Validação de método multirresíduo para determinação de pesticidas em alimentos empregando QuEChERS E UPLC-MS/MS

This paper presents a practical and rapid method which was validated for simultaneous quantification and confirmation of 29 pesticides in fruits and vegetables using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples were extracted following the method known as QuEChERS. Using the developed chromatographic conditions, the pesticides can be separated in less than 9 min. Two multiple reaction monitoring (MRM) assays were used for each pesticide. Four representative matrices (lettuce, tomato, apple and grapes) were selected to investigate the effect in recoveries and precision. Typical recoveries ranged from 70-120%, with relative standard deviation (RSDs) lower than 20%

Comportamento do herbicida hexazinone em área de recarga do aqüífero Guarani cultivada com cana-de-açúcar

São Paulo state (Brazil) has an important area of sugarcane production, mainly for obtaining alcohol and sugar, where there is an intensive use of pesticides. An important recharge zone of Guarani aquifer, with supplies water for the local population, is located at Ribeirão Preto city, so the local behavior of pesticides must be investigated. The GUS index was obtained by using the paramenters Koc and half-life for hezazinone herbicide, determinated in representative soil of this region. This study has demonstrated that there is potential risks of hexazinone leaching to ground water, indicating that this herbicide must be monitored in ground water

ANÁLISE DE RISCO DE CONTAMINAÇÃO DAS ÁGUAS SUBTERRÂNEAS E SUPERFICIAIS DA REGIÃO DE PETROLINA (PE) E JUAZEIRO (BA)

Analisou-se o potencial de contaminação das águas subterrâneas e superficiais do Submédio do Rio São Francisco por pesticidas aplicados nas culturas de manga e uva, mediante critérios da Environmental Protection Agency, do índice de GUS e critérios propostos por GOSS. Todos os critérios utilizados levam em consideração as propriedades dos produtos aplicados, não demandando custos elevados nem muito tempo para o levantamento das informações e para a avaliação do potencial de contaminação. Os resultados obtidos reforçam a importância de disponibilizar informações sobre as propriedades físico-químicas dos pesticidas, principalmente o coeficiente de adsorção, cujo valor permite a previsão da mobilidade do composto no solo. Este fator, integrado ao conhecimento do tempo de degradação do produto até a metade de sua concentração inicial (meia-vida) no solo, fornece informações sobre a sua influência no potencial de contaminação das águas. Os resultados deste trabalho propiciam o conhecimento dos pesticidas com maior potencial de contaminação dos recursos hídricos, os quais devem ser priorizados no monitoramento ambiental in loco. GROUND AND SURFACE WATER OF THE REGIONS PETROLINA (PE) AND JUAZEIRO (BA) Abstract The contamination potential of ground water and surface water in the sub-middle portion of San Francisco river basin was analyzed for pesticides applied in mango and grape cultivation by following the criteria of Environmental Protection Agency and to the index of GUS and criteria proposed by GOSS. All the criteria used take into consideration the applied products properties, by not demanding high costs nor a long time for rising information and evaluating contamination potential. The results obtained reinforce the importance of information publication on the physicochemical properties of pesticides, especially data on adsorption coefficient, whose values allow to predict the pesticide mobility in soils. This factor combined with the pesticide degradation time to the half of its initial concentration (half life) in the soil, provides information on pesticide water contamination potential. The results of this work allow the identification of the pesticides with higher contamination potential to water resources, which should be prioritized in environmental monitoring in loco

ANÁLISE DE AGROTÓXICOS ORGANOCLORADOS EM CAMARÃO E PESCADO POR CROMATOGRAFIA A GÁS COM DETECTOR DE MICRO CAPTURA DE ELETRONS (GC-µECD)

Otimizou-se um método analítico para a determinação de multirresíduos de organoclorados em camarão marinho para a espécie Litopenaeus vannamei e em músculo de peixes da espécie Oreochromis sp., chamada popularmente de tilápia-vermelha. Utilizou-se a técnica de extração denominada QuEChERS, empregando cromatografia a gás com detector de micro captura de elétrons (CG-µECD) para análise dos seguintes organoclorados em amostras de camarão e em músculo de peixes: hexaclorobenzeno, lindano, DDE, DDT, clorpirifós, endossulfan sulfato, endossulfan beta, endossulfan alfa, heptacloro, aldrin, endrin e dieldrin. O limite de detecção para todos os compostos foi de 0,0005 µg∙g-1 e o limite de quantificação do método foi estabelecido em 0,005 µg∙g-1. Os valores de recuperação variaram entre 80 % e 120 % com desvio padrão (RSD) abaixo de 20 % para todos os compostos

Método para a determinação de hexazinone e tebutiuron em água Method for determination of hexazinone and tebuthiuron in water

<abstract language="eng">This work presents an alternative method for determination of the herbicides tebuthiuron and hexazinone in ground water. The extraction was made with dichloromethane and the analyses by high performance liquid chromatography (HPLC), using reversed-phase column, C-18, mobile phase methanol/water 50:50, v/v, detection and quantification at 247 nm. The following validation parameters were obtained: limit of detection of method 0.02 and 0.03 &micro;g L-1, limit of quantification of method 0.07 and 0.09 &micro;g L-1; linear range limit of quantification of instrument - 300 &micro;g L-1 (r² > 0.998); recoveries from 90.3 to 108.2% and 90.3 to 101.6%; intermediary precision (%RSD) < 8 and < 6%, for hexazinone and tebuthiuron, respectively. The method showed to be efficient and reliable for determination of the herbicides in ground water

Determination of moxidectin in serum by liquid chromatography-tandem mass spectrometry and its application in pharmacokinetic study in lambs

The widespread use of moxidectin (MOX), a parasiticide used in the sheep breeding, has induced the parasite resistance in Brazilian farms. As a consequence, the farmers often increase the dose and frequency of drug utilization, and disregards safety of meat or milk. In order to establish adequate therapeutic treatment it is necessary to know the pharmacokinetics of the drug in the animal's body. Thus, high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) method was developed for the determination of MOX in serum lamb. Serum samples were treated with acetonitrile to precipitate proteins. A clean up by dispersive extraction in solid phase (SPE-d), using primary/secondary amine (PSA) and C18 sorbents, followed by freezing was performed. Method validation presented precision (coefficient of variation) and accuracy (recovery%) between 1.7-6.7 and 80.0-107.3%, respectively. The limit of quantification (LOQ) of the method was 2.0 ng mL-1 and a linear response was obtained over a range of 2.0 to 100 ng mL-1. This method was successfully applied to the determination of MOX in serum from suffolk lamb to evaluate the pharmacokinetic profile282250256CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES305390/2013-9; 483839/2010-8Sem informaçã