Multiclass Pesticide Analysis In Fruit-based Baby Food: A Comparative Study Of Sample Preparation Techniques Previous To Gas Chromatography-mass Spectrometry

With the aim to develop a new gas chromatography-mass spectrometry method to analyze 24 pesticide residues in baby foods at the level imposed by established regulation two simple, rapid and environmental-friendly sample preparation techniques based on QuEChERS (quick, easy, cheap, effective, robust and safe) were compared - QuEChERS with dispersive liquid-liquid microextraction (DLLME) and QuEChERS with dispersive solid-phase extraction (d-SPE). Both sample preparation techniques achieved suitable performance criteria, including selectivity, linearity, acceptable recovery (70-120%) and precision (<= 20%). A higher enrichment factor was observed for DLLME and consequently better limits of detection and quantification were obtained. Nevertheless, d-SPE provided a more effective removal of matrix co-extractives from extracts than DLLME, which contributed to lower matrix effects. Twenty-two commercial fruit-based baby food samples were analyzed by the developed method, being procymidone detected in one sample at a level above the legal limit established by EU. (C) 2016 Elsevier Ltd. All rights reserved.212528536Santander International Mobility Program (VRERI) [020/2014]REQUIMTE FCT (Fundacao para a Ciencia e a Tecnologia)FEDER from FCT/MEC by FEDER [UID/QUI/50006/2013, POCI/01/0145/FEDER/007265

Optimisation of a sample preparation method for the determination of fumonisin B-1 in rice

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)A simple, rapid and cost-effective sample preparation method for the determination of fumonisin B-1 in rice was optimised using a strategy of sequential experimental designs. Initially, a Plackett-Burman design was applied to select the statistically significant variables for the determination of fumonisin B-1, and then, a central composite rotatable design was used to define the optimal conditions of these variables. The method involves extraction with a 50% acetonitrile aqueous solution and glacial acetic acid, liquid-liquid partitioning with addition of anhydrous sodium sulphate and sodium chloride, followed by dispersive SPE clean-up with diatomaceous earth. The final extract was analysed by HPLC-FLD after precolumn derivatisation with ortho-phthaldialdehyde. The optimised method was validated for selectivity, linearity, matrix effect, limits of detection and quantification, trueness, and precision, and then applied to commercial samples of polished rice. This is the first report of the occurrence of fumonisin B-1 in commercial samples of polished rice from the Southeast region of Brazil. (C) 2014 Elsevier Ltd. All rights reserved.158270277Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq