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1.
Scientifica (Cairo) ; 2024: 1960065, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38356694

RESUMO

Moxidectin (MOX) is used to control helminth parasites in ruminant livestock. It is released through feces and remains in the environment for a long period. This study aimed to evaluate the impact of faeces excreted by moxidectin-treated sheep on soil biodiversity (coprophagous insects, soil microbial biomass, and activity) to establish environment-related guidelines regarding the use of MOX in sheep livestock. The study consisted of two experiments. In the first one, faeces from MOX-treated (subcutaneous dose of 0.2 mg·kg-1 body weight) and nontreated rams were placed on an animal-free pasture field, protected or not against rain, for 88 days. Then, coprophagous insects were captured, identified, and counted, and faeces degradation was evaluated by measuring dry weight and carbon (C) and nitrogen (N) contents over time. Diptera, Hymenoptera, Isoptera, and Coleoptera were equally encountered in faeces from MOX-treated and nontreated animals. Faecal boluses of MOX-treated animals (with higher N content) not protected against rain degraded faster than faecal boluses of nontreated animals (with lower N content). In the second experiment, faeces from nontreated animals were amended with increasing amounts of MOX (75 to 3,000 ng·kg-1 faeces), mixed with soil samples from animal-free pasture (1.9 to 75 ng·kg-1 soil), and incubated in a greenhouse for 28 days. Increasing concentrations of MOX did not prevent the growth of cultivable bacteria, actinobacteria, or fungi in culture media. However, even the lower MOX concentration (1.9 ng·kg-1 soil) abruptly decreased soil microbial biomass, basal respiration, and N mineralization. Thus, the results indicate that faeces excreted from sheep treated with MOX under the experimental conditions of this study are not harmful to the coprophagous insects. However, adding MOX to faeces from drug-free sheep had a negative impact on soil microbial activity and biomass.

2.
Curr Res Physiol ; 5: 256-264, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35800140

RESUMO

The interest in nutritional strategies that may counteract the deleterious oxidative effects induced by strenuous exercises is remarkable. Herein, the impact of white tea (Camellia sinensis) (WT), a polyphenol-rich beverage, on antioxidant status in endurance-trained rats after one session of exhaustive exercise were evaluated. Male Wistar rats were divided into groups, which received: control groups - water, and testing groups - WT1 (0.25%; w/v) or WT2 (0.5%; w/v). Drinks were consumed, ad libitum, for 5 or 10 weeks, concomitantly with the running training. Exhaustive running tests were applied before and after the experimental periods. WT intake increased the serum antioxidant capacity of rats in a dose-dependent manner (P < 0.001), which was unaccompanied by the activity of endogenous antioxidant enzymes SOD, GPx, and GR, and GSH content. Inflammatory markers in serum [IL-1ß (P = 0.004) and IL-6 (P = 0.001)] could be downregulated by tea intake. In liver tissue, lower levels of lipid oxidation (P < 0.05) and improved antioxidant defenses (SOD, GPx, GR, and GSH, P < 0.05) were related to the consumption of WT in both doses, supporting protective effects in this responsible metabolic organ. In conclusion, long-term consumption of WT could be a promising adjuvant to exercise-stress management, emphasizing its ability to regulate antioxidant responses and prevent oxidative tissue damage.

3.
Food Chem ; 366: 130587, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34332424

RESUMO

Miniaturized and simplified sample preparation methods with reduced consumption of chemicals and non-halogenated solvents are presented for the determination of 12 sulfonamides in baby foods. Hydrophilic interaction liquid chromatography coupled to quadrupole time-of-flight mass spectrometry was used for the identification and quantification of the compounds based on the acquisition of full spectrum at high resolution with accurate mass for precursor and its fragment ions. Three miniaturized protocols based on QuEChERS, salting-out assisted liquid-liquid extraction or low-temperature cleanup were evaluated regarding the extraction efficiency and removal capability of matrix co-extractives. All approaches achieved satisfactory recoveries (70.0-120.0%); however, the miniaturized QuEChERS distinguished by lower co-extractives content in the final extract providing lower matrix effects. Thus, the performance characteristics of the miniaturized QuEChERS were established using different matrices: beef-, egg yolk- and vegetable-based baby food or chicken- and vegetable-based baby food, in compliance with the Codex Alimentarius Commission guidelines. The target compounds were investigated in 30 commercial baby foods.


Assuntos
Antibacterianos , Alimentos Infantis , Animais , Bovinos , Cromatografia Líquida , Alimentos Infantis/análise , Espectrometria de Massas , Carne/análise , Sulfonamidas
4.
Artigo em Inglês | MEDLINE | ID: mdl-34477497

RESUMO

This study provides the first data related to albendazole (ABZ) and its main metabolites [albendazole sulphoxide (ABZSO), albendazole sulphone (ABZSO2), and albendazole-2-amino sulphone (ABZ-2-NH2-SO2)] residue depletion in tambaqui (Colossoma macropomum) parasitised by acanthocephalan (Neoechinorhynchus buttnerae). The ABZ withdrawal period was also calculated. The fish received a daily dose of 10 mg ABZ kg-1 body weight (b.w.) via medicated feed for 34 days. Samples of target tissue (muscle plus skin in natural proportions) were collected 24, 48, 72, 120, 168, 240, and 336 h after the end of ABZ administration. The quantitation of ABZ residues and its metabolites in the target tissue was performed using a validated ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analytical method. After treatment, ABZ in the target tissue was rapidly metabolised over time, and ABZSO was the most persistent metabolite and was shown to be at the highest levels in the target tissue. Considering the maximum residue limit (MRL) established by Codex Alimentarius in the muscle (100 µg kg-1, species not specified), a withdrawal period of 4 days (112 °C-day) was estimated for the total residue (sum of ABZ and its metabolite residues). Considering data reported in the literature and data obtained in this study, it is suggested that the total residue be considered as marker residue to be adopted for fish in the legislative framework.


Assuntos
Acantocéfalos , Albendazol/farmacocinética , Albendazol/uso terapêutico , Caraciformes , Doenças dos Peixes/tratamento farmacológico , Helmintíase Animal/tratamento farmacológico , Administração Oral , Albendazol/metabolismo , Ração Animal , Animais , Anti-Helmínticos/farmacocinética , Anti-Helmínticos/uso terapêutico , Resíduos de Drogas , Helmintíase Animal/parasitologia , Reprodutibilidade dos Testes
5.
Artigo em Inglês | MEDLINE | ID: mdl-34237233

RESUMO

The influence of fish burger preparation and frying on residual levels of enrofloxacin (ENR) and ciprofloxacin (CIP) was evaluated. For this purpose, a high-throughput liquid chromatography-mass spectrometry analytical method for the quantitation of ENR and CIP residues in tilapia products (fillet, raw fish burger and fried fish burger) was developed and validated based on European and Brazilian guidelines. Sample preparation was accomplished by extraction with acidified acetonitrile followed by clean-up with hexane. Chromatographic analysis was performed on a C18 column using isocratic elution with 0.1% formic acid and acetonitrile (85:15 v:v). The analytical method showed suitable performance to quantify the residual levels of ENR and CIP in the studied matrices. No reduction in the residual levels of ENR and CIP was observed during fish burger preparation and only a 10% reduction occurred as a consequence of frying, indicating that both compounds were stable to the preparation of the fish burger and to frying conditions.


Assuntos
Ciclídeos , Ciprofloxacina/química , Resíduos de Drogas/química , Enrofloxacina/química , Produtos Pesqueiros/análise , Manipulação de Alimentos , Animais , Antibacterianos/química
6.
Food Res Int ; 140: 109865, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33648183

RESUMO

This study was carried out to assess the occurrence of antimicrobial residues in samples of tilapia (Oreochromis niloticus) fillets collected at the State of São Paulo retail market and produced from fish farmed in Brazil. For this purpose, a liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method was validated and used to quantify residues of 25 antibacterial drugs (2 ß-lactams, 8 quinolones, 2 macrolides, 5 sulfonamides, 4 tetracyclines, 3 amphenicols and 1 sulfonamide potentiator). For the sample preparation step the QuEChERS approach was performed. Chromatographic separation was conducted using a Zorbax SB C18 column. Method validation was performed based on European and Brazilian guidelines. The validation parameters (linearity, intra- and inter-day precision, accuracy, decision limit, detection capability and robustness) attended the adopted validation guidelines. Limits of detection and quantitation were also determined. Antimicrobial drug residues were quantitated in the incurred samples by using matrix-matched analytical curves. Oxytetracycline, florfenicol and, for the first time, enrofloxacin residues are reported in tilapia fillet samples from Brazil, though, in accordance with the European and Brazilian regulatory framework. Thus, our results draw attention to the use of veterinary products in fish farming in Brazil. Monitoring of veterinary drug residues is essential to ensure the safety of fish products available to the consumer, as well as to keep fish as a food commodity.


Assuntos
Anti-Infecciosos , Ciclídeos , Tilápia , Animais , Antibacterianos , Brasil , Cromatografia Líquida , Espectrometria de Massas em Tandem
7.
Acta amaz ; 51(1): 71-78, jan.-mar. 2021.
Artigo em Inglês | LILACS | ID: biblio-1353162

RESUMO

Uma possível alternativa ao uso de fármacos veterinários no tratamento e prevenção de doenças na piscicultura é o uso do óleo essencial de Piper aduncum. No entanto, são necessários dados ecotoxicológicos para garantir seu uso apropriado sem causar efeitos adversos a organismos não alvo. Esta informação é relevante, pois esse óleo essencial é descrito como tendo atividades inseticidas, moluscicidas e citotóxicas, possivelmente associadas à sua composição química. Assim, o objetivo deste estudo foi avaliar a ecotoxicidade do óleo essencial de P. aduncum para cinco organismos-teste, usando o método estatístico da Distribuição da Sensibilidade das Espécies (SSD). A composição química do óleo essencial foi caracterizada por cromatografia gasosa acoplada a espectrometria de massa (GC-MS) e cromatografia gasosa com detector de ionização de chama (GC-FID), para fins de identificação e quantificação, respectivamente. O principal componente (75,5%) do óleo essencial foi o dilapiol. A concentração perigosa para 5% de espécies biológicas (HC5) foi calculada com um nível de proteção de 95%, resultando em um valor de 0,47 mg L-1 (com intervalo de confiança de 50% = 0,028 - 1,19 mg L-1). A faixa de concentração relacionada aos níveis de proteção para comunidades aquáticas (concentração sem efeito previsto - PNEC) foi calculada através da aplicação de fatores de segurança ao valor de HC5. Os parâmetros de ecotoxicidade indicaram que o óleo essencial de P. aduncum pode ser usado com segurança em corpos d'água se a concentração for igual ou inferior a 0,09 mg L-1.(AU)


Assuntos
Atenção , Cleome
8.
Food Addit Contam Part B Surveill ; 14(1): 40-47, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33327891

RESUMO

Glyphosate (GLY) is the most widely used herbicide in the world and studies have shown that its exposure at sublethal doses has led to reduced sensitivity and decreased associative memory in bees. Thus, a high-performance liquid chromatography-fluorescence detector with derivatisation reaction was used to determine residues of GLY and aminomethylphosphonic acid (AMPA) in Brazilian honey. The method met the validation criteria of the European Union (EU) SANTE 11813/2017 guideline and showed a limit of quantitation of 0.04 µg g-1 for both GLY and AMPA. Residues of these compounds were quantitated in honey samples from five Brazilian States. Six samples showed GLY levels above the EU maximum residue limit (0.05 µg g-1) and one sample showed AMPA at 0.10 µg g-1. This study indicates the presence of GLY residues in honey from regions that have had high losses of bee colonies and at the same time, frequent use of GLY in agriculture.


Assuntos
Herbicidas , Mel , Resíduos de Praguicidas , Animais , Abelhas , Contaminação de Alimentos/análise , Glicina/análogos & derivados , Glicina/análise , Glicina/toxicidade , Herbicidas/análise , Mel/análise , Organofosfonatos , Resíduos de Praguicidas/análise , Glifosato
9.
J Chromatogr A ; 1633: 461606, 2020 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-33128969

RESUMO

An accurate, sensitive and selective analytical method is proposed for sulfonamide residues analysis in infant formulas based on hydrophilic interaction liquid chromatography (HILIC) and quadrupole time-of-flight mass spectrometry in full scan mode. The sample preparation approach involves low-temperature lipid precipitation followed by dispersive solid-phase extraction with PSA and C18 sorbents, which was successfully optimized using Plackett-Burman design. In order to achieve high analytical sensitivity, the influence of HILIC conditions on sulfonamide ionization was investigated, such as the mobile phase composition, buffer concentration, and sample diluent for injection. The method performance characteristics, including linearity (range 5-120 µg kg-1), reliable limits of quantification (between 5 and 20 µg kg-1), recovery (72.9-109.2%) and precision (coefficient of variation values ≤ 19.8%) under repeatability and within-laboratory reproducibility conditions, were in accordance with the Codex Alimentarius Commission CAC/GL 71-2009 for quantitative analytical methods for veterinary drug residues in foods. Moreover, adequate identification of the compounds was provided with accurate mass measurement of both precursor and fragment ions in one single run. Finally, the developed method was applied to thirty-five powdered milk-based infant formula samples available in the Brazilian market.


Assuntos
Cromatografia Líquida , Resíduos de Drogas/análise , Análise de Alimentos/métodos , Fórmulas Infantis/química , Espectrometria de Massas , Sulfonamidas/análise , Brasil , Contaminação de Alimentos/análise , Humanos , Interações Hidrofóbicas e Hidrofílicas , Lactente , Reprodutibilidade dos Testes , Extração em Fase Sólida
10.
Artigo em Inglês | MEDLINE | ID: mdl-31176266

RESUMO

The development and validation of a throughput method for the determination of 25 antibacterial drugs (two ß-lactams, eight quinolones, two macrolides, five sulfonamides, trimethoprim, four tetracyclines and three amphenicols) in pangasius fish muscle by LC-MS/MS were performed. A simple, efficient and fast extraction procedure was developed using acetonitrile and a 0.1 M EDTA solution as solvents for extraction. All compounds were determined in a single run, and chromatographic separation was achieved using a Zorbax SB C18 column with a mobile phase comprised of purified water +0.1% formic acid (A) and acetonitrile +0.1% formic acid (B) in a linear gradient program. The method was validated aαording to the requirements of European Decision 2002/657/EC. To quantify the analytes, matrix-matched analytical curves were constructed with spiked blank tissues and showed linearity (r2) higher than 0.99. For all analytes, the precision and accuracy were determined at the levels of 3 ng/g (low), 10 ng/g (low-middle), 50 ng/g (high-middle) and 100 ng/g (high). The precision (CV%) was lower than 18.6% and the accuracy (determined as recovery) was between 65% and 119%. The limit of quantitation was 3.0 ng/g, with the exception of chloramphenicol, which was 0.3 ng/g, and amoxicillin and doxycycline, which were 10 ng/g. The method was successfully applied to analyze pangasius muscle samples from Vietnam available at the Brazilian retail market, and 5 out of 40 samples showed the presence of low-residue levels of enrofloxacin and, consequently, must be considered out of conformity. It is recommended that competent authorities should avoid the commercialization of pangasius fillet contaminated with residues of this veterinary drug.


Assuntos
Antibacterianos/análise , Cromatografia Líquida de Alta Pressão/métodos , Resíduos de Drogas/análise , Produtos Pesqueiros/análise , Espectrometria de Massas em Tandem/métodos , Animais , Peixes-Gato , Cloranfenicol/análise , Contaminação de Alimentos/análise , Tetraciclinas/análise , Trimetoprima/análise , Vietnã
11.
Res Vet Sci ; 114: 406-411, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28750211

RESUMO

The indiscriminate and continuous use of anthelmintic drugs has promoted the selection of resistant parasites population, the presence of drug residues in food products, and heavy environmental contamination. The aim of the present study was to determine the presence of antiparasitic drug residues in 42-days old lamb serum and tissues, submitted to three endoparasite control programs: preventive treatment (PT) using moxidectin (MOX) at every 28days; selective treatment (FEC) using MOX when fecal egg count was greater than or equal to 700; and selective treatment (FMC), using MOX when FAMACHA/FMC score was 3 and above. For this purpose, MOX residues were quantified in serum, muscle, fat, liver and kidney. Lambs were slaughtered when reaching 30kg of body weight, and after a 28-day MOX withdrawal period. Before slaughter, blood was collected to determine the concentration of MOX in serum. Tissues and organ samples were collected at slaughter. The quantitation of MOX residues was performed using liquid chromatography tandem mass spectrometry (LC-MS/MS). From the 756 tissue samples analyzed, only one sample of fat from the PT group showed residue levels (586.3µg/kg) above the maximum residue limit (MRL) of 500µg/kg. No treated lambs presented traces of MOX residues in fat and liver, suggesting possible environmental contamination. In conclusion, all weaned lambs, produced in continuous grazing and subjected to gastrointestinal parasite control programs via selective (FEC and FMC) or preventive (PT) treatment, displayed a low risk (<1%) of MOX residues above the MRL in muscle, fat, kidney, and liver.


Assuntos
Anti-Helmínticos/análise , Resíduos de Drogas/análise , Macrolídeos/análise , Doenças Parasitárias em Animais/tratamento farmacológico , Doenças dos Ovinos/tratamento farmacológico , Animais , Anti-Helmínticos/uso terapêutico , Brasil , Feminino , Macrolídeos/uso terapêutico , Masculino , Doenças Parasitárias em Animais/parasitologia , Distribuição Aleatória , Ovinos , Doenças dos Ovinos/parasitologia , Fatores de Tempo , Distribuição Tecidual
12.
J Agric Food Chem ; 65(4): 800-809, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-28064494

RESUMO

The impact of the naturally present phenolic compounds and/or proteins on the antioxidant capacity of flaxseed products (phenolic fraction, protein concentrates, and hydrolysates) before and after simulated gastrointestinal digestion was studied. For that, whole and phenolic reduced products were assessed. Four glycosylated phenolic compounds (secoisolariciresinol and ferulic, p-coumaric, and caffeic acids) were identified in flaxseed products. Phenolic fraction exerts the highest antioxidant capacity that increased by alkaline hydrolysis and by simulated gastrointestinal digestion. The action of Alcalase and digestive enzymes resulted in an increase of the antioxidant capacity of whole and phenolic reduced products. Principal component analysis showed that proteinaceous samples act as antioxidant is by H+ transfer, while those samples containing phenolic compounds exert their effects by both electron donation and H+ transfer mechanisms. Protein/peptide-phenolic complexation, confirmed by fluorescence spectra, exerted a positive effect on the antioxidant capacity, mainly in protein concentrates.


Assuntos
Antioxidantes/química , Linho/química , Fenóis/química , Extratos Vegetais/química , Proteínas de Plantas/química , Sementes/química , Antioxidantes/metabolismo , Linho/metabolismo , Trato Gastrointestinal/metabolismo , Humanos , Hidrólise , Espectrometria de Massas , Modelos Biológicos , Fenóis/metabolismo , Extratos Vegetais/metabolismo , Proteínas de Plantas/metabolismo , Sementes/metabolismo
13.
Bull Environ Contam Toxicol ; 97(4): 528-35, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27225508

RESUMO

Sulfamethazine (SMZ) is one of the most commonly used sulfonamide compounds in fish farming, and its physiological effects on fish are unknown. SMZ was administered to juvenile Nile tilapia (Oreochromis niloticus) at a dose level of 422 mg kg(-1) body weight, for a period of 11 days, via medicated feed. Fish were divided into two groups, the control group (CG) and the group fed with SMZ in feed. The administration of SMZ did not alter the erythrograms and leukograms of the Nile tilapia. The SMZ-fed group showed the same hepatic lipid peroxidation (LPO) concentration as the CG. Nonetheless, the oral administration of SMZ raised the hepatic catalase (CAT) and glutathione S-transferase (GST) activities, the increase probably being sufficient to prevent hepatic LPO production. The oral administration of SMZ affects the hepatic GST and CAT activities of Nile tilapia.


Assuntos
Ciclídeos/metabolismo , Dieta , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/enzimologia , Estresse Oxidativo/efeitos dos fármacos , Sulfametazina/toxicidade , Administração Oral , Animais , Anti-Infecciosos/toxicidade , Biomarcadores/metabolismo , Contagem de Células Sanguíneas , Catalase/metabolismo , Glutationa Transferase/metabolismo , Fígado/metabolismo , Sulfametazina/administração & dosagem
14.
Talanta ; 152: 498-503, 2016 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-26992547

RESUMO

The use of electric fields as additional driving forces in sample preparation techniques is an innovative approach that is environmentally friendly, straightforward, and able to overcome several limitations of conventional sample preparation procedures. In this work, the advantages of electric field-assisted solid phase extraction (E-SPE) using syringe-type cartridges were demonstrated for the extraction of four fluoroquinolones (FQs) in their anionic forms. The FQs were extracted from eggs and subsequently determined by UHPLC-MS/MS. The use of electric fields during the washing and final elution steps resulted in a significant improvement of the extraction efficiencies for almost all FQs when compared to conventional SPE. Intra- and inter-day assays showed coefficients of variation below 10%. The better cleanup also resulted in the appearance of less precipitated matter in the final eluate, as well as reduced matrix effects. The results showed that the electrophoretic forces derived from electric fields are a promising way of significantly increasing the extraction efficiency of ionic analytes, while minimizing matrix effects associated with complex samples.


Assuntos
Ovos/análise , Eletricidade , Fluoroquinolonas/isolamento & purificação , Extração em Fase Sólida/métodos , Cromatografia Líquida de Alta Pressão , Fluoroquinolonas/análise , Espectrometria de Massas em Tandem
15.
J Sep Sci ; 38(21): 3781-7, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26332708

RESUMO

Focusing on the demand from the food industry for fast and reliable alternative methods to control the quality of food products, we present in this paper a method for amino acid separation and glutamic acid quantification in complex matrices employing capillary electrophoresis with capacitively coupled contactless conductivity detection. We demonstrate by simulation and experimentally the use of organic solvents in sample preparation to prevent peak splitting and increase stacking in capillary electrophoretic separations of amino acids. Additionally, we obtained results for glutamic acid quantification comparable to those obtained via traditional methods used at industrial sites. We tested premium and low-cost samples with large variations in their glutamic acid content, which demonstrated the wide range of applicability of the method presented herein. The results of the proposed capacitively coupled contactless conductivity detection based capillary electrophoresis method agreed with those obtained by an enzymatic detector and ultra high performance liquid chromatography coupled to tandem mass spectrometry, considering a confidence level of 95%.


Assuntos
Eletroforese Capilar/métodos , Ácido Glutâmico/análise , Solventes/química , Artefatos , Alimentos de Soja/análise
16.
J Food Sci ; 78(9): R1321-33, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23909512

RESUMO

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.


Assuntos
Anti-Infecciosos/farmacologia , Aquicultura/métodos , Fluoroquinolonas/farmacologia , Inocuidade dos Alimentos , Drogas Veterinárias/farmacologia , Animais , Brasil , Cromatografia Líquida , Resíduos de Drogas/análise , Peixes , Espectrometria de Massas em Tandem
17.
Artigo em Inglês | MEDLINE | ID: mdl-23731191

RESUMO

The use of antimicrobials in livestock production is a powerful resource applied throughout the world to guarantee high yield and control bacterial diseases in aquaculture. However, residues of these substances in animal products represent a potential risk to consumer health when residue levels are above the established maximum residue limits (MRLs). Fluoroquinolones (FQs) are antimicrobials commonly used worldwide in aquaculture. The aim of this work was to develop and validate a simple analytical method for the simultaneous determination of norfloxacin, danofloxacin, enrofloxacin and ciprofloxacin levels in tilapia (Oreochromis niloticus) and pacu (Piaractus mesopotamicus) fillets using liquid chromatography-tandem mass spectrometry (LC-MS/MS) quadrupole time of flight (QToF). The FQs were extracted from the fillets with 1% acetic acid-methanol and 1% acetic acid-acetonitrile solutions using ultrasonic assistance. The clean-up was performed with hexane. Chromatographic separation was conducted in an XTerra RP18 column (2.1 × 150 mm, 5 µm) at 25 °C with a flow of 0.2 mL min⁻¹. The mobile phase consisted of 0.1% aqueous formic acid and acetonitrile, with gradient elution. The validation parameters for all FQs were linearity (>0.99), intra-day precision (CV of 1%-9%), inter-day precision (CV of 3%-17%), decision limit (63-126 ng g⁻¹), detection capability (76 -152 ng g⁻¹) and accuracy (90%-111%). The limit of quantification was lower than the MRL for each FQ, indicating that the method is suitable for the determination of the FQ levels in the fish fillets. The mass analyser of the QToF type was able to confirm the identities of the FQs with an error of the accuracy of the mass (reasons m/z) of less than 10 ppm.


Assuntos
Antibacterianos/análise , Characidae , Cromatografia Líquida/métodos , Resíduos de Drogas/análise , Fluoroquinolonas/análise , Espectrometria de Massas em Tandem/métodos , Tilápia , Animais , Padrões de Referência
18.
Springerplus ; 1(1): 37, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23396675

RESUMO

Azo dyes constitute the largest and most versatile class of synthetic dyes used in the textile, pharmaceutical, food and cosmetics industries and represent major components in wastewater from these industrial dying processes. Biological decolorization of azo dyes occurs efficiently under low oxygen to anaerobic conditions. However, this process results in the formation of toxic and carcinogenic amines that are resistant to further detoxification under low oxygen conditions. Moreover, the ability to detoxify these amines under aerobic conditions is not a wide spread metabolic activity. In this study we describe the use of Brevibacterium sp. strain VN-15, isolated from an activated sludge process of a textile company, for the sequential decolorization and detoxification of the azo dyes Reactive Yellow 107 (RY107), Reactive Black 5 (RB5), Reactive Red 198 (RR198) and Direct Blue 71 (DB71). Tyrosinase activity was observed during the biotreatment process suggesting the role of this enzyme in the decolorization and degradation process, but no-activity was observed for laccase and peroxidase. Toxicity, measured using Daphnia magna, was completely eliminated.

19.
J Chromatogr A ; 1218(10): 1319-30, 2011 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-21292271

RESUMO

A method for the determination of volatile organic compounds (VOCs) in recycled polyethylene terephthalate and high-density polyethylene using headspace sampling by solid-phase microextraction and gas chromatography coupled to mass spectrometry detection is presented. This method was used to evaluate the efficiency of cleaning processes for VOC removal from recycled PET. In addition, the method was also employed to evaluate the level of VOC contamination in multilayer packaging material containing recycled HDPE material. The optimisation of the extraction procedure for volatile compounds was performed and the best extraction conditions were found using a 75 µm carboxen-polydimethylsiloxane (CAR-PDMS) fibre for 20 min at 60 °C. The validation parameters for the established method were linear range, linearity, sensitivity, precision (repeatability), accuracy (recovery) and detection and quantification limits. The results indicated that the method could easily be used in quality control for the production of recycled PET and HDPE.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Polietilenotereftalatos/química , Polietileno/química , Microextração em Fase Sólida/métodos , Compostos Orgânicos Voláteis/análise , Embalagem de Alimentos , Modelos Lineares , Reciclagem , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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