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1.
Ecotoxicol Environ Saf ; 208: 111638, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396158

RESUMO

The flame retardant decabrominated diphenyl ether (BDE-209) is a widely used chemical in a variety of products and exists extensively in the environment. BDE-209 has been reported to induce kidney injury and dysfunction. However, the causes and mechanisms of its nephrotoxicity are still under investigation. In this study, 150 male broilers were exposed to BDE-209 concentrations of 0, 0.004, 0.04, 0.4, 4.0 g/kg for 42 days. The relative kidney weight, histopathology, markers of renal injury, oxidative stress, inflammation, apoptosis and the expression of MAPK signaling pathways-related proteins were assessed. The results showed that the concentrations of blood urea nitrogen (BUN), creatinine (CRE) and the neutrophil gelatinase-associated lipocalin (NGAL), significantly increased after exposure to BDE-209 with the doses more than 0.04 g/kg. Similarly, severe damage of renal morphology was observed, including atrophy and necrosis of glomeruli, and swelling and granular degeneration of the renal tubular epithelium. In the renal homogenates, the oxidative stress was evidenced by the elevated concentrations of MDA and NO, and decreased levels of GSH-Px, GSH and SOD. Due to the inflammatory response, the level of NF-κB and the pro-inflammatory cytokines TNF-α, IL-1ß, IL-18 were remarkably upregulated, while the content of the anti-inflammatory cytokine IL-10 decreased. Additionally, the apoptotic analysis showed notable upregulations of Bax/Bcl-2 ratio, the relative expression of p-ERK1/2 and p-JNK1/2, and the expression of Bax, cytochrome c and caspase 3. The present study indicates that BDE-209 exposure can cause nephrotoxicity in broilers through oxidative stress and inflammation, which activate the phosphorylation of key proteins of the MAPK signaling pathways, and subsequently induce mitochondria-mediated kidney apoptosis.


Assuntos
Lesão Renal Aguda/induzido quimicamente , Poluentes Ambientais/toxicidade , Retardadores de Chama/toxicidade , Éteres Difenil Halogenados/toxicidade , Lesão Renal Aguda/metabolismo , Lesão Renal Aguda/patologia , Animais , Apoptose/efeitos dos fármacos , Galinhas , Inflamação/induzido quimicamente , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Estresse Oxidativo/efeitos dos fármacos
2.
Environ Pollut ; : 115121, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33139099

RESUMO

Polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), as the secondary environmental pollutants of the widely used brominated flame retardants (BFRs), possess the similar physicochemical and toxic properties as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). However, studies on human body exposure to them are extremely limited. In this study, forty human milk samples collected in Shanghai were measured for 13 PBDD/F congeners using gas chromatography-high resolution mass spectrometry (GC-HRMS), to investigate their exposure level and characteristics, potential source and corresponding health risks to breastfed infants. The results showed no PBDDs but three PBDF congeners including 2,3,7,8-TBDF, 1,2,3,4,6,7,8-HpBDF and OBDF (mean concentration (detection rates) are 3.2 pg/g (72.5%), 9.5 pg/g (100%) and 28 pg/g (67.5%), respectively) were detected. The average toxic equivalent quantity (TEQ, 0.42 pg/g lw) presented the highest concentration level compared to other regions reported. The contribution of PBDFs to the total TEQ of PBDD/Fs and PCDD/Fs is 6.8%. The correlation between PBDD/Fs and age or dietary habits was not observed, which normally existed in their chlorinated analogues-PCDD/Fs. Significant correlations were observed between PBDFs and highly brominated polybrominated diphenyl ethers (PBDEs) (especially for BDE 183 and BDE 209). The correlation between PCDD/Fs and PBDFs was not observed except 2,3,7,8-TBDF. The high PBDFs exposure in Shanghai may originate from the emission of PBDEs and/or non-PBDE BFRs in environment, according to the consistency of the environmental data previously reported. The average estimated dietary intakes (EDI) for breastfed infants is 2.0 pg TEQ/kg·bw/day (0.13-13 pg TEQ/kg·bw/day), within the range of the tolerable daily intake (TDI) for TCDD (1-4 pg TEQ/kg·bw/day) suggested by the World Health Organization (WHO). However, given the high toxicity of PBDD/Fs, the potential health risks of these pollutants for breastfed infants should be of concern.

3.
Food Chem ; : 128379, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33097333

RESUMO

Shanghai city has encountered possible food fraud regarding the geographical mislabeling of vegetables for economic gain. A combination of δ13C, δ15N, δ2H and δ18O values and partial least squares discrimination analysis and support vector machine (SVM) methods were used for the first time to assess farming methods and determine the origin of vegetables from Shanghai city, Anhui and Zhejiang provinces. The results showed that 65.8% of Shanghai vegetables, 38.2% of Anhui vegetables and 23.6% of Zhejiang vegetables appeared to be grown using green or organic farming methods. The optimal discriminant model was obtained using SVM with a predictive accuracy of 100% for Shanghai vegetables. Zhejiang vegetables had a predictive accuracy of 91.7%, while it was difficult to distinguish Anhui vegetables from Shanghai or Zhejiang vegetables. Therefore, this study provided a useful method to identify vegetable farming methods and discriminate vegetables from Shanghai and Zhejiang.

4.
Food Chem Toxicol ; 145: 111632, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32738377

RESUMO

Neonicotinoid insecticides have been widely used in plant protection against pests worldwide. Generally, more than one neonicotinoids are detected in plants and foods, and such mixtures may show combined toxicity and increase the risk for both insects and higher organisms. In this study, the combined toxicity of imidacloprid (IM), acetamiprid (AC) and thiamethoxam (TH) was investigated using human neuroblastoma cell line (SK-N-SH) and lepidopteran cell line (Sf-9). Results showed that binary and ternary mixtures could enhance the inhibition of growth of both SK-N-SH and Sf-9 cells at low doses. In SK-N-SH cells, based on CompuSyn software analysis, all the mixtures of IM+AC, IM+TH, AC+TH and IM+AC+TH showed synergistic effects at concentrations < 50 mg/L, but IM+AC, IM+TH showed antagonistic effects at higher concentrations. For Sf-9 cells, all mixtures revealed synergistic effects at low concentrations (< 0.1 mg/L) except IM+AC, showing antagonism at higher concentrations (> 0.5 mg/L). The toxicity thresholds of mixtures denoted by BMDL10 values were all lower than those for single pesticides and the combined BMDL10 value of AC+TH was the lowest one. It is concluded that the co-occurrence of several neonicotinoid insecticides may enhance their toxicity and aggravate the health risk for both insects and human.

5.
Chemosphere ; 254: 126837, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32339803

RESUMO

An improved understanding of imidacloprid (IMI) metabolism and accumulation in casing soil or compost-mushroom systems will help to optimise the safe use of IMI for agricultural pest control in Agaricus bisporus cultivation. In this study, the dissipation, metabolites and accumulation of IMI in casing soil or compost-A. bisporus systems were investigated. The results show that the IMI dissipation half-lives at doses of 10 and 50 mg kg-1 were 65 d and 59 d in casing soil and 6.6 d and 6.2 d in compost, respectively during the cultivation period. Three IMI metabolites were observed in casing soil during cultivation of mushrooms. Urea-imidacloprid (IMI-urea) was a major metabolite, accounting for more than 59%. In compost, the main metabolite in the first 5 days was IMI-urea, from 5 to 10 days olefin-imidacloprid (IMI-ole) and 6-chloronicotinic acid (6-CNA) were both the most prominent compounds, and after 10 days 6-CNA alone. At 50 mg kg-1 dose, IMI and the metabolites (IMI-urea, IMI-ole) were detected in the fruiting body with IMI applied to casing soil and only the metabolite 6-CNA was detected in fruiting body with IMI applied to compost. The bio concentration factors (BCFs) of IMI-ole and IMI-urea were higher than of IMI and 6-CNA, and the BCFs had no obvious relationship with log Kow. Furthermore, the potential dietary risk of IMI in A. bisporus was acceptable when application rates in casing soil or compost was up to 50 mg kg-1. Our study supports a safe use of IMI as agricultural pest control in A. bisporus cultivation.


Assuntos
Agaricus/metabolismo , Inseticidas/metabolismo , Neonicotinoides/metabolismo , Nitrocompostos/metabolismo , Agricultura , Compostagem , Dieta , Exposição Dietética/estatística & dados numéricos , Frutas , Medição de Risco , Solo
6.
Artigo em Inglês | MEDLINE | ID: mdl-30954688

RESUMO

Chinese mitten crab, a featured macrobenthos, has been one of the most important economical aquatic species in China. This study assessed the accumulation of an organochlorine pesticide methoxychlor (MXC) in Chinese mitten crab during exposure to 1 mg/L of MXC. The results showed the residual concentration of MXC in the ovary and hepatopancreas reached 55.07 ±â€¯2.64 ng/g and 34.51 ±â€¯2.35 ng/g, respectively. After exposure, tubular vacuolization of epithelial tissues, condensed egg cells and obvious intervals between egg cell wall and stroma were observed in the hepatopancreas and ovary, respectively. Significant changes of three key metabolic enzymes in hepatopancreas were observed upon exposure to MXC. Compared to the control, acetylcholinesterase level was significantly higher at day 7 (0.15 ±â€¯0.01 vs. 0.06 ±â€¯0.00 U/mgprot); glutathione S-transferase level was elevated at both day 4 (12.01 ±â€¯0.48 vs. 3.20 ±â€¯0.44 U/mgprot) and day 7 (12.84 ±â€¯1.01 vs. 8.22 ±â€¯0.81 U/mgprot); superoxide dismutase was sharply increased at day 4 (21.20 ±â€¯0.24 vs. 3.66 ±â€¯0.60 U/mgprot) but decreased at day 7 (3.74 ±â€¯0.12 vs. 9.44 ±â€¯0.85 U/mgprot). Overall, dissolved MXC accumulated in lipid-rich tissues could cause damages on epithelial cells and egg cells and change metabolic activities of enzymes involved in antioxidative stress and detoxification processes.


Assuntos
Braquiúros/metabolismo , Metoxicloro/metabolismo , Metoxicloro/toxicidade , Animais , Feminino , Hepatopâncreas/efeitos dos fármacos , Hepatopâncreas/metabolismo , Ovário/efeitos dos fármacos , Ovário/metabolismo , Distribuição Tecidual , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/toxicidade
7.
Ecotoxicol Environ Saf ; 170: 306-313, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30530183

RESUMO

Novel brominated flame retardants (NBFRs), which are lipophilic compounds that have been widely applied after the phasing-out of legacy BFRs, can bioaccumulate through the food chain. However, information on NBFRs in animal feeds, the beginning of farm-to-fork pathway, is very limited. Fishmeal is one of the most widely applied feedstuff worldwide. The present study identified eleven NBFRs from ninety-two globally collected fishmeal samples with levels in the range of 0.13-822 (mean: 15.1 ±â€¯85.5) ng/g lipid weight (lw). Hexabromobenzene (HBB) and pentabromotoluene (PBT) were the most prevalent contributors (detection frequencies: 95.7% and 73.9%, respectively), and decabromodiphenylethane (DBDPE) was the weightiest contributor (accounted for 67.1% of the ΣNBFRs, mean: 12.1 ±â€¯84.8 ng/g lw). From a geographical view, the highest NBFR level was found in Chinese fishmeal. The NBFRs fell within an order of magnitude in South America, Southeast Asia, Europe and United States. DBDPE was predominant in the fishmeal collected from China, South America and United States, but it was not detected in European fishmeal. The NBFR levels are significantly lower compared to the polybrominated diphenyl ethers (PBDEs) (p < 0.01), indicating that the distribution of NBFRs was not as wide as PBDEs in fishmeal. DBDPE was significantly correlated with BDE209 (r = 0.557, p < 0.01), which implies that the two chemicals might have similar sources. Quantitative structure-activity relationship (QSAR)results imply that the NBFRs might have similar persistence and biomagnification potential as legacy lipophilic POPs.


Assuntos
Ração Animal/análise , Bromobenzenos/análise , Monitoramento Ambiental/métodos , Retardadores de Chama/análise , Contaminação de Alimentos/análise , Tolueno/análogos & derivados , Animais , China , Europa (Continente) , Cadeia Alimentar , Relação Quantitativa Estrutura-Atividade , América do Sul , Tolueno/análise
8.
Artigo em Inglês | MEDLINE | ID: mdl-27131104

RESUMO

The analysis of veterinary drugs in organic fertilizers is crucial for an assessment of potential risks to soil microbial communities and human health. We develop a robust and sensitive method to quantitatively determine 19 veterinary drugs (amantadine, sulfonamides and fluoroquinolones) in organic fertilizers. The method involved a simple solid-liquid extraction step using the combination of acetonitrile and McIlvaine buffer as extraction solvent, followed by cleanup with a solid-phase extraction cartridge containing polymeric mixed-mode anion-exchange sorbents. Ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was used to separate and detect target analytes. We particularly focused on the optimization of sample clean-up step: different diluents and dilution factors were tested. The developed method was validated in terms of linearity, recovery, precision, sensitivity and specificity. The recoveries of all the drugs ranged from 70.9% to 112.7% at three concentration levels, with the intra-day and inter-day relative standard deviation lower than 15.7%. The limits of quantification were between 1.0 and 10.0µg/kg for all the drugs. Matrix effect was minimized by matrix-matched calibration curves. The analytical method was successfully applied for the survey of veterinary drugs contamination in 20 compost samples. The results indicated that fluoroquinolones had higher incidence rate and mean concentration levels ranging from 31.9 to 308.7µg/kg compared with other drugs. We expect the method will provide the basis for risk assessment of veterinary drugs in organic fertilizers.


Assuntos
Cromatografia por Troca Iônica/métodos , Resíduos de Drogas/análise , Fertilizantes/análise , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Drogas Veterinárias/análise , Resíduos de Drogas/química , Resíduos de Drogas/isolamento & purificação , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes , Drogas Veterinárias/química , Drogas Veterinárias/isolamento & purificação
9.
J Sep Sci ; 38(13): 2245-52, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25907799

RESUMO

A sensitive, simple and reliable analytical method based on a modified quick, easy, cheap, effective, rugged, safe sample preparation and liquid chromatography with tandem mass spectrometry detection was developed for the simultaneous determination of amicarbazone and its two major metabolites desamino amicarbazone and isopropyl-2-hydroxy-desamino amicarbazone residues in grains (rice, wheat, corn, buckwheat) and soybean. Several parameters, including liquid chromatography and tandem mass spectrometry conditions, extraction approaches and the adsorbents for clean-up, which might influence the accuracy of the method, were extensively investigated. The established method was further validated by determining the linearity (R(2) > 0.99), fortified recovery (79-118%), precision (1-12%) and sensitivity (limit of quantification, 5 µg/kg for amicarbazone and desamino amicarbazone, and 10 µg/kg for isopropyl-2-hydroxy-desamino amicarbazone). Finally, the established method was successfully applied to determine the residues of amicarbazone and its metabolites in 49 real samples of grain and soybean.

10.
Artigo em Inglês | MEDLINE | ID: mdl-24935763

RESUMO

A simple and reliable method for simultaneous determination of deoxynivalenol-3-glucoside and major type B trichothecenes (deoxynivalenol, nivalenol, fusarenon X, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol and deepoxy-deoxynivalenol) in animal feed and raw materials has been developed and validated in this study. The method was based on an improved dispersive solid-phase extraction (DSPE) followed by analysis using high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). Also, matrix-matched calibration curve (R(2)>0.99) was employed to minimize matrix effects and ensure accurate quantification. The recoveries during sample preparation process (including extraction and clean-up) ranged from 79.03% to 118.39%, with intra-day and inter-day relative standard deviation lower than 20% for all the analytes. The limit of quantification ranged from 5.0 µg/kg for deoxynivalenol to 13.6 µg/kg for fusarenon X. The validated method was successfully applied to the analysis of animal feed and corn. The pilot study showed that 37 out of 41 samples were contaminated with deoxynivalenol-3-glucoside at the levels of 6.0-121.0 µg/kg. Most of the type B trichothecenes were also found with the exception of fusarenon X, at the contaminated levels of 10.0-1,382 µg/kg. To the best of our knowledge, this was the first scientific report on the co-occurrence of masked deoxynivalenol and type B trichothecenes in animal feed and raw materials.


Assuntos
Ração Animal/análise , Cromatografia Líquida/métodos , Glucosídeos/análise , Extração em Fase Sólida/métodos , Tricotecenos/análise , Ração Animal/microbiologia , Animais , Limite de Detecção , Espectrometria de Massas em Tandem/métodos , Zea mays/química , Zea mays/microbiologia
11.
Anal Chim Acta ; 720: 126-33, 2012 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-22365130

RESUMO

In this study we propose a chromogenic platform for rapid analysis of organophosphate (OP) and carbamate (CM) insecticide residues, based on recombinant Drosophila melanogaster acetylcholinesterase (R-DmAChE) as enzyme and indoxyl acetate as substrate. The visible chromogenic strip had the advantages identical to those of commonly used lateral flow assays (LFAs) with utmost simplicity in sample loading and result observation. After optimization, depending on the color intensity (CI) values, the well-established assay has the capabilities of both qualitative measurement via naked eyes and quantitative analysis by colorimetric reader with the desirable IC(50) values against the tested six insecticides (0.06 µg mL(-1) of carbofuran, 0.28 µg mL(-1) of methomyl, 0.03 µg mL(-1) of dichlorvos, 31.6 µg mL(-1) of methamidophos, 2.0 µg mL(-1) of monocrotophos, 6.3 µg mL(-1) of omethoate). Acceptable matrix effects and satisfactory detection performance were confirmed by in-parallel LC-MS/MS analysis in different vegetable varieties at various spiked levels of 10(-3) to 10(1) µg g(-1). Overall, the testified suitability and applicability of this novel platform meet the requirements for practical use in food safety management and environmental monitoring, especially in the developing world.


Assuntos
Acetilcolinesterase/metabolismo , Carbamatos/análise , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/enzimologia , Inseticidas/análise , Compostos Organofosforados/análise , Acetilcolinesterase/genética , Animais , Colorimetria , Proteínas de Drosophila/genética , Indóis/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Especificidade por Substrato , Verduras/química
12.
Artigo em Inglês | MEDLINE | ID: mdl-22197443

RESUMO

A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for simultaneous determination of five acid/alkaline phytohormones, i.e., indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), naphthylacetic acid (NAA), gibberellic acid (GA(3)) and isopentenyladenine (2IP), in grapes was developed. After optimization, the samples were extracted with methanol containing 1% formic acid and purified by Oasis HLB SPE cartridges. The analytes were separated on a Thermo Hypersil Gold column (100 mm×2.1 mm, 3.0 µm) with water and acetonitrile, then determined with Thermo tandem quadrupole mass spectrometer operating in negative electro-spray ionization using selected reaction monitoring (SRM) mode. The established method was further validated by determining the linearity (R² ≥ 0.9990), average recovery (82.5-105.4%), sensitivity (0.05-1.00 ng mL⁻¹), precision (RSD ≤1 3.0%) and stability (RSD ≥ 82.0%). Finally, the application of the approach proposed to thirty grape samples convinced its desirable performance for rapid analysis of multiclass phytohormones, supporting its sufficient capability for multiresidue analyses or other analytical system targeting phytohormones in agriculture field.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Reguladores de Crescimento de Planta/análise , Espectrometria de Massas em Tandem/métodos , Vitis/química , Resíduos de Drogas/análise , Resíduos de Drogas/isolamento & purificação , Estabilidade de Medicamentos , Giberelinas/análise , Giberelinas/isolamento & purificação , Ácidos Indolacéticos/análise , Ácidos Indolacéticos/isolamento & purificação , Indóis/análise , Indóis/isolamento & purificação , Isopenteniladenosina/análise , Isopenteniladenosina/isolamento & purificação , Naftóis/análise , Naftóis/isolamento & purificação , Extratos Vegetais/química , Reguladores de Crescimento de Planta/isolamento & purificação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Extração em Fase Sólida/instrumentação , Extração em Fase Sólida/métodos
13.
Foodborne Pathog Dis ; 8(10): 1055-62, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21612425

RESUMO

In this study, 20 samples from three different sources of animal feed were investigated and six bacterial isolates were identified. The susceptibility of four natural antimicrobials, namely, eugenol, cinnamaldehyde, thymol, and carvacrol, against six of these isolates was determined. Carvacrol and eugenol showed better inhibitory effects with larger zones of inhibition. The minimal inhibitory concentration for a range of antibiotics on the susceptibility of two isolates (namely, Sphingomonas paucimobilis and Klebsiella oxytoca) was investigated using the VITEK® 2 microbiological identification system. Both isolates showed a variety of resistance to 18 antibiotics. The minimal inhibitory concentration and fractional inhibitory concentration index of those two isolates for ampicillin and nitrofurantoin in combination with four phenolic compounds was determined. Synergistic interactions were found for most antimicrobial/antibiotic combinations; thymol and carvacrol were very effective (fractional inhibitory concentration ≤0.5) in combination with all antibiotics tested against S. paucimobilis and K. oxytoca, respectively. Ultra performance liquid chromatography techniques were used to investigate the physiological effects of the four natural antimicrobials against those two isolates. Two identical peaks were found to be systematically different between cinnamaldehyde-treated and -untreated cells. The identity of the peaks is unknown and further investigation is needed.


Assuntos
Ração Animal/microbiologia , Anti-Infecciosos/farmacologia , Farmacorresistência Bacteriana , Klebsiella oxytoca/efeitos dos fármacos , Extratos Vegetais/farmacologia , Sphingomonas/efeitos dos fármacos , Acroleína/análogos & derivados , Acroleína/farmacologia , Ampicilina/farmacologia , Animais , Bovinos , Cimenos , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Patos , Eugenol/farmacologia , Microbiologia de Alimentos , Klebsiella oxytoca/fisiologia , Testes de Sensibilidade Microbiana , Monoterpenos/farmacologia , Nitrofurantoína/farmacologia , Percepção de Quorum/efeitos dos fármacos , Sphingomonas/fisiologia , Suínos , Timol/farmacologia
14.
J Sep Sci ; 32(23-24): 4254-60, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19937858

RESUMO

This work demonstrates the potential of HPCE in the analysis of antibiotics in a complex matrix such as feedstuffs. Using 20 mM citric acid-40 mM Na(2)HPO(4) buffer (pH 2.65), the five antibiotics, tetracycline, oxytetracycline, doxycycline, tilmicosin, and tylosin were successfully separated at 30 kV in a 64.5 cm x 75 microm id capillary. Good repeatability, stability, and reliability of the method were supported by <10% CV with mean recoveries of >70%, and the limit of detection of the five analytes was 0.5-1 mg/kg. It was for the first time that a capillary electrophoretic method was employed to simultaneously detect five tetracycline and macrolide antibiotics in animal feeds.


Assuntos
Ração Animal/análise , Antibacterianos/análise , Eletroforese Capilar/métodos , Animais , Antibacterianos/normas , Bovinos , Eletroforese Capilar/normas , Macrolídeos/análise , Padrões de Referência , Tetraciclinas/análise
15.
J Food Prot ; 72(10): 2189-94, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19833044

RESUMO

A sensitive and reliable method was developed for the detection of doramectin (DRM) in rabbit tissues (muscle, liver, kidney, and fat) by high-performance liquid chromatography with fluorescence detection. The limit of detection and the limit of quantification were 0.36 ng.g(-1) and 1 ng.g(-1), respectively, for all four tissues examined. Mean recoveries ranged from 70.8 to 98.0% for all samples at all fortification levels with a coefficient of variation below 12.1%. The method was further applied to study depletion of DRM residues in rabbits subcutaneously administered a single dose of 0.4 mg.kg(-1) body weight. The highest DRM concentration was measured in fat tissue, indicating that fat is the target tissue for DRM in rabbits. Although the concentrations of DRM residues in all tissues were below the maximum residue limits established by the European Medicines Agency, the Codex Alimentarius Commission, and the Ministry of Agriculture of China for other food-producing species at 16 days posttreatment, the statistically established withdrawal period was calculated to be 23 days.


Assuntos
Tecido Adiposo/química , Anti-Helmínticos/farmacocinética , Resíduos de Drogas/análise , Ivermectina/análogos & derivados , Coelhos/metabolismo , Animais , Anti-Helmínticos/administração & dosagem , Disponibilidade Biológica , Cromatografia Líquida de Alta Pressão/métodos , Fluorescência , Injeções Subcutâneas , Ivermectina/administração & dosagem , Ivermectina/farmacocinética , Rim/química , Fígado/química , Músculos/química , Fatores de Tempo , Distribuição Tecidual
16.
J AOAC Int ; 92(4): 1009-15, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19714965

RESUMO

A high-performance capillary electrophoretic method for determination of five benzimidazoles (thiabendazole, albendazole, fenbendazole, mebendazole, oxfendazole) in animal feeds was developed. Separation was carried out in an 80.5 cm x 75 microm id fused-silica uncoated capillary and injected by hydrodynamic injection (35 mbar x 8 s) at a wavelength detection of 295 nm. The drugs were completely resolved in 50 mmol/L citric acid buffer (pH 1.9) with 30 kV at a temperature of 25 degrees C. Linear range was 1-80 microg/mL; limits of detection for the analytes were less than 2 mg/kg; the overall recoveries for benzimidazoles were >73%, with coefficients of variation below 10%.


Assuntos
Ração Animal/análise , Benzimidazóis/análise , Tampões (Química) , Cromatografia Líquida de Alta Pressão , Eletroforese Capilar , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Preparações Farmacêuticas/análise , Padrões de Referência
17.
Se Pu ; 26(6): 755-8, 2008 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-19253559

RESUMO

A high performance capillary electrophoresis (HPCE) method has been established for the separation of melamine in milk and milk powder. The separation was carried out on a fused-silica uncoated capillary column (58.5 cm x 75 microm). The sample was injected by hydrodynamic injection (3.5 kPa (35 mbar) x 8 s) at a temperature of 25 degrees C. The analysis was completed in about 6 min in 40 mmol/L Na2HPO4-20 mmol/L citric acid buffer (pH 2.6) at 25 kV of separation voltage and 232 nm of detection wavelength. The linear range of melamine was 1 - 100 mg/kg, and the correlation coefficient was higher than 0. 997. The limits of quantification (LOQs) in milk and milk powder were 0.5 mg/kg and 1.0 mg/kg, respectively. The average recoveries were in the range of 72.2% -97.3% in the spiked range of the concentration of LOQs and 50 mg/kg, and the relative standard deviations were between 2.1% and 3.9%.


Assuntos
Eletroforese Capilar/métodos , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Fórmulas Infantis/química , Leite/química , Triazinas/análise , Métodos Analíticos de Preparação de Amostras , Animais , Tampões (Química) , Calibragem , Limite de Detecção , Pós , Triazinas/isolamento & purificação
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