Validation of a simple and robust multi-residue gas chromatography-mass spectrometry method for the analysis of polycyclic aromatic hydrocarbons, phthalates and biocides in roofing material leachate and roof runoff

Abstract A multi-residue method for the determination of 16 polycyclic aromatic hydrocarbons (PAHs), biocides diuron (DIU), octylisothiazolinone (OIT) and mecoprop (MCPP), and phthalates bis(2-ethylhexyl) phthalate (DEHP) and diisodecyl phthalate (DIDP) in material leachate and roof runoff is presented. The method aims to keep sample pretreatment as simple as possible, not only to minimize sample contamination and sample losses, but also to have an environmental friendly and cost efficient method with low solvent consumption, in line with the principles of Green Analytical Chemistry. Solid phase extraction (SPE, C18) in combination with GC-MS was used for this purpose. A good separation and accurate detection for the majority of included analytes was obtained, resulting in overall low detection limits ranging between 0.1 ng/L and 18 µg/L in aqueous matrices. Furthermore, the addition of a surrogate standard containing three deuterated PAHs prior to SPE extraction was found to increase the method's repeatability. For the higher molecular weighted PAHs and phthalates, recovery was affected by the concentration level as higher recoveries were observed at lower spiking levels. Furthermore, also the matrix was found to affect the recovery of these higher molecular weighted components as the recoveries in roof runoff and material leachate were higher in comparison to the ones found in bidest water. Water solubility and the affinity to adsorb onto particles were hypothesized to play an important role. The multi-residue SPE-GC-MS method was found to be suitable for the quick and reliable analysis of material leachates and roof runoff samples.