Evaluation of the QuEChERS Method and Gas Chromatography–Mass Spectrometry for the Analysis Pesticide Residues in Water and Sediment

A method for the determination of pesticide residues in water and sediment was developed using the QuEChERS method followed by gas chromatography – mass spectrometry. The method was validated in terms of accuracy, specificity, linearity, detection and quantification limits. The recovery percentages obtained for the pesticides in water at different concentrations ranged from 63 to 116%, with relative standard deviations below 12%. The corresponding results from the sediment ranged from 48 to 115% with relative standard deviations below 16%. The limits of detection for the pesticides in water and sediment were below 0.003 mg L−1 and 0.02 mg kg−1, respectively

Considerations on the Aquaculture Development and on the Use of Veterinary Drugs: Special Issue for Fluoroquinolones-A Review

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Aquaculture has become an important source of fish available for human consumption. In order to achieve greater productivity, intensive fish cultivation systems are employed, which can cause greater susceptibility to diseases caused by viruses, bacteria, fungi, and parasites. Antimicrobial substances are compounds used in livestock production with the objectives of inhibiting the growth of microorganisms and treatment or prevention of diseases. It is well recognized that the issues of antimicrobial use in food animals are of global concern about its impact on food safety. This paper present an overview of the aquaculture production in the whole world, raising the particularities in Brazil, highlighting the importance of the use of veterinary drugs in this system of animal food production, and address the potential risks arising from their indiscriminate use and their impacts on aquaculture production as they affect human health and the environment. The manuscript also discusses the analytical methods commonly used in the determination of veterinary drug residues in fish, with special issue for fluroquinolones residues and with emphasis on employment of LC-MS/MS analytical technique.789R1321R1333Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Determination of quinolone residues in tilapias (Orechromis niloticus) by HPLC-FLD and LC-MS/MS QToF

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)A method for the simultaneous determination of flumequine, oxolinic acid, sarafloxacin, danofloxacin, enrofloxacin, and ciprofloxacin in tilapia (Orechromis niloticus) fillet, using high-performance liquid chromatography with fluorescence detection (HPLC-FLD) is presented. The quinolones were extracted from the food matrix with a solution of 10% trichloroacetic acid and methanol (80:20 v/v). Clean-up of the extract was performed using polymeric solid-phase extraction cartridges. Identification of the quinolones was confirmed by liquid chromatography-tandem mass spectrometry. The HPLC-FLD method was validated in-house and the following analytical parameters were obtained: linearity higher than 0.99 for all the quinolones; intra- and inter-assay precisions were lower than 3.5% and 10.9%, respectively; and recoveries ranged from 73% to 110%. The limit of quantification was below the maximum residue limit established by the Joint Expert Committee on Food Additives (JECFA), which indicates that the method is appropriate for the determination of quinolones in fish fillet.261013311340Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Streptomycin and dihydrostreptomycin residues in bovine milk from the Brazilian retail market

Pasteurised bovine milk from retail markets in the State of Sao Paulo, Brazil, was analysed for the presence of streptomycin (STP) and dihydrostreptomycin (DHSTP) residues. An ELISA kit was used for screening and a LC-APCI-MS/ MS QToF method for confirmatory analysis. Both methods were intra-laboratory validated and found suitable for screening and confirmatory testing, respectively, for STP and DHSTP residues in pasteurised bovine milk at concentration levels below the maximum residue limit (MRL) established for these substances (200 mu g kg(-1) expressed as the sum of the concentrations of STP and DHSTP). No residues of STP and DHSTP at detectable levels were found in the analysed samples (n 299).3315616

Depletion study and estimation of the withdrawal period for enrofloxacin in pacu (Piaractus mesopotamicus)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Defining the pharmacokinetic parameters and depletion intervals for antimicrobials used in fish will help in the development of important guidelines for future regulations by Brazilian agencies on the use of these substances in fish farming. This paper presents a depletion study for enrofloxacin (ENR) and its main metabolite, ciprofloxacin (CIP), in pacu (Piaractus mesopotamicus) fillets. The depletion study was carried out under monitored environmental conditions, with the temperature controlled at 27 degrees C to mimic the fish farming conditions in Brazil. ENR was administered orally via medicated feed for 10 consecutive days at daily dosages of 10mg/kg body weight (b.w.). The fish were slaughtered at 6, 12, and 24h and 2, 3, 5, 8, 12, 17, and 24days after the medication period. Considering a maximum residue limit of 100g/kg for the sum of the ENR and CIP residues in the fillet, the results obtained in the depletion study allowed the estimation of a half-life for ENR of 2.75days and a withdrawal period of 23days. The results obtained in this study are important for the farming of pacu in tropical regions.366594602Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Electrochemical behavior of dopamine at a 3,3 '-dithiodipropionic acid self-assembled monolayers

Monolayers of 3,3'-dithiodipropionic acid (DTDPA) were prepared on a polycrystalline gold electrode through a self-assembly procedure to produce a gold 3,3'-dithiodipropionic acid self-assembled monolayer (AuDTDPA) modified electrode. The characterization of the AuDTDPA electrode was investigated by cyclic voltammetry and ac impedance using the [Fe(CN)(6)](3-/4-) redox couple. The electrochemical behavior of DA on the modified electrode AuDTDPA was studied by cyclic and square-wave voltammetries, using phosphate buffer as supporting electrolyte. The oxidation peak current for DA increases linearly with concentration in the range of 0.35 x 10(-5) to 3.4 x 10(-5) mol L-1. The performance of the AuDTDPA modified electrode was evaluated for the electroanalytical determination of dopamine (DA) in a pharmaceutical formulation. The AuDTDPA modified electrode showed a stable behavior and the presence of surface-COOH groups avoided the passivation of the electrode surface during the dopamine oxidation. (c) 2006 Elsevier B.V. All rights reserved.72242743

Antioxidant activity of aqueous extract of passion fruit (Passiflora edulis) leaves: In vitro and in vivo study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Passion fruit (Passiflora edulis), including its leaves, is a rich source of bioactive compounds, as polyphenols. This study investigated the in vitro and in vivo antioxidant potential of aqueous extract of P. edulis leaves and identification of phenolic compounds by HPLC-PDA and ESI-MS/MS analysis. Male Wistar rats were divided in two groups (n = 6 per group). Control group received water and experimental group received P. edulis leaf extract (Tea) (1.1 mg dry leaves mL(-1)), both ad libitum. Total phenols and antioxidant potential (DPPH, FRAP, ABTS and ORAC assay) were determined in aqueous extract. Antioxidant status was analyzed by FRAP, ORAC in serum and by SOD, GR and GPx activities, GSH contents and TBARS in liver, brain and kidneys. Gut microbiota profile and short-chain fatty acids were determined in feces. Vitexin, isovitexin and isoorientin were analyzed in the extract of P. edulis leaves. The animals which received tea showed a decrease of 20% of TBARS in liver. GSH contents in kidneys increased 40% relative to control group. The GR activity was 2 times higher and GPx 3.2 times lower in liver than control group. Animals from TEA group showed a 45% reduction on SOD activities in liver and brain. Serum antioxidant potential was not altered. Tea intake also promoted colonic bacteria growth, although there was a decreasing in the SCFA production. Therefore, P. edulis leaf extract could be an option to enhance the supply of antioxidants and to safeguard against oxidative stress. (C) 2013 Elsevier Ltd. All rights reserved.532SI882890Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Sepsis expands a CD39+ plasmablast population that promotes immunosuppression via adenosine-mediated inhibition of macrophage antimicrobial activity

Sepsis results in elevated adenosine in circulation. Extracellular adenosine triggers immunosuppressive signaling via the A2a receptor (A2aR). Sepsis survivors develop persistent immunosuppression with increased risk of recurrent infections. We utilized the cecal ligation and puncture (CLP) model of sepsis and subsequent infection to assess the role of adenosine in post-sepsis immune suppression. A2aR-deficient mice showed improved resistance to post-sepsis infections. Sepsis expanded a subset of CD39hi B cells and elevated extracellular adenosine, which was absent in mice lacking CD39-expressing B cells. Sepsis-surviving B cell-deficient mice were more resistant to secondary infections. Mechanistically, metabolic reprogramming of septic B cells increased production of ATP, which was converted into adenosine by CD39 on plasmablasts. Adenosine signaling via A2aR impaired macrophage bactericidal activity and enhanced interleukin-10 production. Septic individuals exhibited expanded CD39hi plasmablasts and adenosine accumulation. Our study reveals CD39hi plasmablasts and adenosine as important drivers of sepsis-induced immunosuppression with relevance in human disease