Sara Ramos

Advances in analytical methods and occurrence of organic UV-filters in the environment - A review

UV-filters are a group of compounds designed mainly to protect skin against UVA and UVB radiation, but they are also included in plastics, furniture, etc., to protect products from light damage. Their massive use in sunscreens for skin protection has been increasing due to the awareness of the chronic and acute effects of UV radiation. Some organic UV-filters have raised significant concerns in the past few years for their continuous usage, persistent input and potential threat to ecological environment and human health. UV-filters end up in wastewater and because wastewater treatment plants are not efficient in removing them, lipophilic compounds tend to sorb onto sludge and hydrophilics end up in river water, contaminating the existing biota. To better understand the risk associated with UV-filters in the environment a thorough review regarding their physicochemical properties, toxicity and environmental degradation, analytical methods and their occurrence was conducted. Higher UV-filter concentrations were found in rivers, reaching 0.3mg/L for the most studied family, the benzophenone derivatives. Concentrations in the ng to μg/L range were also detected for the p-aminobenzoic acid, cinnamate, crylene and benzoyl methane derivatives in lake and sea water. Although at lower levels (few ng/L), UV-filters were also found in tap and groundwater. Swimming pool water is also a sink for UV-filters and its chlorine by-products, at the μg/L range, highlighting the benzophenone and benzimidazole derivatives. Soils and sediments are not frequently studied, but concentrations in the μg/L range have already been found especially for the benzophenone and crylene derivatives. Aquatic biota is frequently studied and UV-filters are found in the ng/g-dw range with higher values for fish and mussels. It has been concluded that more information regarding UV-filter degradation studies both in water and sediments is necessary and environmental occurrences should be monitored more frequently and deeply.

A review of organic UV-filters in wastewater treatment plants

UV-filters are a group of compounds which have been massively used in the past years due to the recent concerns with sunburns, premature skin ageing and the risk of developing skin cancer, related to sun exposure. At the moment, these compounds have been identified by the scientific community as emerging pollutants, due to their persistence in the environment, potential to accumulate in biota and potential threat as endocrine disruptors. At some point, the majority of sunscreens will find their way into wastewater (due to bathing and washing activities) and because wastewater treatment plants (WWTPs) are not able to remove and/or degrade them, consequently they find their way into rivers, lakes and ocean, so it is not surprising that UV-filters are found in the environment. Therefore, wastewater treatment plants should be the focus of the scientific community aiming to better understand the fate of the UV-filters and develop new technologies to remove them from wastewater and sludge. This review, aims to provide the current state of the art in the occurrence and fate of UV-filters in wastewater treatment plants and how the technologies that are being used are successfully removing these compounds from both wastewater and sludge.

An analytical multi-residue approach for the determination of semi-volatile organic pollutants in pine needles

Vegetation (and pine needles in particular) has been widely used as an alternative to other conventional sampling devices to assess the atmospheric presence of semi-volatile organic contaminants (SVOCs). While most analytical procedures developed focus only on one or two chemical classes, this this work intends to establish a multi-component protocol to quantify brominated flame-retardants (BFRs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polynuclear aromatic hydrocarbons (PAHs) and one class of contaminant of emerging concern, the synthetic musks fragrances (SMCs). Pine needles extracts were obtained by ultrasonic solvents extraction (USE), and different cleanup approaches using solid-phase extraction (SPE) employing combinations of sorbents and solvents as well as gel permeation chromatography (GPC) were tested. SPE with alumina followed by GCP yielded the best results, with average recoveries over 80%. The application of the method under field conditions was proven by the analysis of naturally contaminated samples from 3 sites of different potential exposure (remote, rural and urban). The total detected concentrations ranged from 0.45 to 0.87 ng g(-1) dry weight (dw) for BFRs, 0.35 to 1.01 ng g(-1) (dw) for PCBs, 0.36 to 12.2 ng g(-1) (dw) for HCB, 245.7 to 967.8 ng g(-1) (dw) for PAHs and 20.7 to 277.5 ng g(-1) (dw) for SMCs. This methodology is a viable approach for the simultaneous analysis of five different classes of atmospheric pollutants employing less analytical efforts. Moreover, to the authors best knowledge, this is also the first time vegetation is employed in the detection of SMCs.

Solvent-saving approaches for the extraction of siloxanes from pine needles, soils and passive air samplers

In this study, a solvent-saving analytical strategy was validated to quantify the levels of 8 volatile methyl siloxanes (VMSs) in pine needles, soils and air (measured by sorbent-impregnated polyurethane foam passive samplers, SIPs). Different extraction solvents and sample handling procedures were tested and the protocol that reached the highest recoveries employed QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) and was adapted to pine needles and soils. For SIPs, another method was developed in parallel, as QuEChERS could not be applied to this matrix due to logistic and operative constraints. Thus, extraction was performed using classic Soxhlet extractors and a short clean-up step, limited to the removal of water by a solid-phase extraction (SPE) column containing sodium sulphate. The quantification of the target compounds was performed by gas chromatography/mass spectroscopy (GC/MS), with identical set-ups for the three matrices. Similar validation protocols were applied and yielded limits of detection (LODs) from 1.8 to 10.8 ng kg−1 (dry weight) for pine needles, from 3.4 to 19.8 ng kg−1 (dw) for soils and from 4.7 to 10.2 ngSIP−1 (dw) for SIPs. The overall mean recoveries were 75 ± 11%, 69 ± 17% and 87 ± 8%, respectively. The application of the methodologies to naturally contaminated samples collected in an urban and a remote site revealed siloxane levels comparable to other studies in the literature and a predominance of the cyclic siloxanes over the linear ones, which were frequently not detected.

Development and optimization of a QuEChERS-GC–MS/MS methodology to analyse ultraviolet-filters and synthetic musks in sewage sludge

A Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) methodology followed by gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) analysis was developed to extract synthetic musk compounds (SMCs) (6 polycyclic, 2 macrocyclic and 5 nitro musks) and ultraviolet-filters (UVFs) (6 compounds) from sludge. This methodology fills a gap in the literature, since the proposed technique does not require specific equipment, nor large amounts of solvents, sorbents and time to extract SMCs and UVFs from sludge. To optimize this new methodology, a design of experiments (DoE) approach was used, applying first a screening design (SD) and then a central composite design (CCD). The best conditions achieved to extract these 19 compounds simultaneously were: 500 mg freeze dried sludge, 2.5 min of vortex and 15 min ultrasound and the use of a QuEChERS for the dispersive solid-phase extraction (d-SPE) containing 500 mg MgSO4, 410 mg C18 and 315 mg PSA. Then, this methodology was successfully validated. Recoveries of the target compounds ranged from 75% (cashmeran, DPMI) to 122% (2‑ethylhexyl 4‑methoxycinnamate, EHMC), with good repeatability (relative standard deviation < 10%). The instrumental detection limits (IDLs) and quantification (IQLs) varied from 0.001 pg (musk moskene, MM) to 7.5 pg (musk xylene, MX) and from 0.003 (MM) to 25 pg (MX), respectively. The method detection and quantification limits (MDLs and MQLs) ranged between 0.5 (DPMI) and 1394 (exaltolide, EXA) ng/g dw and 2 and 4648 ng/g-dw, respectively. Both SMCs and UVFs were detected in all sludge samples analysed. Higher concentrations were found for octocrylene (OC: maximum value of 115,486 ng/g-dw) followed by galaxolide (HHCB: 81,771 ng/g-dw). Only the nitro musks ambrette, xylene, moskene and tibetene and macrocyclic musk ethylene brassylate (EB) were not detected in any sample.

Evaluation of dwarf coconut (Cocos nucifera L.) germplasm to the damage intensity caused by foliar diseases

Coconut palm (Cocos nucifera L.) is a perennial crop with economic importance in Brazil. However, the culture is susceptible to several pathogens, such as Camarotella acrocomiae (large verrucosis), C. torrendiella (small verrucosis) and Botryosphaeria cocogena (leaf blight). These diseases reduce the leaf area of the plants. They usually occur as complex which are known as verrucosis leaf blight (CVLB). The objective of this study was to evaluate six accessions of dwarf coconut preserved in the active germplasm bank (AGB) of Embrapa Coastal Tablelands: BYD (Brazilian Yellow Dwarf Gramame), MYD (Malaysian Yellow Dwarf), CRD (Camaroonian Red Dwarf), BRD (Brazilian Red Dwarf Gramame), BGD (Brazilian Green Dwarf Jiqui), and MRD (Malaysian Red Dwarf). The study was carried out in a completely randomized block design with six treatments (accessions) and five replications (blocks), with 11 monthly evaluations from June 2015 to May 2016. The incidence and severity variables for the three diseases were evaluated. These six variables were jointly analyzed to describe the damage intensity. According to the non-metric multidimensional scaling ordination technique, most of the variability of the CVLB (72%) was associated with variations in damage caused by small verrucosis. A smaller portion of the variability (23%) was associated with the damage caused by large verrucosis and leaf blight, which in turn, were modulated by both the accessions and by the environmental variables. Interactions between the accessions and the seasonality of environmental conditions modulate the damage caused to dwarf coconut trees by the foliar diseases complex. These interactions, the duration of the occurrence and the magnitude of the differences between the accessions should be considered by the breeding programs.