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A simple, fast and efficient method was developed for determination of six synthetic dyes (Tartrazine, Sunset Yellow, Amaranth, Ponceau 4R, Indigo Carmine and Brilliant Blue) in sports drinks using dispersive solid-phase extraction (d-SPE) with the polymeric sorbent Oasis ® HLB. Sample preparation using d-SPE permitted to simplify the procedure and use less sorbent in comparison with SPE. The use of a syringe for the elution step make this easier and avoid the use of a manifold. High performance liquid chromatography with UV-Vis detection was employed for quantification. Recovery results, evaluated at 0.5; 1.0 and 1.5 mg L -1 , were between 76 and 108% with relative standard deviation < 18%. The method limit of quantification was 0.5 mg L -1 . The developed method was applied to the analysis of commercial sports drinks and the results indicated that all studied samples presented dye levels in conformity with the Brazilian legislation. Keywords: food additives, beverages, d-SPE, sample preparation, liquid chromatography IntroductionSports drinks are specially formulated for people who are undertaking physical activity, being mainly composed by carbohydrates, electrolytes and vitamins.1 Additives such as flavors, stabilizers and dyes are commonly used in sports drinks to prevent for spoilage and improve their consumer characteristics and appearance. Nevertheless, this addition must not change the properties of the final product.2 Synthetic dyes are a very important class of food additives.3 Besides the lower cost of production in relation to dyes of natural origin, synthetic colorants have several advantages such as high stability to light, oxygen and pH, color uniformity and low microbiological contamination. 4 However, some of these compounds pose adverse health effects (allergy, asthma, hyperactivity, thyroid tumors, etc.), especially when consumed in excess. Thus, their use is strictly controlled around the world. 5 The list of allowable kinds and concentrations of synthetic dyes is different in each country or region, mainly due to differing opinions regarding the safety of these substances and due to a greater or lesser consumption of artificially colored products.6 In Brazil, the maximum limit of colorants in foods including sports drinks is established by the National Agency of Sanitary Surveillance (ANVISA), based on international regulations. 7In general, high-performance liquid chromatography (HPLC) methods with ultraviolet-visible (UV-Vis), diode-array (DAD) and mass spectrometry detection have been employed for synthetic dyes analysis to ensure food safety. Despite the wide variety of cartridges commercially available for preparation/purification of foods matrices, SPE steps can be laborious and often requires vacuum or positive-pressure manifold to perform the extraction. 17,18 Other methods based on the traditional SPE, such as dispersive solid-phase extraction (d-SPE) and magnetic solid-phase extraction (M-SPE), are considered powerful techniques specially for clean-up of food extracts. 8 However, ...

The title compound, [Pb(C4H3N2S)2]n, was prepared by the reaction of [Pb(OAc)2]·3H2O (OAc is acetate) with pyrimidine-2-thione in the presence of triethylamine in methanol. In the crystal structure, the Pb(II) atom has an N4S4 coordination environment with four ligands coordinated by N- and S-donor atoms. This compound shows that the pyrimidine-2-thiolate anion can lead to a three-dimensional network when the coordination number of the metal ion can be higher than 6, as is the case with the Pb(II) ion. This compound presents only covalent bonds, showing that despite the possibility of the hemidirected geometries of Pb(II), the eight-coordinated ion does not allow the formation of an isolated molecular structure with pyrimidine-2-thiolate as the ligand.

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