Analysis of 18 perfluorinated compounds in river waters: comparison of high performance liquid chromatography-tandem mass spectrometry, ultra-high-performance liquid chromatography-tandem mass spectrometry and capillary liquid chromatography-mass spectrometry.

In this work, the performance of ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and capillary liquid chromatography-mass spectrometry (CLC-MS) has been studied for the analysis of eighteen perfluorinated compounds in water samples. UHPLC-MS/MS and CLC-MS analysis were carried out using a Zorbax C-18 column (50 mm × 2.1 mm, 1.8 μm) and a Zorbax SB-C18 column (150 mm × 0.5 mm, 3.5 μm), respectively, in gradient elution mode with a mobile phase of ammonium formate and methanol. Both techniques were compared with conventional LC-MS/MS in terms of speed, sensitivity, selectivity and resolution. Water samples were extracted by solid phase extraction (SPE). Mean absolute recoveries at two concentration levels, 6 and 60 ng L⁻¹, calculated from the eighteen compounds were: 77 ± 12(s) and 82 ± 12(s), respectively. Relative standard deviation (RSD) was lower than 16% for each perfluorinated compound. The results obtained showed that UHPLC-MS/MS and CLC-MS allow the determination of perfluorinated compounds in water samples with satisfactory sensitivity and resolution and reduced analysis time. Therefore, both techniques were employed for the analysis of water samples to determine the target analytes at low concentration levels and with lower analysis times than using HPLC-MS/MS. Similar statistical values were obtained from both techniques at 95% confidence level. Several compounds have been detected, but perfluorooctanoic acid (PFOA) (171 ng L⁻¹ and 148 ng L⁻¹ by UHPLC-MS/MS and CLC-MS, respectively) showed the highest concentration.