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Carbamatos são os pesticidas mais frequentemente encontrados em alimentos e bebidas de coloração escura em casos de intoxicação acidental ou intencional. Neste trabalho, extração líquido-líquido com partição em baixa temperatura (LLE-LTP) foi otimizada e validada para determinação dos carbamatos aldicarb, carbofuran e carbaril em bebidas de sucos de uva e leite achocolatado. Este método envolve a extração com acetonitrila, partição líquido-líquido em baixa temperatura e análise por cromatografia líquida de alta eficiência com detecção ultravioleta (HPLC-UV). O método é rápido, eficiente e de baixo custo, emprega pequenos volumes de solvente por amostra e não necessita de limpeza dos extratos. O método de extração foi seletivo e apresentou porcentagens de extração acima de 90%. As premissas relacionadas com os testes estatísticos de linearidade foram verificadas e confirmadas. O método de extração e análise foi validado com resultados satisfatórios e pode ser aplicado em análises de rotina e forenses.Carbamates are the pesticides most commonly found in dark colored foods and beverages in cases of accidental or intentional poisoning. In this work, the liquid-liquid extraction with low temperature partitioning (LLE-LTP) was optimized and validated for determination of the carbamates aldicarb, carbofuran and carbaryl in grape juice and chocolate milk beverages. This method involved extraction with acetonitrile, liquid-liquid partition at low temperature and the analysis by high performance liquid chromatography with ultraviolet detection (HPLC-UV). The method is rapid, efficient and of low-cost, employing small volumes of solvent per sample and requiring no cleanup of the extracts. The extraction methodology was selective and presented recovery percentages above 90%. The premises related to the statistical linearity tests were checked and confirmed. The method of extraction and analysis was validated with satisfactory results, and may be applied in forensic and routine analysis Keywords: carbamates, low temperature partitioning, high performance liquid chromatography, sample preparation, validation IntroductionCarbamate insecticides are widely used in gardening and agriculture due to their broad spectrum of activity and relatively short environmental persistence. However, they are potentially toxic to humans, particularly in the context of intentional self-poisoning. 1,2 Carbamates are found as commercialized products for agricultural practices and some compounds of this group, with their respective commercial names are: carbaryl (Sevin ® ), aldicarb (Temik ® ) and carbofuran (Furadan ® ). From these, aldicarb stands out as the main target on the list of controlled pesticides of the United States Environmental Protection Agency (EPA) due to its elevated toxicity to mammals. 3,4 The maximum residue level (MRL) of aldicarb 5,6 and carbofuran 6 in water is 10 and 7 μg L -1 , respectively. In Goulart et al. 1155 Vol. 23, No. 6, 2012 milk, the MRLs established for aldicarb, 7,8 Exposures may occur accidentally, with ...

An analytical method based on a modified QuPPe (quick polar pesticide) extraction procedure coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was evaluated for the determination of four polar compounds (chlorate, fosetyl-Al, maleic hydrazide, and perchlorate) in nutraceutical products obtained from soy. Experimental conditions including extraction such as solvent, acidification, time, and clean-up sorbents were varied. Acidified acetonitrile (1 % formic acid, v/v) was used as extraction solvent instead of methanol (conventional QuPPe), which provides a doughy mixture which cannot be injected into the LC. Clean-up or derivatization steps were avoided. For analysis, several stationary phases were evaluated and Hypercarb (porous graphitic carbon) provided the best results. The optimized method was validated and recoveries ranged between 46 and 119 %, and correction factors can be used for quantification purposes bearing in mind that inter-day precision was equal to or lower than 17 %. Limits of quantification (LOQs) ranged from 4 to 100 μg kg. Soy-based nutraceutical products were analyzed and chlorate was detected in five samples at concentrations between 63 and 1642 μg kg. Graphical Abstract Analysis of polar compounds in soy-based nutraceutical products.

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