Journal of Chromatography A, 1216 (2009) 5895–5902 Contents lists available at ScienceDirect Journal of Chromatography A journal homepage: www.elsevier.com/locate/chroma Determination of selected UV filters in indoor dust by matrix solid-phase dispersion and gas chromatography–tandem mass spectrometry N. Negreira, I. Rodríguez ∗ , E. Rubí, R. Cela Departamento de Química Analítica, Nutrición y Bromatología, Instituto de Investigación y Análisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782, Spain article info Article history: Received 27 March 2009 Received in revised form 26 May 2009 Accepted 5 June 2009 Available online 10 June 2009 Keywords: UV filters Dust Indoor atmospheres Matrix solid-phase dispersion Gas chromatography–tandem mass spectrometry abstract A simple, inexpensive sample preparation procedure, based on the matrix solid-phase disper- sion (MSPD) technique, for the determination of six UV filters: 2-ethylhexyl salicylate (EHS), 3,3,5-trimethylcyclohexyl salicylate (Homosalate, HMS), 3-(4-methylbenzylidene) camphor (4-MBC), isoamyl-p-methoxycinnamate (IAMC), 2-ethylhexyl-p-methoxycinnamate (EHMC) and octocrylene (OCR), in dust from indoor environments is presented and the influence of several operational parameters on the extraction performance discussed. Under the final working conditions, sieved samples (0.5 g) were mixed with the same amount of anhydrous sodium sulphate and dispersed with 2 g of octadecyl bonded silica (C18) in a mortar with a pestle. This blend was transferred to a polypropylene solid-phase extraction cartridge containing 2 g of activated silica, as the clean-up co-sorbent. The cartridge was first rinsed with 5 mL of n-hexane and the analytes were then recovered with 4 mL of acetonitrile. This extract was adjusted to 1mL, filtered and the compounds were determined by gas chromatography combined with tandem mass spectrometry (GC–MS/MS). Recoveries for samples spiked at two different concentrations ranged between 77% and 99%, and the limits of quantification (LOQs) of the method between 10 and 40 ng g -1 . Analysis of settled dust from different indoor areas, including private flats, public buildings and vehicle cabins, showed that EHMC and OCR were ubiquitous in this matrix, with maximum concentrations of 15 and 41 gg -1 , respectively. Both UV filters were also quantified in dust reference material SRM 2585 for first time. EHS, 4-MBC and IAMC were detected in some of the analyzed samples, although at lower concentrations than EHMC and OCR. © 2009 Elsevier B.V. All rights reserved. 1. Introduction UV filters are compounds designed to mitigate the deleterious effects of sunlight. Most of them are organic substances, character- ized by single or multiple aromatic structures, often with attached hydrophobic groups [1]. One of their most common uses is in sun- screens, which are preparations that are applied directly on the skin to protect against UV radiation. Many countries have legis- lated both maximum allowable concentrations of UV filters and the combination of individual organic compounds that can be included in these products. For example, in the European Union, 26 organic compounds have been approved to be incorporated in sunscreens at individual concentrations up to 10%, for most of them [2,3]. Moreover, they are also included in the formulation of other personal care products (cosmetics, hair dyes and sham- poos) and used in the protection of goods, plastics, varnishes and clothes [4–7]; however, no data could be traced related to the type ∗ Corresponding author. Tel.: +34 981 563100x14387; fax: +34 981 595012. E-mail address: isaac.rodriguez@usc.es (I. Rodríguez). of UV absorbers and the concentrations incorporated in these mate- rials. As many other daily usage compounds, UV filters are continu- ously discharged into the aquatic environment. Washing off from the skin, during bathing and swimming, and indirect releases from towels and clothes contribute significantly to their presence in surface and wastewater samples [8]. The behaviour of these com- pounds in the aquatic environment depends on a number of factors such as (1) their stability during wastewater treatments [4,9,10], (2) their physicochemical properties, particularly their water solubil- ity, and (3) their potential transformation through photochemical and/or oxidation reactions [11,12]. Medium and highly polar UV filters, such as 2-hydroxy-4-methoxybenzophenone (BP-3) and 2- hydroxy-4-methoxybenzophenone-5-sulphonic acid (BP-4) have been often detected in surface and wastewater [6,7,13]; moreover, BP-4 is not effectively removed by conventional sewage treatments [6]. More lipophilic species, such as 3-(4-methylbenzylidene) camphor (4-MBC), 2-ethylhexyl-p-methoxycinnamate (EHMC) and octocrylene (OCR) have been found in river and lake sediments [14], sludge [15] and even in biota [4,16]. In fact, concentrations of up to 2 gg -1 have been reported for 4-MBC and OCR in fish [16] and as 0021-9673/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.chroma.2009.06.020