achieved for C1 to C3 compounds, including trifluoroacetic acid (TFA), perfluoropropanoic acid, trifluoromethanesulfonic acid, perfluoroethanesulfonic acid, and perfluoropropanesulfonic acid.
This study demonstrated that a polar-embedded, reversed-phase column allows for the simultaneous analysis ultrashort-chain and long-chain PFAS.
