Effects of UV filter 4-methylbenzylidene camphor during early development of Solea senegalensis Kaup, 1858.

The inclusion of organic UV filters in personal care products (PCPs) has increased in recent years. 4-Methylbenzylidene camphor (4MBC) is one of the most used UV filters, and thus it is commonly found in aquatic ecosystems, with proved negative effects on aquatic organisms. Effects on early life stages of marine vertebrates are largely unknown. Therefore, the main goal of this work was to evaluate 4MBC effects on Senegalese sole (Solea Senegalensis Kaup, 1858) larvae at different levels of biological organization. S. senegalensis were exposed to increasing concentrations of 4MBC from egg stage until 96 h. Mortality, growth, malformations, behaviour and biochemical responses, including enzymatic biomarkers were studied. The exposure to 4MBC until 96 h post-fertilization (hpf) induced mortality and malformations in a dose-response manner. Besides, reduced growth with increasing concentrations was observed. The exposure to 4MBC also caused alterations on behaviour, including overall lower swimming time during light and dark periods. Biomarker alterations caused by 4MBC included imbalance of neurotransmission related endpoints (increased acetylcholinesterase activity) and decreased activity of enzymes related to anaerobic metabolism (lower cellular lactate dehydrogenase activity) at the lower concentrations tested. Furthermore, our results suggest that 4MBC do not induce oxidative stress in S. senegalensis larvae, since catalase and lipid peroxidation levels were not significantly altered by 4MBC. S. senegalensis revealed to be a good model species for vertebrate animal testing in the marine environment. Sub-lethal concentrations of 4MBC induced toxic effects at all organizational levels. Swimming behaviour was a sensitive endpoint and showed that exposure to 4MBC causes impairment on response to light stimulus which is possibly linked with the observed imbalances on cholinesterase activity in larvae. Conservation concerns along distribution range of S. senegalensis should consider that increasing levels of UV filters in marine environment might have impact on the ecology of the species.

Determination of UV filters in both soluble and particulate fractions of seawaters by dispersive liquid-liquid microextraction followed by gas chromatography-mass spectrometry.

An analytical method to determine the total content (i.e., not only in the soluble fraction but also in the particulate one) of eight commonly used UV filters in seawater samples is presented for the first time. Dispersive liquid-liquid microextraction (DLLME) is used as microextraction technique to pre-concentrate the target analytes before their determination by gas chromatography-mass spectrometry (GC-MS). In order to release the UV filters from the suspended particles an ultrasound treatment is performed before DLLME. The ultrasound treatment time was studied in order to achieve a quantitative lixiviation of the target analytes. The type and volume of both disperser and extraction solvent, the sample volume, the pH and the ionic strength involved in the DLLME have been optimized to provide the best enrichment factors. Under the optimized conditions, the method was successfully validated showing good linearity, enrichment factors between 112 and 263 depending on the analyte, limits of detection and quantification in the low ng L(-1) range (10-30 ng L(-1) and 33-99 ng L(-1), respectively) and good intra- and inter-day repeatability (RSD <15%). No significant matrix effects were found. Finally, the method was satisfactorily applied to the analysis of three seawater samples from different origin. Results showed significant amounts of UV filters in the particulate fraction that would have been ignored if only the soluble fraction had been considered. This fact shows that the UV filters are also accumulated in the suspended particles contained in water, what should be taken into account from an environmental standpoint.