Method development for simultaneous analyses of polycyclic aromatic hydrocarbons and their nitro-, oxy-, hydroxy- derivatives in sediments

Abstract

It is important to establish an available analytical method for polycyclic aromatic hydrocarbons (PAHs), nitrated PAHs (nitro-PAHs), oxygenated forms of PAHs (oxy-PAHs), and hydroxy-PAHs (OH-PAHs) in sediment samples due to the fact that they co-exist in various environmental mediates, particularly in sediment. In this study, an analytical method has been developed and validated for the quantification of PAHs, nitro-PAHs, oxy-PAHs, and OH-PAHs in sediment samples. The sediment samples were extracted by accelerated solvent extraction and cleaned up with SPE alumina-n combining with aminopropyl cartridges. The extracts were further fractionated by using different solvents. The fractionated extracts were analyzed via gas chromatography of single and triple quadrupole mass spectrometry in the electron ionization and negative ion chemical ionization with selective ion monitoring and selective reaction monitoring mode and liquid chromatography-triple quadrupole mass spectrometry. Each group of analytes was determined by different instrument modes such as GC-EI-SIM for PAHs, GC-NICI-SRM for nitro-PAHs, GC-EI-SRM for the oxy-PAHs and LC-ESI-MS/MS for OH-PAHs. A total of 44 analytes (16 PAHs, 14 nitro-PAHs, 9 oxy-PAHs, and 5 OH-PAHs) and 6 deuterated surrogates were performed. Most of recovery percentage varied from 52.8% up to 114.1% for the targeted analytes verified at three concentration levels (100 ng/g, 400 ng/g and 1000 ng/g for PAHs and 10 ng/g, 50 ng/g and 400 ng/g for their derivatives). The repeatability determined by the relative standard deviation percentage of triplicate trials was less than 10% for most analytes. The limit of detection ranged from 0.01 to 0.02 ng/g for PAHs, 0.002–0.067 ng/g for nitro-PAHs, 0.01–0.1 ng/g for oxy-PAHs, and 0.003–0.006 ng/g for OH-PAHs. Most of the compounds were detectable in the sediments collected from a local River, which illustrates the developed method could be a practical and suitable technique for detection of PAHs and their derivatives in real sediment samples.