PAH Analysis of Sediment Pore Water (SPME/GCMS-SIM)
Total PAH concentrations in sediment are generally recognized in the literature to be poor predictors of benthic invertebrate toxicity. Pore water analysis provides a better indication; however, the direct measurement of PAH concentrations in pore water has traditionally been very challenging.
Alpha Analytical utilizes ASTM Method D7363-13a: Determination of Parent and Alkyl Polycyclic Aromatics in Sediment Pore Water Using Solid-Phase Micro-Extraction and Gas Chromatography/Mass Spectrometry in Selected Ion Monitoring Mode, which provides a viable option with minimal pore water volume required for a sample aliquot to be obtained under representative conditions from a small amount of sediment.
This method is designed to measure dissolved PAH concentrations in sediment pore water. The pore water is separated from the bulk sediment by centrifugation and is then subjected to a flocculation procedure to assure that only the dissolved fraction is determined. The sample is then analyzed by GC/MS-SIM with a solid phase micro-extraction (SPME) sample introduction technique. Alpha can determine all EPA Ecological Monitoring & Assessment Program (EMAP) 34 PAH compounds utilizing this methodology with reporting limits as low as 0.06 ug/L.