Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Artigo em Inglês | MEDLINE | ID: mdl-32618500

RESUMO

Amygdalin, prunasin, total cyanide and free cyanide concentrations in 12 powdered loquat seeds were investigated. Loquat (Eriobotrya japonica) is a species of flowering plant in the family Rosaceae, and its fruit is quite popular in Japan. Amygdalin and prunasin were measured using LC-MS/MS. Total cyanide was measured by enzymatic treatment, steam distillation and colorimetric quantification using the pyridine-pyrazolone method. Free cyanide was measured without enzymatic treatment. The mean concentrations of amygdalin, prunasin, total cyanide and free cyanide in powdered loquat seeds were 5900, 760, 410 and 44 mg/kg, respectively. The range of each quantitative value was extensive. Seven out of twelve samples were at risk for exceeding the acute reference dose (ARfD) of cyanide.

2.
Artigo em Inglês | MEDLINE | ID: mdl-32515305

RESUMO

In this study, we developed a reference labelled protein containing the partial amino acid sequence of botulinum neurotoxin type A (BoNTA). We also applied it as an internal standard to detect specific and non-toxic peptides originated from BoNTA in honey with the use of liquid chromatography-tandem mass spectrometry (LC-MS/MS). Original proteins in the honey sample were collected through a two-step process that included solubilisation and trichloroacetic acid (TCA) precipitation. Solubilisation by adding water enabled processing of proteins in honey. TCA precipitation collected proteins without specific binding. The combination of protein alkylation and an appropriate enzyme-to-protein ratio ensured feasibility of tryptic digestion. A desalting process eliminated a large amount of salts and other tryptic peptides in the honey sample. The use of the reference labelled protein enabled compensation for tryptic digestion efficiency and electrospray ionisation efficiency based on LC-MS/MS measurement. After the peptide selection and protein BlastP analysis, five unique peptides were chosen. The non-toxic peptides originating from BoNTA were reliably detected using LC-MS/MS based on a multiple-reaction monitoring mode. Detection of several peptides ensured screening of BoNTA in honey samples. Based on the responses, the proteotypic peptide LYGIAINPNR was selected as the quantitative peptide. Due to maintaining the relative ion ratios, the selective transition completely identified the non-toxic peptides. The intensity of the transitions established a detection limit of BoNTA estimated to be 9.4 ng mL-1. Although extraction efficiency was not evaluated using the BoNTA standard, the results suggested this method may be used for quantification of BoNTA in honey. The method was applied to 19 honey samples purchased in Tokyo; none of them was found to contain the target toxin. Overall, the method is expected to accelerate BoNTA monitoring for food safety.

3.
Shokuhin Eiseigaku Zasshi ; 60(3): 52-60, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-31391411

RESUMO

We developed an analytical method for determining 15 antifungal drugs, 2 antiparasitic drugs, and 3 veterinary drugs in fish and livestock products using LC-MS/MS. First, 50% ethanol was added to their products, and the mixture was homogenized to reduce drug degradation. Thereafter, 20 drugs were extracted from the pretreated sample mixture using acetonitrile. Cleanup was performed using an alumina-N SPE cartridge. Finally, chromatographic separation was performed using a fully porous octadecyl silanized silica column. The new method is applicable to fish in which the matrix hampers accurate analysis. It was validated on 8 fish and livestock products. Drug recovery rates ranged from 70.2 to 109.3%, RSDs of repeatability were <18.0%, and RSDs of within-laboratory reproducibility were <18.7%. It fulfills the Japanese guideline criteria. The limits of quantification were estimated as 3 ng/g.


Assuntos
Antifúngicos/análise , Contaminação de Alimentos/análise , Carne/análise , Alimentos Marinhos/análise , Drogas Veterinárias/análise , Animais , Cromatografia Líquida , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem
4.
Artigo em Inglês | MEDLINE | ID: mdl-31094669

RESUMO

In this study, the staphylococcal enterotoxin type A (SEA) contaminant was quantified in cow milk by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with the use of a stable isotope-labelled peptide of SEA as an internal standard. SEA was cleaned up in a two-step process that included pH control and trichloroacetic acid (TCA) precipitation. The pH control phase eliminated other proteins. TCA precipitation cleaned up SEA without special equipment. An appropriate enzyme-to-protein ratio maximised tryptic digestion. A desalting process guaranteed the stable retention of SEA-digested peptides. The coverage of amino-acid sequences (>10%) clearly identified the toxin's presence. SEA was accurately quantified using LC-MS/MS based on a multiple-reaction monitoring mode. The developed method was validated based on spiked recovery tests at 50 and 100 µg kg-1 conducted with two samples collected on a daily basis for five days based on Japanese validation guidelines. The new method exhibited good accuracy which ranged from 80% to 82%. The relative standard deviations of repeatability were 13-14% and the relative standard deviations of within-laboratory reproducibility were 13-18%. These standard deviations satisfied the criteria of the Japanese validation guidelines. The quantification limit was estimated to be 10 µg kg-1.


Assuntos
Enterotoxinas/análise , Contaminação de Alimentos/análise , Leite/química , Peptídeos/química , Animais , Bovinos , Cromatografia Líquida , Marcação por Isótopo , Espectrometria de Massas em Tandem
5.
Artigo em Inglês | MEDLINE | ID: mdl-31100042

RESUMO

In this study, a new method was developed for simultaneously determining nine preservatives, that is, benzoic acid (BA), sorbic acid (SOA), dehydroacetic acid (DHA) and PHBAs (methyl p-hydroxybenzoate [PHBA-me], ethyl p-hydroxybenzoate [PHBA-et], isopropyl p-hydroxybenzoate [PHBA-ipro], propyl p-hydroxybenzoate [PHBA-npro]), isobutyl p-hydroxybenzoate [PHBA-ibut] and butyl p-hydroxybenzoate [PHBA-nbut]), in processed foods, employing liquid chromatography (LC). This procedure accelerated sample preparation and improved efficiency by employing modified quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction without clean-up. Samples were prepared with 20 mL of acetonitrile/water (1:1) with the assistance of a ceramic stone. The extract solutions were diluted 10 times or according to the detection amount and then injected into an LC-PDA. This method showed good linearity, and the LOQs were 10 mg/kg for BA, SOA and DHA and 5 mg/kg for the PHBAs. When validating this method, the recoveries of the nine preservatives were in the range 77.0-99.6%, RSDr values were in the range 0.7-5.3% and those of RSDwr were in the range 2.3-8.4%. These results suggest that this new method is highly reproducible.


Assuntos
Conservantes de Alimentos/análise , Extração em Fase Sólida , Cromatografia Líquida de Alta Pressão
6.
Artigo em Inglês | MEDLINE | ID: mdl-30475679

RESUMO

In this study, the presence of cereulide in cow's milk was identified and quantified using our validated method with liquid chromatography-tandem mass spectrometry. Cereulide was concentrated using protein acid-precipitation and extracted from the precipitate by using acetonitrile twice. The combination of protein acid-precipitation and extraction sufficiently eliminated the matrix compounds from the milk and a further clean-up step utilising solid-phase extraction could be omitted. For robustly measuring the samples and keeping the MS devices clean, the extraction solution was diluted 10-fold using methanol. Owing to the minimisation of the interferences caused by fragmentation patterns, multiple reaction monitoring information-dependent acquisition-enhanced product ion spectra enabled the characterisation and identification of cereulide. Besides the matrix effect (-4%), an external solvent calibration curve was adapted for accurate quantification. The method was validated using fortified recovery tests, at two concentrations (10 and 50 µg kg-1), using three samples daily on five different days based on the Japanese guidelines. This new method exhibited good accuracy ranging from 91% to 94%. The relative standard deviations of repeatability ranged from 2% to 5%, and the relative standard deviation of within-laboratory reproducibility ranged from 5% to 6%. These standard deviations satisfied the criteria for the Japanese validation guidelines. The limit of quantification (LOQ) was estimated to be 2 µg kg-1. On the product ion spectra at the LOQ level, the library match was satisfactory with a purity fit value of >70%. The method was applied to 14 raw milk and three milk samples pasteurised using the low-temperature, long-time process and collected in Tokyo. None of the samples was found to contain the target toxin.


Assuntos
Depsipeptídeos/análise , Contaminação de Alimentos/análise , Leite/química , Animais , Calibragem , Bovinos , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas em Tandem
7.
Artigo em Inglês | MEDLINE | ID: mdl-30427268

RESUMO

We developed a method for the simultaneous determination of acaricides in comb honey using LC/MS/MS. Because methods for honey analysis had not previously been applied to comb honey, we modified three techniques for sample preparation and LC/MS/MS conditions. First, we used a modified QuEChERS method that changed the extraction solution from ethyl acetate to acetonitrile. Second, we replaced the InertSep® MA-1 (30 mg, 1 ml) clean-up cartridge with an Oasis® HLB (60 mg, 3 ml). Third, we changed the ionisation mode from ESI to atmospheric pressure chemical ionisation (APCI). With these modifications, sample matrices had no effect on the identification and quantification of analytes, using an external solvent calibration curve. We verified this new method with nine acaricides and two metabolites on comb honey and honey samples from three different honey origins. The trueness ranged from 74.0 to 99.4%. The relative standard deviation of repeatability (RSDr) ranged from 0.8 to 14.8% and that of within-laboratory reproducibility (RSDWR) ranged from 1.3 to 14.8%. All criteria met Japanese validation guidelines. The LOQ was 1.0 µg kg-1 for all analytes. We applied this method to 10 comb honey and 31 honey samples commercially available in Tokyo. From the results of the analysis of 41 samples, we observed that amitraz remained as N-(2,4-dimethylphenyl)-N-methylformamidine (DMPF) in 9 comb honey and 23 honey samples and that their residual concentrations were less than 20 µg kg-1. Using this new method, we improved recovery and precision, which enabled precise quantitative determination. Furthermore, the residual amitraz value in honey determined by both this new and the previous method were in good agreement.


Assuntos
Acaricidas/análise , Mel/análise , Acaricidas/metabolismo , Cromatografia Líquida , Espectrometria de Massas em Tandem
8.
Shokuhin Eiseigaku Zasshi ; 59(4): 174-182, 2018.
Artigo em Japonês | MEDLINE | ID: mdl-30158396

RESUMO

Colchicum autumnale is a perennial, toxic plant that originated in Europe and North Africa. Although inedible, it is occasionally consumed accidentally because it resembles the edible Allium victorialis and other related species. This misidentification has led to episodes of food poisoning in Japan. However, determining the causative agent of a food poisoning outbreak by observing the sample visually or analyzing the chemical composition is challenging when dealing with small samples. Therefore, we developed a novel set of PCR primers that anneal to the internal transcribed spacer (ITS) region of C. autumnale ribosomal DNA, designed to detect the presence of C. autumnale in small samples. These primers successfully detected C. autumnale in all samples in which it was present, and did not give a positive PCR band in the 48 other distinct crop species tested, in which it was not present. Further, our method could amplify DNA from samples of C. autumnale that had been heat-treated and digested using artificial gastric fluids. Thus, this PCR strategy is highly specific and can be used to distinguish C. autumnale simply and rapidly from various other crops.


Assuntos
Colchicum/classificação , DNA de Plantas/isolamento & purificação , Doenças Transmitidas por Alimentos/diagnóstico , Primers do DNA , DNA Espaçador Ribossômico/genética , Humanos , Japão , Reação em Cadeia da Polimerase
9.
Shokuhin Eiseigaku Zasshi ; 58(1): 32-35, 2017.
Artigo em Japonês | MEDLINE | ID: mdl-28260730

RESUMO

Kuwazuimo (Alocasia odora) and shimakuwazuimo (Alocasia cucullata) are evergreen perennial plants that originated in East Asia. Although inedible, they are occasionally eaten by mistake because they resemble satoimo (Colocasia esculenta), and this has caused food poisoning in Japan. It is not easy to determine the cause of a food poisoning outbreak from the shape or chemical composition when the available sample is small. Therefore, we developed a new primer pair for PCR to identify kuwazuimo and shimakuwazuimo in small samples, based on the internal transcribed spacer (ITS) region of ribosomal DNA. Using PCR with the developed primer pair, we detected all samples of kuwazuimo obtained from the market, while excluding 17 other kinds of crops. The samples were identified as shimakuwazuimo by DNA sequencing of the PCR products. The present PCR method showed high specificity and was confirmed to be applicable to the identification of kuwazuimo and shimakuwazuimo from various crops.


Assuntos
Alocasia/química , Alocasia/genética , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Reação em Cadeia da Polimerase/métodos , Alocasia/envenenamento , DNA Ribossômico , Doenças Transmitidas por Alimentos/etiologia , Doenças Transmitidas por Alimentos/prevenção & controle , Sensibilidade e Especificidade , Análise de Sequência de DNA
10.
Shokuhin Eiseigaku Zasshi ; 58(1): 49-58, 2017.
Artigo em Japonês | MEDLINE | ID: mdl-28260733

RESUMO

A survey of nitrate-ion concentrations in plant-factory-cultured leafy vegetables was conducted. 344 samples of twenty-one varieties of raw leafy vegetables were examined using HPLC. The nitrate-ion concentrations in plant-factory-cultured leafy vegetables were found to be LOD-6,800 mg/kg. Furthermore, the average concentration values varied among different leafy vegetables. The average values for plant-factory-cultured leafy vegetables were higher than those of open-cultured leafy vegetables reported in previous studies, such as the values listed in the Standard Tables of Food Composition in Japan- 2015 - (Seventh revised edition). For some plant-factory-cultured leafy vegetables, such as salad spinach, the average values were above the maximum permissible levels of nitrate concentration in EC No 1258/2011; however, even when these plant-factory-cultured vegetables were routinely eaten, the intake of nitrate ions in humans did not exceed the ADI.


Assuntos
Agricultura/métodos , Análise de Alimentos/métodos , Nitratos/análise , Verduras/química , Cromatografia Líquida de Alta Pressão , Íons
11.
Shokuhin Eiseigaku Zasshi ; 57(4): 89-95, 2016.
Artigo em Japonês | MEDLINE | ID: mdl-27558226

RESUMO

An analytical method for the determination of fluopicolide in livestock products and seafood was developed using LC-MS/MS. Sodium chloride was added to livestock products and seafood samples and fluopicolide was extracted twice with acetone after acidification with formic acid. The fat from the crude extract was removed using a macroporous diatomaceous earth column, followed by purification with a combination of mini-columns of GC (graphite carbon) and PSA (ethylenediamine-N-propyl silylation silica gel). The average recovery (n=5) of fluopicolide from 10 types of livestock products and seafood (cattle fat, cattle liver, cattle muscle, chicken, eel, egg, freshwater clam, honey, milk and salmon) spiked at the MRLs or at the uniform limit (0.01 ppm) was 96-100%, with a relative standard deviation of 2.3-6.2%. The limit of quantitation of the developed method was calculated to be 0.01 mg/kg.


Assuntos
Benzamidas/análise , Cromatografia Líquida/métodos , Análise de Alimentos/métodos , Fungicidas Industriais/análise , Gado , Produtos da Carne/análise , Resíduos de Praguicidas/análise , Alimentos Marinhos/análise , Espectrometria de Massas em Tandem/métodos , Animais , Benzamidas/isolamento & purificação , Bovinos , Galinhas , Ovos/análise , Fungicidas Industriais/isolamento & purificação , Mel/análise , Leite/química , Resíduos de Praguicidas/isolamento & purificação
12.
J AOAC Int ; 98(1): 230-47, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25857903

RESUMO

Residues of 37 polar veterinary drugs belonging to six families (quinolones, tetracyclines, macrolides, lincosamides, sulfonamides, and others) in livestock and fishery products were determined using a validated LC-MS/MS method. There were two key points in sample preparation. First, extraction was performed with two solutions of different polarity. Highly polar compounds were initially extracted with Na2EDTA-McIlvaine's buffer (pH 7.0). Medium polar compounds were then extracted from the same samples with acetonitrile containing 0.1% formic acid. Secondly, cleanup was performed using a single SPE polymer cartridge. The first extracted solution was applied to the cartridge. Highly polar compounds were retained on the cartridge. Then, the second extracted solution was applied to the same cartridge. Both highly and medium polar compounds were eluted from the cartridge. This method satisfied the guideline criteria for 37 out of 37 drugs in swine muscle, chicken muscle, bovine muscle, prawn, salmon trout, red sea bream, milk, and honey; 35 out of 37 in egg; and 34 out of 37 in flounder. The LOQ ranged from 0.1 to 5 µg/kg. Residues were detected in 24 out of 110 samples and analyzed using the validated method.


Assuntos
Cromatografia Líquida/veterinária , Resíduos de Drogas/química , Produtos Pesqueiros/análise , Músculo Esquelético/química , Espectrometria de Massas em Tandem/veterinária , Drogas Veterinárias/química , Animais , Cromatografia Líquida/métodos , Ovos/análise , Mel/análise , Leite/química , Espectrometria de Massas em Tandem/métodos
13.
Shokuhin Eiseigaku Zasshi ; 56(1): 19-30, 2015.
Artigo em Japonês | MEDLINE | ID: mdl-25748982

RESUMO

We performed a single-laboratory validation study of a simple and simultaneous determination method for pesticide residues in meat using LC-MS/MS. Water was added to the sample and the mixture was homogenized. Next, pesticides were extracted with acetonitrile containing 1 vol% formic acid using a homogenizer, and salted out with magnesium sulfate, trisodium citrate and sodium chloride. After centrifugation, the acetonitrile layer was made up to standard volume and analyzed by LC-MS/MS. This method was assessed by performing recovery tests in retail bovine, swine and chicken muscle samples spiked with the 132 pesticides at the levels of 0.01 and 0.04 µg/g. Among them, 125 pesticides satisfied the Japanese method validation guideline criteria in bovine, 120 in swine and 127 in chicken.


Assuntos
Cromatografia Líquida/métodos , Análise de Alimentos/métodos , Carne/análise , Resíduos de Praguicidas/isolamento & purificação , Espectrometria de Massas em Tandem/métodos , Acetonitrilos , Animais , Bovinos , Galinhas , Cromatografia Líquida/instrumentação , Análise de Alimentos/instrumentação , Guias como Assunto , Japão , Suínos , Espectrometria de Massas em Tandem/instrumentação
14.
Shokuhin Eiseigaku Zasshi ; 55(6): 254-60, 2014.
Artigo em Japonês | MEDLINE | ID: mdl-25743588

RESUMO

Rapid multi-residue analysis of pesticides in agricultural products was studied by using LC-MS/MS. Pesticide residues in 10 g of homogenized agricultural products were extracted with 30 mL of acetonitrile and salted out with 4 g of anhydrous magnesium sulfate and 1 g of sodium chloride in the presence of citrate salts for buffering in a disposable tube. Co-extractives were removed by use of our original triple layered column (C18/GC/PSA; 60/30/60 mg). According to the method validation guideline of the Ministry of Health, Labour and Welfare of Japan, we conducted recovery tests in 5 kinds of agricultural products (brown rice, kiwi, cabbage, sweet potato and spinach) spiked with 60 pesticides at the level of 0.01 or 0.1 µg/g. Each concentration of pesticide spiked was extracted from 2 samples per day on 5 days. Pesticides in the test solution were determined by two types of LC-MS/MS using scheduled MRM. Using this method, 58 out of 60 pesticides satisfied the guideline criteria in brown rice, 59 in kiwi, 55 in cabbage, 55 in sweet potato and 56 in spinach. This method is applicable for routine examination of pesticide residues in agricultural products.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Produtos Agrícolas/química , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Resíduos de Praguicidas/análise , Espectrometria de Massas em Tandem/métodos
15.
Shokuhin Eiseigaku Zasshi ; 54(4): 335-44, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24025214

RESUMO

A method of rapid analysis of multi-class residual veterinary drugs in milk, fish and shellfish was validated in accordance with Japanese guidelines for the validation of analytical methods for residual agricultural chemicals in food. Using LC-MS/MS, 43 multi-class veterinary drugs, including sulfonamides, quinolones, coccidiostats and antiparasites, could be analyzed in one injection. Analytes were extracted from samples with two kinds of solvent, acetonitrile containing 1 vol% formic acid and anhydrous acetonitrile, and salted out with 4.0 g of magnesium sulfate, 1.5 g of trisodium citrate and 2.0 g of sodium chloride. This method was assessed by performing recovery tests in retail milk and 4 kinds of fresh cultured fish and shellfish (salmon, tiger shrimp, red sea bream and bastard halibut) spiked with the 43 target analytes at the levels of 10 and 100 µg/kg. Using this method, 40 out of 43 drugs satisfied the guideline criteria in milk, 37 drugs in salmon, 42 drugs in tiger shrimp, 41 drugs in red sea bream and 39 drugs in bastard halibut.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Resíduos de Drogas/análise , Produtos Pesqueiros/análise , Peixes/metabolismo , Análise de Alimentos/métodos , Análise de Alimentos/normas , Contaminação de Alimentos/análise , Leite/química , Frutos do Mar/análise , Espectrometria de Massas em Tandem/métodos , Drogas Veterinárias/análise , Animais , Guias como Assunto/normas , Japão
16.
Shokuhin Eiseigaku Zasshi ; 53(5): 243-53, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23154765

RESUMO

A method for rapid analysis of multi-class residual veterinary drugs in livestock products was developed and validated in accordance with the Japanese guideline for pesticides. Using LC-MS/MS, 43 multi-class veterinary drugs, including sulfonamides, quinolones, coccidiostats and antiparasites, could be analyzed simultaneously in only 18 minutes. The extraction process was developed by modifying the QuEChERS approach to provide faster and less expensive extraction. The samples were extracted by using two kinds of solvent, acetonitrile and acetonitrile including 1 vol% formic acid, and salted out with magnesium sulfate, trisodium citrate and sodium chloride. Using these two extractants, 40 out of 43 drugs satisfied the guideline criteria in bovine muscle and swine muscle, 39 drugs were found in chicken muscle, and 37 drugs were found in eggs. The limit of quantification was less than the MRL for all analytes.


Assuntos
Cromatografia Líquida , Carne/análise , Espectrometria de Massas em Tandem , Drogas Veterinárias/análise , Animais , Bovinos , Galinhas , Ovos/análise , Músculos/química , Suínos
17.
J AOAC Int ; 95(3): 923-31, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22816283

RESUMO

We developed a rapid and efficient means of determining residues of four nitroimidazoles-i.e., dimetridazole, ipronidazole, metronidazole, and ronidazole-and three hydrophilic metabolites- i.e., 2-hydroxymethyl-1-methyl-5-nitroimidazole, 1 -methyl-2-(2'-hydroxyisopropyl)-5-nitroimidazole, and 1-(2-hydroxyethyl)-2-hydroxymethyl-nitroimidazole--in honey. We applied a QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) procedure improved to suit a nitroimidazole analysis, which is fast (approximately 30 min) and uses less organic solvent. The procedure involves initial single-phase extraction of 5 g of honey with acetonitrile containing 1% acetic acid, followed by liquid-liquid partitioning involving the addition of 5 g sodium chloride, 1.5 g trisodium citrate dihydrate, and 4 g magnesium sulfate. Moreover, matrix from honey was reduced by an SPE method with an alumina-N cartridge. The samples were analyzed using LC/MS/MS. Chromatographic separation of these nitroimidazoles and metabolites was performed in the gradient mode on a pentafluorophenylpropyl-bonded silica column (150x2.0 mm, 3 pm particle size) at 40 degrees C. The mobile phase consisted of a 0.01% acetic acid solution and acetonitrile, and the flow rate was 0.2 mL/min. The method was validated using honey spiked with these nitroimidazoles from 0.1 to 0.5 microg/kg. The overall recovery of the seven nitroimidazoles ranged from 76.1 to 98.5%; intra- and interassay CV values were <9.5 and <14.2%, respectively. The LOQ ranged from 0.1 to 0.5 microg/kg. LC/MS/MS coupled with the QuEChERS method showed good potential as a method for determining nitroimidazole residues in honey.


Assuntos
Cromatografia Líquida/métodos , Mel/análise , Nitroimidazóis/análise , Espectrometria de Massas em Tandem/métodos , Calibragem , Contaminação de Alimentos , Limite de Detecção
18.
Shokuhin Eiseigaku Zasshi ; 53(2): 91-7, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22688024

RESUMO

A LC-MS/MS screening assay of multi-class antibiotics was developed for 19 residual antibiotics in livestock samples. Sample preparation employed the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) approach using 0.5% formic acid in acetonitrile-methanol (8 : 2), with salting-out using magnesium sulfate, trisodium citrate and sodium chloride. Recovery values from 5 different livestock samples ranged from 45.5 to 121.6%, and the RSDs were under 18% at two concentration levels. The limit of quantification values of 19 analytes were under 10 µg/kg in all livestock samples, and the procedure can detect almost all analytes under the MRL. Screening capability was confirmed by employing spiked samples. This new screening assay for residual antibiotics in livestock samples is expected to be useful for routine laboratory tests.


Assuntos
Antibacterianos/análise , Cromatografia Líquida de Alta Pressão/métodos , Resíduos de Drogas/análise , Ovos/análise , Análise de Alimentos/métodos , Carne/análise , Leite/química , Espectrometria de Massas em Tandem/métodos , Animais , Bovinos , Galinhas , Suínos
19.
Shokuhin Eiseigaku Zasshi ; 52(3): 178-82, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21720123

RESUMO

We studied the simultaneous determination of nequinate and buquinolate, which are used as feed additives to prevent coccidiosis, by means of liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The sample was extracted with acetonitrile, then loaded onto an HLB mini-column with 20% methanol. After clean-up with 20% methanol, the analytes were eluted with acetonitrile-methanol (1 : 1). The coccidiostats in the purified samples were determined using ESI-MRM mode LC-MS/MS with a sample matrix calibration curve. Mean recoveries of nequinate and buquinolate from 8 kinds of livestocks samples (chicken muscle, chicken liver, chicken heart, swine muscle, swine heart, cattle muscle, sheep muscle, egg) were in the range of 89.5% to 108.6%, and the relative standard deviation values were <20% (n=10) at the levels of 0.01 µg/g and 0.05 µg/g, respectively. The limits of quantification of these compounds were 0.001 µg/g in each sample.


Assuntos
Coccidiostáticos/análise , Hidroxiquinolinas/análise , Produtos da Carne/análise , Quinolonas/análise , Animais , Bovinos , Galinhas , Cromatografia Líquida , Ovos/análise , Ovinos , Suínos , Espectrometria de Massas em Tandem
20.
J AOAC Int ; 94(3): 878-85, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21797017

RESUMO

A new, rapid, and efficient method for determining the fumagillin residues in honey was developed. The samples extracted were analyzed using LC/MS/MS. Chromatographic separation of fumagillin was performed in gradient mode on a C8 column (100 x 2.0 mm, 5 microm) at 40 degrees C. The mobile phase consisted of a mixture of 2 mM ammonium formate-0.01% formic acid solution and methanol; the flow rate was set to 0.2 mL/min. Under these conditions, it was possible to measure fumagillin and its isomers as a single peak. The sample preparation procedure used is based on the QuEChERS (quick, easy, cheap, effective, rugged, and safe) method, which is fast (approximately 30 min) and uses less organic solvent. The fumagillin was extracted with acetonitrile containing 0.1% formic acid, then purified using a solid-phase extraction method with an Oasis mixed-mode weak anion-exchange cartridge. The overall recovery of fumagillin ranged from 88.1 to 99.4%; the intra- and interassay CVs were <4.5% and <4.9%, respectively. The LOQ was 0.1 microg/kg. LC/MS/MS coupled with the QuEChERS method showed strong potential as a method for determining fumagillin residues in honey.


Assuntos
Antibacterianos/química , Cromatografia Líquida/métodos , Cicloexanos/química , Ácidos Graxos Insaturados/química , Mel/análise , Espectrometria de Massas em Tandem/métodos , Contaminação de Alimentos , Estrutura Molecular , Reprodutibilidade dos Testes , Sesquiterpenos/química , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA