Determination of organic priority pollutants in the low nanogram-per-litre range in water by solid-phase extraction disk combined with large-volume injection/gas chromatography-mass spectrometry.

Polybrominated diphenyl ethers, polychlorinated biphenyls, polycyclic aromatic hydrocarbons and organochlorine pesticides in the low nanogram-per-litre range in water were enriched by solid-phase extraction (SPE) disks and their concentration determined by large-volume injection/gas chromatography-mass spectrometry (LVI/GC-MS). One advantage of using SPE disks in comparison with SPE cartridges is that suspended particulate matter (SPM) does not have to be separated prior to the enrichment step, which saves time and effort. To increase the sensitivity of the method, the SPE disk procedure was combined with LVI/GC-MS, which has not been reported so far for water analysis. The method was calibrated in ranges from 0.25 to 2.5 ng/L and from 2.5 to 25 ng/L. The average recovery was 76% at an analyte concentration of 2.5 ng/L. The limits of quantification, defined at a signal-to-noise ratio of 6:1, reach from 0.1 to 24.0 ng/L and are up to 400 times lower than previously reported in water analysis. By the developed SPE/LVI/GC-MS method, it is possible to investigate the whole water sample without prior separation of the SPM within 2 h including GC-MS analysis.