Analytical progress and challenges for the detection of oxygenated polycyclic aromatic hydrocarbon transformation products in aqueous and soil environmental matrices: A review

Abstract

Over the past 20 years, a growing body of research has raised concerns about the toxicity, fate, and transport of oxygenated transformation products of polycyclic aromatic hydrocarbons. Research targeting these diverse compounds in soil and water systems has been challenged by a lack of standard analytical techniques and suitable reference materials. However, recent efforts towards the consolidation of traditional analytical techniques as well as the development of novel approaches to improve sample preparation and hyphenated instrumental techniques show promise. This review discusses progress and challenges for both trends in analytical method development, and makes recommendations for supporting oxygenated PAH research.

Recovery of polycyclic aromatic hydrocarbons and their oxygenated derivatives in contaminated soils using aminopropyl silica solid phase extraction

“…OPAH concentrations in Soil 1 and 2 were in line with those observed for other industrial soils with high-range and mid-range contamination levels, respectively (Arp et al, 2014). Comparison for OHPAH was somewhat more difficult due to the paucity of studies reporting concentrations of these compounds, but in general OHPAH concentrations here tended to be higher than those reported across soils of varying land-use histories (Pulleyblank et al, 2019). Soil 2 indicated levels that are similar to those evaluated for ERM-CC013a, obtained from a former gasworks sites in Berlin (Bandowe and Wilke, 2010), while Soil 1 indicated levels substantially higher levels than have previously been reported.…”

“…By tracking the amount of surrogate lost (or gained), the recovery of related target analytes can be estimated, and/or final target analyte concentrations may be adjusted or "corrected" for losses/ gains/ matrix effects introduced during sample processing. Although the availability of deuterated OPAH internal or surrogate standards is improving, these compounds are not widely available, and there is uncertainty in their best use during OPAH analysis (Pulleyblank et al, 2019). In the meantime, more readily available deuterated PAH are sometimes used as surrogates estimating OPAH recovery or correcting for losses during sample preparation (Obrist et al 2015).…”

“…While a greater understanding of transformation products with a range of chemistries could improve decision making at contaminated sites (Lundstedt et al, 2007), this research is currently hampered by a lack of standard protocols for identifying and quantifying these compounds in soils (Pulleyblank et al, 2019, for extended review and references). Effort has been made towards routinizing OPAH analysis in soils (Lundstedt et al, 2014), with the most typical approach involving extraction of the soil with dichloromethane, hexane, or hexane/acetone, followed by a clean-up or fractionation step over silica using column chromatography or solid phase extraction (SPE) in order to remove interferents and/or fractionate PAH and OPAH.…”

“…Fractionation also offers the opportunity for analysing different compound classes using, e.g., different derivatization or instrumental methods. However, only a few studies have described methods for the separation of OHPAH and COOHPAH alongside PAH and OPAH in whole-soil extracts (Bandowe and Wilcke, 2010;Chibwe et al, 2015;Letzel et al, 2001;Meyer et al, 1999), and there has been little broader uptake in the use of these methods (Pulleyblank et al 2019). Further work is needed to address specific limitations of available methods such as uncertain quantitative performance (Chibwe et al, 2015;Meyer et al, 2013), uncertainty in the best application of surrogate recovery compounds, low recovery of OHPAH and COOHPAH (Bandowe and Wilcke, 2010), and/or the amount of material and complexity of the methods (Chibwe et al, 2015;Meyer et al, 1999).…”

“…Existing methods targeting one or more class of oxygenated PAH in crude soil extracts have utilized silica, alumina, polymeric, or strong base sorbents, sometimes in combination (Pulleyblank et al, 2019). To date, the utility of weak base aminopropyl silica for the fractionation of PAH, OPAH, OHPAH and COOHPAH from soil extracts has not been investigated.…”