**2. Experimental**

carbon-carbon double bonds and carbonyl moieties [2]. The presence of these functional groups affords UV filters the ability to absorb photons and rapidly return to the ground state by thermally emitting the energy through vibrational relaxation [3]. This makes the com-

After application, UV-filters are washed off and enter the aquatic environmental directly or indirectly via wastewater effluent and recreational water systems [4]. They are also used as sun blocking agents in materials such as plastics, adhesive and rubber, this suggests that these compounds can also leach into the environmental matrices [5–7]. The amount and type of UV-filter used depends on the desired degree of protection, however combined concentra-

The main concern of the presence of these compounds is their potential toxicity and their effects as xenohormones (effect on reproductive activity) [9, 10]. These effects include estrogenic activity [11], effects on cell proliferation by 4-methylbenzylidene camphor (4-MBC), benzophenones, and octyl methoxycinnamate (OMC) [12]. Several studies have shown hormonal disruption in both in vivo and in vitro test systems in fish and mammals [13–16]. It has also been recently shown that besides estrogens, there are other hormonal targets affected by

A number of detection techniques have been used to quantify UV-filters in environmental water samples. These include techniques high performance liquid chromatography (HPLC) with UV or mass spectrometry detection [19, 20], HPLC-MS/MS [21], gas chromatography-mass spectrometry (GC-MS) and GC-MS/MS [22, 23]. However, the levels of these compounds in environmental waters are usual in the μg L−1 range. Therefore, sample cleanup/preconcentration techniques such stir-bar sorptive extraction [20], pressurised liquid extraction [1], dispersive liquid-liquid phase extraction [24], solid phase extraction [25], among others, have been used to improve sensitivity, LODs and to remove interferences prior to quantification with the different analytical techniques. Solid phase extraction is one of the most established preconcentration techniques used for the simultaneous extraction and analysis of organic compounds [26]. Mainly silica bonded phases such as C18 were formerly used for SPE, however recently modified and tuned solid phases can be used to achieve more specificity [27]. Advantages of SPE include the potential of simultaneous extraction, reduced labour and cost. Of the advantages of solid phase extraction, scientists are mostly attracted to the possibility of using reduced amount of organic solvents

and the fact that SPE is highly tuneable with regards to the adsorbents used [28].

pound to be able to mitigate the deleterious effects of UV radiation [1, 2].

**Figure 1.** Chemical structures of (a) benzophenone and (b) sulisobenzone.

46 Emerging Pollutants - Some Strategies for the Quality Preservation of Our Environment

tions should not exceed 10% with other organic or inorganic UV-filters [8].

UV-filters in fish and mammals [17, 18].
