Countermeasure for interfered monitoring ion of perfluorooctanesulfonic acid (PFOS) from intrinsic food samples based on LC-MS/MS analysis of per- and polyfluoroalkyl substances
Takahiro Takayama, A. Shingu, Sumire Kato, Ryosuke Nagatomo, Tomoaki Tsutsumi, Koichi Inoue
Abstract
This study aimed to investigate the risk of false liquid chromatography with tandem mass spectrometry (LC-MS/MS) detection (electrospray ionization-positive mode, m/z 499 > 80) of perfluorooctanesulfonic acid (PFOS) caused by interference peak from food matrices for the analysis of per- and polyfluoroalkyl substances (PFAS). A complete separation between PFOS and interference peaks was achieved using conventional analytical conditions of mobile phase based on C18 column with 5 mmoL L-1 ammonium acetate containing water/acetonitrile. Moreover, the interference chemical is identified to taurochenodeoxycholic acid from egg sample. Then, a variety of approaches have been used to quantify PFAS with C4-C9 perfluoro chain type for solid phase extraction using mixed standard (PFAC-MXC). The amounts of PFAS in certified fish paste were determined within the uncertainty level (95% confidence interval). Among the four types of foods (meat, vegetable, fish, and egg), these were well recovered (within around 80%–120%) with good reproducibility (RSD (%) < 15%). Our approach is suitable for quantifying PFAS with C4-C9 perfluoro chains type in food matrices.