PFAS stands for per- and poly-fluoroalkyl substances. They are hardly decomposed in the environment and contain substances that are subject to the Stockholm Convention on Persistent Organic Pollutants (POPs). Its persistence in the environment and accumulation in living organisms are concerned. HILICpak VT-50 2D, a polymer-based HILIC mode column, was used to analyze 9 kinds of PFAS and 3 kinds of haloacetic acids. VT-50 2D retains polar substances, which are not retained well by regular reversed-phase mode ODS columns. Thus, it is suitable for the analysis of PFAS, short-chain carbon compounds with high polarity. The effects of eluents with different acetonitrile and ammonium ratios were studied under isocratic mode. U-shaped trends were observed when the retention time (tR) was plotted against acetonitrile concentration. The below chromatograms were obtained using 70 % acetonitrile as eluent. PFPrA and DFA sample was prepared separately from the others to avoid the 37Cl peak interference of TCAA and MCAA.
Sample: 1 μL
Sample solution 1Â (in CH3OH/H2O=1/1)
PFOS, Perfluorooctanesulfonic acid 100 ng/mL
PFBS, Perfluorobutanesulfonic acid 100 ng/mL
TFMS, Trifluoromethanesulfonic acid 100 ng/mL
PFOA, Perfluorooctanoic acid 100 ng/mL
PFBA, Perfluorobutanic acid 100 ng/mL
PFPrA, Pentafluoropropionic acid 10 μg/mL
DFA, Difluoroacetic acid 10 μg/mL
TFA, Trifluoroacetic acid 10 μg/mL
HFIP, Hexafluoro-2-propanol 10 μg/mL
TCAA, Trichloroacetic acid 10 μg/mL
DCAA, Dichloroacetic acid 10 μg/mL
MCAA, Monochloroacetic acid 10 μg/mL
Sample solution 2Â (in CH3OH/H2O=1/1)
PFPrA, Pentafluoropropionic acid 10 μg/mL
DFA, Difluoroacetic acid 10 μg/mL
Column : Shodex HILICpak VT-50 2D (2.0 mm I.D. x 150 mm) Eluent : 50 mM CH3COONH4 aq./CH3CN=60/40, 50/50, 40/60, 30/70, 20/80 Flow rate : 0.2 mL/min Detector : ESI-MS (SIM Negative) Column temp. : 40 °C
