Fast analysis of relevant contaminants mixture in commercial shellfish

One of the major challenges currently faced is to develop systematic ways of addressing chemical mixtures in environmental assessment. With this purpose, a simple, rapid, and sensitive method for the detection and quantification of a mixture of relevant contaminants in molluscs has been developed. The method is based on QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) and Ultra-High Performance Liquid Chromatography-High Resolution Mass Spectrometry (UHPLC-HRMS). It includes a mixture of 23 compounds formed by pesticides, endocrine disruptors and pharmaceuticals (metolachlor, simazine, desethylatrazine, atrazine, thiabendazole, diazinon, malathion, bentazone, MCPA, propanil, acetamiprid, imidacloprid, caffeine, bisphenol A, triclosan, triclocarban, methylparaben, ethylparaben, propylparaben, 1H-benzotriazole, sulfamethoxazole, venlafaxine and carbamazepine). The method was developed and validated in 4 different types of shellfish of high commercial interest such as mussel (Mytilus galloprovincialis), oyster (Crassostrea gigas), cockle (Cerastoderma edule) and razor shell (Solen marginatus). The mean percentage of recoveries obtained for all the compounds in each mollusc type (intra-specie) ranged from 96% to 107% showing the good performance of the method developed. The relative standard deviation was under 10% for the intra-day and 17% inter-day analyses. Method detection limits and method quantification limits were below 10 ng/g dry weight for all the species and compounds targeted. Finally, the method was applied to aquaculture samples, oysters and cockles, from Ebro Delta (Spain), after some episodes of mortality occurred in 2017. A high level of bisphenol A was detected in C. edule which may explain the mortality suffered by this organism. C. gigas presented low levels of metolachlor, bentazone, acetamiprid, and methylparaben.info:eu-repo/semantics/acceptedVersio

Bioaccessibility of contaminants of emerging concern in raw and cooked commercial seafood species: insights for food safety risk assessment.

Autoria na publicação: FABIOLA FOGAÇA

Pesticides in sediments of the Ebro River Delta cultivated area (NE Spain): Occurrence and risk assessment for aquatic organisms

Intense agricultural activities are performed in the Ebro River Delta (NE Spain) with extensive use of pesticides. Medium to highly polar pesticides have not been studied intensively in sediments despite its larger use in the recent years. This work aimed at assessing the occurrence of 69 pesticides, including medium to highly polar compounds, in sediments collected from drainage and irrigation channels of the Ebro River Delta during the main rice growing season. In addition, an environmental risk assessment was performed to evaluate the potential adverse effects to sediment-dwelling organisms with the risk quotient approach. A total of 24 pesticides were detected in sediments with bentazone and cypermethrin exhibiting high detection frequencies (79%) as well as high mean concentration levels (61.9 and 81.8 ng g−1 dw, respectively). Overall, the Alfacs bay, in the South of the delta, presented higher pesticide contamination than the Fangar bay, in the North. A similar pesticide distribution profile was observed in both bays, with oxadiazoles, organochlorines, pyrethroids, benzothiazinones and organophosphates as major, predominant classes. The presence of oxadiazon, pendimethalin and thifensulfuron methyl in the sediments may pose a moderate risk to sediment-dwelling organisms while bentazone, chlorpyrifos, and cypermethrin exhibited a potential high risk. Thus, the importance of the inclusion of medium to highly polar pesticides in the analysis of sediments is emphasized since some polar pesticides such as bentazone, imidacloprid, and thifensulfuron-methyl have been detected at concentrations that may pose a risk to aquatic organisms. Moreover, the co-occurrence of pesticides may potentially pose a high risk to sediment-dwelling organisms in 13 out of the 14 investigated locations. Finally, it could be concluded that the risk derived from the presence of pesticides in sediments must be assessed since some pesticides not detected at concerning levels in water, may pose a moderate/high risk in the sediments.info:eu-repo/semantics/publishedVersio