Determination of organic contaminants in L'Albufera Natural Park using microporous polyethylene tube passive samplers: An environmental risk assessment.

L'Albufera Natural Park (Valencia, Spain) is a protected wetland of international significance that provides critical habitats to endemic and threatened bird and plant species. This study aims to use multiple cross-validation techniques to generate an accurate estimation of the environmental risk of organic contaminants (OCs) in an internationally important coastal wetland, to identify compounds of concern and their potential sources and risk factors. Microporous polyethylene tube (MPT) passive samplers were deployed at 12 locations across L'Albufera Natural Park with concurrent grab samples collected. A subset of MPT samplers were also analysed by an additional laboratory in Australia to widen the range of contaminants and assess interlaboratory reproducibility of results. Forty-three pesticides, 20 pharmaceuticals and personal care products (PPCPs), 20 per-and polyfluoroalkyl substances (PFAS) and 4 organophosphorus flame retardants (OPFRs) were detected in the MPT samplers. The fungicides tebuconazole and difenoconazole were detected at the highest concentrations in passive samplers (maximum concentrations, 153 ng sampler-1 and 106 ng sampler-1, respectively). Several other pesticides were detected in all locations (mean concentrations >1 ng sampler-1). The compounds fenamiphos, propyzamide, difenoconazole, propiconazole, metsulfuron methyl, sodium bis (perfluorohexyl) phosphinate (6:6 PFPiA), 6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB), 6:2 fluorotelomersulfonate (6:2 FTS), citalopram desmethyl and citalopram were reported in the wetland for the first time. Spatial distribution analysis revealed higher pesticide concentrations in the North of L'Albufera. A risk quotient (RQ) analysis showed that ibuprofen is of concern in the area. Overall, the MPT sampling approach is promising as a risk assessment tool for better understanding the transport and fate of OCs in protected areas.

Estimation of per- and poly-fluoroalkyl substances mass loads in the Danube River using passive sampling.

As Europe's second longest river, the Danube is an important water source for drinking water and irrigation for many countries, before discharging into the Black Sea in the East. Per- and poly-fluoroalkyl substances (PFAS) have been observed over the last two decades in concentrations exceeding the European Union's drinking water guidelines for total sum of 20 select PFAS of 0.1 µg L-1. Their presence is a result of current and historical use and high environmental persistence, necessitating their monitoring for human risk assessments. The aim of this study is to use recently developed passive sampling technology to calculate time-integrated water concentrations and mass loads of 11 select PFAS at 9 sites along the Danube River. Results indicate ∑11 PFAS concentrations in the range of 9.3-29.6 ng L-1 were not in exceedance of EU drinking water guidelines, but perfluorooctanesulfonic acid (PFOS) was in exceedance of the environmental quality standard (0.65 ng L-1) at all sampling locations. The highest ∑11 PFAS mass loads were observed at Ruse (9.5 kg day-1) and Budapest (6.3 kg day-1), believed to be driven by proximity to industrial facilities and large populations (urban runoff). Finally, we estimate 4.9 kg of total PFAS (∑11 PFAS) were delivered to the Black Sea daily over Summer 2019.

Untargeted and Targeted Metabolomic Profiling of Australian Indigenous Fruits.

Selected Australian native fruits such as Davidson's plum, finger lime and native pepperberry have been reported to demonstrate potent antioxidant activity. However, comprehensive metabolite profiling of these fruits is limited, therefore the compounds responsible are unknown, and further, the compounds of nutritional value in these native fruits are yet to be described. In this study, untargeted and targeted metabolomics were conducted using the three fruits, together with assays to determine their antioxidant activities. The results demonstrate that targeted free and hydrolysed protein amino acids exhibited high amounts of essential amino acids. Similarly, important minerals like potassium were detected in the fruit samples. In antioxidant activity, Davidson's plum reported the highest activity in ferric reducing power (FRAP), finger lime in antioxidant capacity (ABTS), and native pepperberry in free radical scavenging (DPPH) and phosphomolybdenum assay. The compounds responsible for the antioxidant activity were tentatively identified using untargeted GC×GC-TOFMS and UHPLC-QqQ-TOF-MS/MS metabolomics. A clear discrimination into three clusters of fruits was observed using principal component analysis (PCA) and partial least squares (PLS) analysis. The correlation study identified a number of compounds that provide the antioxidant activities. GC×GC-TOFMS detected potent aroma compounds of limonene, furfural, and 1-R-α-pinene. Based on the untargeted and targeted metabolomics, and antioxidant assays, the nutritional potential of these Australian bush fruits is considerable and supports these indigenous fruits in the nutraceutical industry as well as functional ingredients for the food industry, with such outcomes benefiting Indigenous Australian communities.