Determination of C(5)-C(12) perfluoroalkyl carboxylic acids in river water samples in the Czech Republic by GC-MS after SPE preconcentration.

A method employing solid phase extraction followed by gas chromatography-mass spectrometry with negative chemical ionization has been developed for determination of ultratrace concentrations of perfluoroalkyl carboxylic acids in river water. The effects of the experimental parameters, such as the pH, additions of NaCl and an ion-pairing agent (tetraethylammonium bromide) and the kind of the elution agent, on the efficiency of the test acid extraction have been studied. The analyte extraction recoveries and the limits of detection and determination have been found.

A fast derivatization procedure for gas chromatographic analysis of perfluorinated organic acids.

A rapid and simple derivatization procedure has been developed for gas chromatographic determination of perfluorinated organic acids (PFCAs, C(6)-C(12)), using isobutyl chloroformate (IBCF) to convert the acids into the more volatile isobutyl esters, under catalysis by pyridine. The procedure was optimized in an acetonitrile medium and applied to GC techniques with electron-capture detection (GC-ECD) and mass spectrometry with electron-impact ionization (GC-EI-MS); for the sake of comparison, HPLC with electrospray-ionization MS (HPLC-ESI(-)-MS) was also tested. The LOD and LOQ values obtained for these three techniques were compared, and the lowest LODs were obtained with GC-ECD (0.