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1.
Food Chem Toxicol ; 135: 110931, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31678486

RESUMO

This study evaluated the heterocyclic aromatic amine (HAA) contents and quality characteristics of seven kinds of traditional smoked and roasted poultry products on the northern Chinese market. Harbin smoked chicken had the most abundant total HAAs, followed by Haroulian roasted chicken and Yishou smoked chicken. The contents of Norharman and Harman were much higher than those of other kinds of HAAs (P < 0.05). The water content of samples varied from 59.01% to 69.98% and the water activity varied from 0.953 to 0.976. The carbonyl content and TBARS values of the Beijing roasted duck and the Duiqing roasted goose were much higher than those of the other samples (P < 0.05). The sensory evaluation result of the Beijing roasted chicken was higher than that of the other samples (P < 0.05). Overall, the levels of HAAs in the industrial smoked and roasted products were lower than those in non-industrial products, which may provide a theoretical basis for the industrial production of smoked and roasted poultry products.


Assuntos
Aminas/análise , Qualidade dos Alimentos , Compostos Heterocíclicos com 2 Anéis/análise , Compostos Heterocíclicos com 3 Anéis/análise , Produtos Avícolas/análise , Animais , Galinhas , China , Culinária , Patos , Gansos , Análise de Componente Principal , Substâncias Reativas com Ácido Tiobarbitúrico/análise
2.
Artigo em Inglês | MEDLINE | ID: mdl-31887557

RESUMO

Azo dyes can metabolize back to precursor aromatic amines (arylamines), which are potentially carcinogenic. The ISO 14362-1:2017 standard requires the determination of the arylamines, produced from textile samples, preferably by using the gas chromatography mass spectrometric (GC-MS) method. This paper presents an ion-pairing high performance liquid chromatography tandem mass spectrometric (LC-MS/MS) method for determining aromatic amines, derived from azo colorants, in both natural and synthetic textiles. The separation enables adequate apparent retention factor (k' > 2.1 for the most hydrophilic compounds) and has appropriate sensitivity without sample clean-up procedure. The background matrix constituents influence the quantification in even a 100-fold diluted sample, therefore, calibration requires background compensation. The method allows fast confirmation and quantification of twenty-five arylamines in complex matrices of textiles. The method was validated with success and used to both natural and synthetic textile proficiency test (PT) samples.


Assuntos
Aminas/análise , Compostos Azo/análise , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Aminas/química , Compostos Azo/química , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes , Têxteis
3.
Food Chem ; 309: 125651, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31678674

RESUMO

The effects of low frequency magnetic field on myoglobin (Mb) oxidation stability were evaluated by treatments at 0, 3, 6, 9, 12 mT and storage for 10 h. The results showed that Mb oxidation was inhibited under all magnetic field treatments, due to the increase of total sulfhydryl and free amino groups (9 or 12 mT) from unfolding of Mb clusters (3, 9, 12 mT) as well as ß-turn and ß-sheet structures (9 or 12 mT). The unfolding also induced (i) the destruction or burial of iron porphyrin and tyrosine residues; (ii) the exposure of tryptophan; (iii) more uniform Mb particle size distribution (3, 9, 12 mT) and increased zeta potential (3, 6, 12 mT). Overall, magnetic field promoted exposed active groups as the preferred oxidation target, thus decreasing the oxidation rate of central iron atoms. It also promoted Mb stability by redistributing particle size and increasing zeta potential.


Assuntos
Mioglobina/química , Aminas/análise , Campos Magnéticos , Oxirredução , Tamanho da Partícula , Conformação Proteica em Folha beta , Estabilidade Proteica , Desdobramento de Proteína , Compostos de Sulfidrila/análise
4.
Food Chem ; 302: 125326, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31416003

RESUMO

Ruminant meat is considered an excellent source of proteins, dietary fatty acids and essential minerals. Grilling is a popular cooking method; however, the high temperatures employ could modify the grilled meat quality and safety. In this study, the effects of novel beer-based marinades infused with herbs and spices on the quality, safety, and sensory perception of grilled beef and moose meat is examined. Unmarinated meat showed high content of volatile lipid oxidation and Maillard reaction products compared to the marinated samples, which contained higher number and abundance of terpenes and sulfur based compounds. Strong relationships between Maillard products and heterocyclic amines formation, as well as between volatile terpenes and the lipophilic antioxidant activity, were observed in the grilled meats. The findings suggest the unfiltered beer-based marinades were effective in reducing lipid oxidation and Maillard reaction compounds formation, while improving the nutritional quality, safety and sensory preference of grilled ruminant meats.


Assuntos
Cerveja , Culinária/métodos , Carne , Ruminantes , Adolescente , Adulto , Aminas/análise , Aminas/química , Animais , Bovinos , Qualidade dos Alimentos , Cromatografia Gasosa-Espectrometria de Massas , Compostos Heterocíclicos/análise , Temperatura Alta , Humanos , Reação de Maillard , Carne/análise , Pessoa de Meia-Idade , Valor Nutritivo , Carne Vermelha , Especiarias , Paladar , Compostos Orgânicos Voláteis/análise
5.
Top Curr Chem (Cham) ; 378(1): 5, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31823121

RESUMO

Over the past two decades, metal-organic frameworks (MOFs) with flexible structures or dynamic behavior have shown great potential as functional materials in many fields. This paper presents a review of these dynamic and functional MOFs, which can undergo controllable and reversible transformation, with regard to their application as smart switches. Trigger conditions, which include physical/chemical stimuli (e.g., guest molecules, light, temperature, pressure), are also discussed. Research methods for investigating the dynamic processes and mechanisms involving experimental characterization and computational modeling are briefly mentioned as well. The emphasis is on the aspects of the design and functionalization of dynamic MOFs. The pre-design of metal nodes, organic linkers, and topology, as well as post-modification of components, increases the possibility of obtaining functionalized dynamic materials. Recent advances with regard to potential applications for dynamic frameworks as smart switches for adsorption and sensing are also reviewed.


Assuntos
Estruturas Metalorgânicas/química , Adsorção , Aminas/análise , Gases/análise , Luz , Estruturas Metalorgânicas/efeitos da radiação , Pressão , Solventes/química , Temperatura Ambiente
6.
Shokuhin Eiseigaku Zasshi ; 60(3): 61-67, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-31391412

RESUMO

A method was developed for the determination of nonvolatile amines, such as histamine, tyramine, putrescine, and cadaverine, in foods. These nonvolatile amines were extracted from a sample with 5% trichloroacetic acid, and the extract was purified using an InertSep MC-1 cartridge column. The four amines were derivatized with fluorescamine, determined by HPLC with a fluorescence detector, and confirmed by LC-MS/MS. The average recoveries (n=5) and the relative standard deviations from 11 foods (pacific saury, dried mackerel, canned mackerel in brine, canned tuna in oil, fish sauce, surimi, rice-koji miso, soy sauce, gouda cheese, red wine, and beer) spiked at 100 mg/kg were 81-100% and 0.4-3.1%, respectively.


Assuntos
Aminas/análise , Fluorescamina , Análise de Alimentos/métodos , Animais , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas em Tandem
7.
Anal Chim Acta ; 1079: 220-229, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31387715

RESUMO

We developed temperature-responsive mixed-mode columns packed with poly(N-isopropylacrylamide) (PNIPAAm)-modified beads and poly(2-acrylamido-2-methylpropane sulfonic acid) (PAMPS)-modified beads in various ratios. The PNIPAAm-modified silica beads and PAMPS-modified silica beads were prepared by surface-initiated atom transfer radical polymerization of N-isopropylacrylamide and 2-acrylamido-2-methylpropane sulfonic acid, respectively. We confirmed polymer modification of the silica beads by CHN elemental analysis, FTIR, zeta-potential measurements, and SEM. To determine the column separation efficiency, we examined the elution behaviors of cold medicine active ingredients and monoamines from each column. Analyte separation occurred on columns with PNIPAAm to PAMPS ratios of 1:20 and 1:10, whereas a column containing only PNIPAAm-modified beads did not retain the analytes. The analytes were retained on the columns through hydrophobic and electrostatic interactions with PNIPAAm and PAMPS, respectively. The separation performance improved with increasing column temperature because of dehydration of PNIPAAm and enhancement of hydrophobic interactions at elevated temperatures. The mixed-mode columns will be useful for separating basic bioactive compounds because the retention of analytes can be modulated by changing the column temperature and the composition.


Assuntos
Resinas Acrílicas/química , Resinas de Troca de Ânions/química , Cromatografia por Troca Iônica/instrumentação , Polímeros/química , Ácidos Sulfônicos/química , Alcaloides/análise , Aminas/análise , Cromatografia por Troca Iônica/métodos , Compostos Heterocíclicos de Anéis Fundidos/análise , Dióxido de Silício/química , Temperatura Ambiente
8.
J Chromatogr A ; 1602: 386-396, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31285057

RESUMO

A comprehensive Collision Cross Section (CCS) library was obtained via Travelling Wave Ion Guide mobility measurements through direct infusion (DI). The library consists of CCS and Mass Spectral (MS) data in negative and positive ElectroSpray Ionisation (ESI) mode for 463 and 479 endogenous metabolites, respectively. For both ionisation modes combined, TWCCSN2 data were obtained for 542 non-redundant metabolites. These data were acquired on two different ion mobility enabled orthogonal acceleration QToF MS systems in two different laboratories, with the majority of the resulting TWCCSN2 values (from detected compounds) found to be within 1% of one another. Validation of these results against two independent, external TWCCSN2 data sources and predicted TWCCSN2 values indicated to be within 1-2% of these other values. The same metabolites were then analysed using a rapid reversed-phase ultra (high) performance liquid chromatographic (U(H)PLC) separation combined with IM and MS (IM-MS) thus providing retention time (tr), m/z and TWCCSN2 values (with the latter compared with the DI-IM-MS data). Analytes for which TWCCSN2 values were obtained by U(H)PLC-IM-MS showed good agreement with the results obtained from DI-IM-MS. The repeatability of the TWCCSN2 values obtained for these metabolites on the different ion mobility QToF systems, using either DI or LC, encouraged the further evaluation of the U(H)PLC-IM-MS approach via the analysis of samples of rat urine, from control and methotrexate-treated animals, in order to assess the potential of the approach for metabolite identification and profiling in metabolic phenotyping studies. Based on the database derived from the standards 63 metabolites were identified in rat urine, using positive ESI, based on the combination of tr, TWCCSN2 and MS data.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Mobilidade Iônica/métodos , Espectrometria de Massas/métodos , Metaboloma , Urina/química , Aminas/análise , Animais , Calibragem , Aprendizado de Máquina , Ratos , Padrões de Referência
9.
J Food Sci ; 84(7): 1992-2002, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31264718

RESUMO

A simple, fast, and efficient method, "enhanced matrix removal of lipids" (EMR-lipid), was proposed, optimized, and validated for identifying five polar heterocyclic amines (HCAs) in meat samples that ranged from high-protein (beef and chicken) to high-fat (pork bacon) matrices. The protocol involves an initial solid-liquid phase extraction followed by a rapid dispersive solid-phase extraction using EMR-lipid sorbents and salting-out partitioning. Acetonitrile containing formic acid at two levels (1% and 2%) efficiently extracted HCAs from different meat matrices. Liquid chromatography-tandem mass spectrometry (MS/MS) with selective reaction monitoring mode was developed for qualitative and quantitative analysis. The highest MS/MS responses and better peak separation of analytes were achieved by adjusting mobile phases to pH 3.0 with instrumental detection limits between 0.01 and 0.05 ng/mL. Good linearity of standard curves was obtained in both pure solvents and postspiked meat extracts between 0.5 and 50.0 ng/mL. The validation results showed good precision, accuracy, and sensitivity for detecting HCAs in spiked meat samples. Satisfactory recoveries of four HCAs were achieved: 65% to 111% in beef, 71% to 106% in bacon, and 42% to 77% in chicken. Matrix effects were also assessed and showed less than -20% of ion suppression in bacon extract, while a medium to high signal suppression was observed in beef (-37% to -55%) and chicken (-28% to -52%). This optimized EMR-lipid method provides acceptable results and advantages for determining trace level HCAs in complex meat matrices.


Assuntos
Aminas/análise , Aminas/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Extração Líquido-Líquido/métodos , Carne/análise , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Animais , Bovinos , Galinhas , Contaminação de Alimentos/análise , Suínos
10.
Food Chem ; 298: 125048, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260953

RESUMO

Heterocyclic aromatic amines (HAAs) are harmful by-products naturally formed during the heating process of foodstuffs. The present work reported an analytical method for HAAs analysis for the first time in bakery products by QuEChERS technique combined with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Bakery products were ultrasonically extracted with acetonitrile and sodium hydroxide solution (1 mmol/L). The obtained extracting solution was nearly dried under nitrogen stream and subsequently purified by QuEChERS technique using primary secondary amine (PSA) as adsorbents. Fourteen HAAs were separated on a C18 column with the mobile phase of a mixture of acetonitrile and 1 mmol/L ammonium acetate water solution (containing 0.04% acetic acid), and detected by MS/MS under multiple reaction monitoring (MRM) mode. The developed method was validated in terms of linearity, matrix effect, accuracy and precision. The method showed a good linearity (R2 > 0.999) for all analytes in their corresponding concentration ranges. The method limit of quantifications (LOQs, S/N = 10) of 14 HAAs were in the range of 0.3-4.5 µg/kg. The average recoveries (n = 6) at 3 spiked levels ranged from 62.8 to 96.8% with relative standard deviations (RSDs) of 1.2-7.6%. The validated method was applied in HAAs analysis in 20 bakery products and 4 kinds of HAAs (harman, norharman, AaC, PhIP) were detected with the concentrations ranging from 0.6 to 35.6 µg/kg.


Assuntos
Aminas/análise , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Aminas/química , Pão/análise , Compostos Heterocíclicos/química , Limite de Detecção , Reprodutibilidade dos Testes
11.
Food Chem ; 298: 125020, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260965

RESUMO

Bioactive amines are found in food and can be relevant for the assessment of fruits shelf life and nutritional quality. The pulp and peel of 20 banana and plantain were analyzed and the bioactive amine content varied according to the genotype, ripening stage, fruit tissue and thermal processing. In most of the analyzed genotypes, tyramine, histamine, dopamine, serotonin, spermidine, and spermine were decreased during the ripening process in the pulps. By contrast, there was an increase in putrescine level. In many genotypes of plantains, the serotonin and dopamine contents in pulp decreased until stage 5 and increased at stage 7. Peels contain higher levels of serotonin, dopamine, histamine and tyramine than pulps. Additionally, thermal processing affects the content of amines present in fruit. Boiling with the peel should be preferred in domestic preparations, regardless of the genotype used.


Assuntos
Aminas/análise , Frutas/metabolismo , Musa/metabolismo , Plantago/metabolismo , Aminas Biogênicas/análise , Dopamina/análise , Frutas/química , Genótipo , Histamina/análise , Musa/química , Musa/genética , Plantago/química , Plantago/genética , Putrescina/análise , Serotonina/análise , Espermidina/análise , Espermina/análise , Temperatura Ambiente , Tiramina/análise
12.
Food Chem Toxicol ; 132: 110677, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31310796

RESUMO

In the current investigation, five most potential HAs (MeIQx, 4,8-DiMeIQx, IQ, MeIQ and PhIP) were analyzed in traditional Saudi chicken dishes (shawaya, Ala Al-Faham, kebab, saleeg, mandi, kabsa and madhbi) prepared from local restaurants. The aims of the present study were to identify the presence of HAs in cooked chicken dishes, and to conclude how the levels and types of HAs could be affected by cooking methods and food ingredients. In control samples, HAs were found at higher levels ranged from not quantified to 33.72 ng/g. Nonetheless, in chicken dishes, the HAs (MeIQx, 4,8-DiMeIQx and PhIP) amounts are varied at higher range and relatively detected at lower levels from not quantified to 16.35 ng/g, IQ and MeIQ were not identified in any of the studied chicken dishes except shawaya where found to be not quantified. The HAs reduction rates were obtained at higher values in all of the studied samples, among them mandi sample demonstrates the reduction rates higher than 70%, whereas saleeg sample shows the reduction rates almost 100% except PhIP (~95%). The obtained outcomes have markedly showed that HAs occurrence in thermally processed chicken dishes is extremely affected from both cooking methods and addition of food ingredients.


Assuntos
Aminas/análise , Compostos Heterocíclicos/análise , Mutagênicos/análise , Produtos Avícolas , Aminas/efeitos adversos , Aminas/isolamento & purificação , Animais , Galinhas , Compostos Heterocíclicos/efeitos adversos , Compostos Heterocíclicos/isolamento & purificação , Limite de Detecção , Restaurantes , Arábia Saudita
13.
J Pharm Biomed Anal ; 174: 305-323, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31195319

RESUMO

The use of supplements for weight loss and in sports as pre-workout (ergogenic) products is widespread. Many of these supplements were found to contain active components, which were not claimed on the products labels. A validated liquid chromatography high-resolution mass spectrometry quadrupole time-of-flight (LC-QToF-MS) method was developed for the simultaneous analysis of 111 amine-based compounds belonging to ergogenics, anorectics and other active components including phenethylamines (amphetamines, ephedrines), sibutramine or yohimbine. This method involves the detection of [M+H]+ ions and the separation was achieved using a C18 column, water/acetonitrile gradient as the mobile phase. The method was validated for linearity, repeatability, accuracy, stability, system suitability, limits of quantification (LOQ) and limits of detection (LOD). The limits of detection were in the range from 0.001-0.5 µg/mL. The validated method was applied to the analysis of twenty-seven weight loss and ergogenic dietary supplements. Two-thirds of the supplements contained compounds that were not listed on the product's label. These include several phenethylamines (PEA) such as demelverine, hordenine, N, N-dimethyl-phenethylamine, synephrine, N-methyl-ß-phenethylamine, and methylsynephrine. In addition, the PEA mimics such as dimethylamylamine, dimethylbutylamine other stimulants including fursultiamine, evodiamine, phenibut and theophylline were also observed. One or more of the ingredients listed on the labels were not detected in forty-four percent of the products analyzed. Positive identification was based on retention time, accurate mass and fragment ions in comparison with the respective reference standards. Development of such methods is anticipated to be of aid to regulatory agencies for the identification of undeclared exogenous components that are found in many dietary supplement products.


Assuntos
Fármacos Antiobesidade/análise , Cromatografia Líquida/métodos , Suplementos Nutricionais/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Compostos de Nitrogênio/análise , Substâncias para Melhoria do Desempenho/análise , Aminas/análise , Estimulantes do Sistema Nervoso Central/análise , Elétrons , Íons , Limite de Detecção , Reprodutibilidade dos Testes , Solventes
14.
J Chromatogr A ; 1602: 217-227, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31133424

RESUMO

The aim of this paper is to develop and validate a methodology with potential for routine analysis that allows a fast and easy quantification of 19 primary aromatic amines (PAAs) in acid simulant (3% (w/v) acetic acid aqueous) in food contact materials (FCM). The main reason for studying these amines was the fact that some of them have a carcinogenic factor according to toxicological studies. To validate the method, the parameters linearity, limit of detection (LOD) and limit of quantification (LOQ), precision and accuracy using an UPLC-MS/MS were evaluated. This study also analyzed 36 samples of kitchenware obtained from retail markets: 16 were made of polyamide (PA), one was made of polypropylene (PP) and 19 were made of silicone. The origins of samples were Brazil, China and Turkey. Eleven samples had levels of 4,4´-diaminodiphenylmethane higher than permitted by legislation and five samples showed values of aniline above the limit. Considering the Mood test for polyamides, there were significant differences between the samples from Brazil and China, as well as between the colors in the silicone samples. Regarding the polyamides, the Chinese samples showed higher amounts of PAAs than the Brazilian ones, being above that allowed by legislation. Three Chinese silicone samples presented values above the legislation limit. These were all from the same importer.


Assuntos
Aminas/análise , Técnicas de Química Analítica/métodos , Cromatografia Líquida , Utensílios de Alimentação e Culinária/normas , Contaminação de Alimentos/análise , Espectrometria de Massas em Tandem , Compostos de Anilina/análise , Brasil , Carcinógenos/análise , China , Contaminação de Alimentos/prevenção & controle , Limite de Detecção , Nylons/química , Polipropilenos/química
15.
Artigo em Inglês | MEDLINE | ID: mdl-31100046

RESUMO

Braised chicken is a popular traditional chicken product in China with a special and complicated culinary method. However, there has been little research focused on the food safety problems caused by hazardous compounds in braised chicken. In this study, the contents of heterocyclic amines (HCAs) in representative braised chicken samples were determined. Total HCAs in braised chicken were relatively high (6.20-27.7 ng g-1), and aminoimidazoazaarenes (AIAs) took a large proportion (54.0-86.4%). 2-Amino-3-methylimidazo[4,5-f]quinoline (IQ) was found in all samples with a high level (2.72-13.5 ng g-1), whilst 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was low (0.14-0.41 ng g-1). 9H-pyrido[3,4-b]indole (Norharman) and 1-methyl-9H-pyrido[3,4-b]indole (Harman) were main components in aminocarbolines (ACs). So the potential safety risk in braised chicken caused by high HCAs content should be paid attention. Principal component analysis (PCA) was used to analyse and visualise the differences of HCAs levels among braised chicken samples. The result indicated that the differences among these samples were significant, but there were no obvious similarities between samples produced in the same regions. Moreover, there were rare significant positive correlations between chemical components (including moisture, fat, protein, creatine and free amino acids) and hazardous compounds. Considering PCA and correlation analysis results, these parameters may play a major role in the HCAs levels in Chinese traditional braised chicken.


Assuntos
Aminas/análise , Culinária/métodos , Compostos Heterocíclicos/análise , Carne/análise , Animais , Galinhas , China
16.
J Chromatogr A ; 1601: 310-318, 2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31054832

RESUMO

Efficient separation of aromatic amine isomers is a challenging issue in chemical industry and environmental analysis. Here we report the use of p-amino-tetradecyloxy-calix[4]arene (C4A-NH2) as a novel stationary phase for gas chromatographic (GC) separations. The statically coated C4A-NH2 capillary column showed a high column efficiency of 4332 plates/m for a 0.25 mm ID column and medium polarity. The C4A-NH2 stationary phase exhibited an excellent separation performance both for aromatic amine isomers and a complex mixture of aliphatic analytes with a wide ranging polarity, showing distinct advantages over the commercial polysiloxane stationary phases via diversified molecular interactions covering H-bonding, π-π, van der Waals interactions and shape-fitting selectivity. The retention mechanisms of aromatic amine isomers on C4A-NH2 column were further investigated by quantum chemistry calculations. In addition, the C4A-NH2 column showed good column repeatability with relative standard deviation (RSD) values of 0.03%-0.07% for run-to-run, 0.10%-0.27% for day-to-day and 2.6%-5.7% for column-to-column, respectively, and thermal stability up to 240℃.


Assuntos
Aminas/análise , Calixarenos/química , Fenóis/química , Aminas/química , Cromatografia Gasosa/métodos , Isomerismo , Reprodutibilidade dos Testes , Siloxanas/química
17.
Food Chem Toxicol ; 129: 138-143, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31034934

RESUMO

The aim of this study was to assess the inhibitory effects of Sonchus olearleu extract on the generation of heterocyclic amines in roasted pork patties cooked by pan-frying. All samples were cooked for two different durations (45 min and 105 min) under 200 °C and 230 °C. 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-ami- no-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinox-aline (4,8-DiMeIQx), harman, and norharman were detected and quantified. In patties cooked at 230 °C for 105 min, S. olearleu extract (0.5%) significantly inhibited the formation of IQ, harman, and norharman by 39%, 67%, and 63%, respectively. In contrast to IQ, the levels of harman and norharman were significantly reduced by the extracts tested. However, no such effects were observed for MeIQx and 4, 8-DiMeIQx. Notably, the inhibitory effect on heterocyclic amines is significantly correlated with the antioxidant potential and total phenolic content of S. olearleu extract.


Assuntos
Aminas/análise , Carcinógenos/toxicidade , Culinária , Compostos Heterocíclicos/análise , Produtos da Carne/análise , Extratos Vegetais/farmacologia , Sonchus/química , Animais , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Fluorescência/métodos , Suínos
18.
Talanta ; 198: 284-294, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30876562

RESUMO

Experiments were conducted to develop a method for the determination of a set of 17 military-relevant energetic compounds (including nitroaromatics, nitramines, and nitrate esters) in 5 types of marine tissues (Dungeness crab, Manila clam, starry flounder, sea cucumber, and geoduck) using reversed-phase high performance liquid chromatography with a UV detector (RP-HPLC-UV). Dry-ice grinding was evaluated and found to be an excellent method of sample homogenization prior to sample extraction and determination. An extract cleanup procedure based on solid-phase extraction was assessed. A cleanup procedure using solid phase extraction was adequate for the removal of interferences prior to HPLC analysis for the five marine tissue matrices tested. Mean method detection limits (MDLs) were estimated using two columns at two wavelengths (254 and 210 nm) and ranged from 17 to 293 µg/kg for the five tissue matrices tested. A six-laboratory intercomparison test was conducted to evaluate the performance of the method, each analyzing five marine tissue matrices fortified at three levels. The same marine tissues were used in the laboratory intercomparison study except Pacific halibut was substituted for starry flounder. Overall, USEPA Method 8330B modified for tissue analysis showed suitable detection capability, analytical accuracy, precision, sensitivity, linear range, and robustness for sixteen (16) of the seventeen (17) analytes, for all five (5) of the marine tissue matrices studied. The exception was tetryl that proved to be unstable for all matrices as has been found for soils and sediments.


Assuntos
Aminas/análise , Ésteres/análise , Nitratos/análise , Nitrobenzenos/análise , Animais , Bivalves , Braquiúros , Cromatografia Líquida de Alta Pressão , Linguado , Pepinos-do-Mar , Espectrofotometria Ultravioleta
19.
Bioresour Technol ; 282: 447-455, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30889536

RESUMO

Methods for assessing odors in municipal sewage sludge aerobic composting plants (MSSACPs) have been ineffective. This study identified the emission amount of typical odor-producing compounds, including NH3 and volatile sulfide compounds from a full-scale MSSACP, and evaluated risks of odor emissions based on odor intensity and odor active value. Results revealed all sampling sites (i.e. sludge stacking yard, composting workshop, and screening workshop) produced serious odors, especially in the composting workshop. In the composting workshop, the amounts of DMDS (174.59 µg·dry kg-1) and DMS (71.64 µg·dry kg-1) emitted were far lower than that of NH3 (6062.56 µg·dry kg-1). However, DMDS and DMS showed a similar intensity as NH3 according to odor intensity assessment. Furthermore, both of their odor active values were higher than that of NH3. Using results from both odor intensity and odor active value were more reliable for the assessment of odors from MSSACPs.


Assuntos
Aminas/análise , Compostagem , Odorantes/análise , Esgotos , Sulfetos/análise
20.
J Chromatogr A ; 1597: 109-118, 2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-30910385

RESUMO

An azo coupling-based derivatization method is reported for high-sensitivity liquid chromatography-tandem mass spectrometry (LC-MS/MS) quantitation of tetrahydrocannabinol (THC) and other aromatic compounds, i.e. phenols and amines. Through the azo coupling of a diazonium to an analyte, it produces a derivatized analyte which has enhanced ionization efficiency and results in high-response fragments in tandem mass spectrometry. The derivatization method was applied to six typical aromatic compounds using three different diazonium salts as derivatization reagents, demonstrating its applicability to a variety of analytes and reagents. The derivatization reaction can be directly carried out in neat samples, and after derivatization the samples can be immediately sent to the LC-MS/MS instrument for analysis. These advantages facilitate a one-step sample preparation procedure that can be completed in less than one hour, allowing for a "derivatize & shoot" lab workflow. The derivatization method was applied to establish an LC-MS/MS assay for the quantitation of THC in human breath samples. The derivatization conditions were studied in this application, including the effects of acidity, organic solvent, and diazonium concentration in the reaction. The THC derivatization assay was validated and achieved a limit of quantitation (LOQ) of 0.50 pg/ml using either of the two regio-isomers of the azo-derivative of THC (THC-DRV). To prove that the derivatization method has compatibility with complex-matrix samples, a THC derivatization assay for serum samples was established, in which the azo coupling reaction was directly carried out in crude protein-precipitated supernatants. An LOQ of 5.0 pg/ml was achieved. In addition, excellent correlation between THC derivatization and non-derivatization assays was found in the analysis of whole blood samples.


Assuntos
Testes Respiratórios/métodos , Cromatografia Líquida , Dronabinol/análise , Espectrometria de Massas em Tandem , Aminas/análise , Análise Química do Sangue , Dronabinol/sangue , Humanos , Indicadores e Reagentes , Limite de Detecção , Fenóis/análise
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