Organic ultraviolet (UV) filters are compounds used to absorb UV radiation and are increasingly being used as a result of growing concern about UV radiation and skin cancer. Their growing use may increase environmental contamination and exposure through the food chain. There is therefore major concern about the environmental fate and potential effect of organic UV filters used in beauty creams, hair sprays, shampoos, and other personal-care products, as well as those added to plastics and other materials to prevent degradation of polymers and pigments. This review describes the processes undergone by these compounds once released into the environment and the instrumental methods based on chromatography and mass spectrometry reported in the literature for their determination in environmental samples. We include concentrations found in the environment (e.g., water, soil, sediments, sludge and biota). The main focus is on metabolites, photodegradates and by-products of wastewater treatment.
A new sensitive method has been successfully developed and validated for the simultaneous determination and quantification of nine estrogenic UV filters (benzophenone-1, benzophenone-2, benzophenone-3, benzophenone-4, 4,4-dihydroxybenzophenone, ethyl-4-aminobenzoate, 2-ethyl-hexyl-4-trimethoxycinnamate, 3-(4-methylbenzylidene)-camphor, 3-benzylidene-camphor) in different environmental matrices. After optimisation of extraction conditions for the best recovery of polar to lipophilic compounds from fish tissue and a subsequent lipid clean-up in HPLC, fish extraction recoveries exceeded 72% for all nine UV filters. Identification and quantification of compounds was performed for lipophilic UV filters with gas chromatography–electroionisation-mass spectrometry and for polar and mid-polar compounds with liquid chromatography coupled to electrospray ionisation mass spectrometry. Instrumental detection limits (IDL) varied between 5 and 260 pg injected and method detection limits (MDL) were in the low ng/g lipids range for all test compounds. The described analytical methods are shown to be useful to screen for estrogenic UV filters in environmental samples such as fish and polar organic chemical integrative samplers.
Abstract Sunscreens containing UV filters are recommended to reduce damage caused by solar UV radiation. Recently, benzophenone (BP)-type UV filters have become widely used as UV stabilizers in skin-moisturizing products and sunscreen lotions; however, very little information is available regarding the potential harmful effects of prolonged exposure to these compounds. Therefore, we investigated the toxicokinetics and metabolism of BP-type UV filters in rats using gas chromatography–mass spectrometry (GC–MS). To examine the metabolism of BP-type UV filters, we analyzed the parent compounds BP and 2-hydroxy-4-methoxybenzophenone (HMB). In rats, BP was mainly converted to benzhydrol (BH) and 4-hydroxybenzophenone (HBP) (i.e., type A UV filters). In contrast, HMB was converted into at least three intermediates, including 2,4-dihydroxybenzophenone (DHB), which was formed via o -demethylation and subsequently converted into 2,3,4-trihydroxybenzophenone (THB), and 2,2′-dihydroxy-4-methoxybenzophenone (DHMB), which formed via the aromatic hydroxylation of HMB (i.e., type B UV filters). Next, the toxicokinetic curve for BP showed a peak concentration ( Cmax ) of 2.06 ± 0.46 μg/ml at approximately 4 h after BP administration. After a single oral dose of HMB, the Cmax of HMB reached 21.21 ± 11.61 μg/ml within 3 h ( Tmax ), and then declined rapidly compared to the kinetic curve of BP. The concentration of these metabolites in rat blood decreased much more slowly over time compared to the parent compounds. Thus, our results indicate that such metabolites might have more significant adverse effects than the parent compounds over the long term.
Stir bar sorptive extraction (SBSE) in combination with thermal desorption–gas chromatography–mass spectrometry (TD–GC–MS) was applied for the determination of 9 UV filters in water samples. The stir bar coated with polydimethylsiloxane (PDMS) was added to 20 mL of water sample at pH 2 (10% MeOH) and stirred at 1000 rpm for 180 min. Then, the stir bar was subjected to TD–GC–MS. The desorption conditions (desorption temperature and desorption time) and SBSE parameters (ionic strength, pH, presence of organic solvent and time) were optimised using a full factorial design and a Box-Behnken design, respectively. The method shows good linearity (correlation coefficients >0.994) and reproducibility (RSD < 16%). The extraction efficiencies were above 63% for all the compounds. Detection limits were between 0.2 and 63 ng/L. The developed method offers the ability to detect several UV filters at ultra-low concentration levels with only 20 mL of sample volume. The effectiveness of the method was tested by analysing real samples such as lake water, river water and treated wastewater. The application of the method allowed reporting the levels of UV filters in environmental water samples.
This work studies the stability of three UV filters: 2-ethylhexyl salicylate (ES), 2-ethylhexyl 4-(dimethylamino) benzoate (EHPABA) and 2-hydroxy-4-methoxybenzophenone (BP-3), in water samples containing low concentrations of free chlorine. Moreover, 2,4-dihydroxybenzophenone (2,4-DHBP), a metabolite of BP-3, was also included in some of the performed assays. Experiments were carried out considering free chlorine and analytes concentrations at the μg mL and ng mL level, respectively. Gas chromatography with mass spectrometry was used to follow the time course of target compounds and to identify their halogenated by-products. Concentration of water samples with solid-phase extraction cartridges and derivatization (silylation) of some species were also employed to improve their detectability. Under the experimental conditions explored in this work, ES showed an acceptable stability whereas the rest of species reacted with free chlorine at significant rates following pseudo-first-order kinetics. Their half-lives ranged from 0.4 to 25 min depending on the UV filter, chlorine concentration, water pH and presence of bromide traces. For EHPABA a relatively simple degradation pathway was established. It consisted of aromatic substitution of one atom of hydrogen per chlorine or bromide. The same reaction pattern was observed for BP-3 leading, in this case, to mono- and di-halogenated by-products. In addition, several halogenated forms of 3-methoxyphenol were identified as BP-3 cleavage by-products.
Quantum yields of photodecomposition and triplet state formation under aerobic and anaerobic conditions are determined for kynurenine (KN), 3-hydroxykynurenine (3OHKN), xanthurenic acid (XAN), and kynurenine adducts of glutathione (GSH-KN), cysteine (Cys-KN), histidine (His-KN), and lysine (Lys-KN) in aqueous solutions. The highest yields of anaerobic photodecomposition were obtained for GSH-KN and His-KN adducts, which correlates with the highest triplet yields for these compounds. In aerobic conditions, the photodecomposition yields for all compounds under study increase; the highest decomposition rates were observed for His-KN and 3OHKN. The fast decomposition of the latter is attributed to the dark autoxidation of the starting compound.
Previous studies in extracts of sediments surrounding municipal outfalls off the coast of California, USA and effluents of New York City, NY, USA indicated the UV-filtering agent, oxybenzone (CAS# 131-57-7; benzophenone-3) as a potential estrogen. The effects of oxybenzone on estrogenic activity and reproduction were evaluated using a 14-day juvenile rainbow trout assay for plasma vitellogenin and a subsequent 21-day Japanese medaka reproduction assay. Significant induction of vitellogenin was observed in the rainbow trout at the 1000 μg/L nominal concentration (749 μg/L median measured value) of oxybenzone which was approximately 75 times greater than the concentrations observed in previous wastewater effluent. Vitellogenin induction was also observed in the 1000 μg/L nominal concentration (620 μg/L median measured) of oxybenzone in male Japanese medaka ( ) after 21 days of exposure. The number of eggs produced per female per day exposed to the same concentration (620 μg/L) were significantly lower after 7 days, but returned to control values after 21 days. Fertilized eggs were then monitored for 20 days to assess hatching success. The overall percentage of fertilized eggs collected during the 21-day exposure that hatched was significantly lower in the 620 μg/L oxybenzone concentration. There was also a temporal effect at this concentration as egg viability (percentage of fertilized eggs that hatched) was diminished 13–15 days after eggs were collected. All three oxybenzone concentrations (16, 132, and 620 μg/L) and the 50 ng/L estradiol positive control showed reduced hatching of eggs at day 15, and the 132 and 620 μg/L oxybenzone concentrations diminished the percentage of eggs that hatched on days 13–15. These data indicate that the UV-filter oxybenzone alters endocrine or reproduction endpoints in two fish species, but at concentrations significantly higher than those measured in the environment.
A useful tool for the determination of eight UV filters in sediments which combines extraction and clean-up in a single-step has been developed. To this end, the protocol incorporates silica gel and copper powder placed directly in the pressurised-liquid extraction (PLE) cell. After extract evaporation, salicylate- and benzophenone-type UV filters are derivatised with , -bis-trimethylsilyltrifluoroacetamide (BSTFA). Trimethylsilylation increases the sensitivity of these UV filters about 4–10-fold when they are finally analysed by gas chromatography–mass spectrometry (GC–MS). Derivatisation conditions (temperature, time and volume of BSTFA) and PLE parameters (temperature, time, number of cycles and solvent composition) were optimised using multivariate experimental designs. Under optimal conditions, the developed procedure provides an excellent linearity, detection limits (1–5 ng g ) and recoveries above 73% for all the compounds. Compared to the few existing methods, this analytical approach affords optimal throughput and method automation. Finally, the proposed method was applied to the analysis of three sediment samples.
Analysis of UV filter levels in 48 cataractous human lenses was performed with the use of HPLC. A new chromophore with the absorption maximum at 410 nm and molecular mass of 369 Da was detected and assigned as deaminated 3-hydroxykynurenine β- -glucoside (3OHCKAG). Cataractous lenses are characterized by the wide range of the UV filter concentrations and remarkably lower levels of UV filters and glutathione than published for the normal lenses. No correlation between the lens age and the level of UV filters has been found in cataractous lenses.