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1.
Environ Monit Assess ; 192(11): 705, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33063182

RESUMO

The present study aimed at evaluating the levels of microbiological contamination, total petroleum hydrocarbons (TPHs), and heavy metals (As, Cd, Hg, and Pb) in the edible tissues of commonly consumed fish (8 species) collected from the marine area of Tripoli, Northern Lebanon. Total coliform levels in all sampled fish, and Escherichia coli levels in Liza ramada only, exceeded the permissible limits set by FAO/WHO 2002. Staphylococcus aureus counts were within the recommended thresholds, while sulfate-reducing bacteria levels were the highest in fish of the genus Liza. Salmonella species and Listeria monocytogenes were not detected in all fish analyzed. Analysis of heavy metals levels showed that arsenic exhibited the highest levels among the assessed metals in all genera. Levels of As in Epinephelus, Diplodus, Oblada, and Liza were above the acceptable limits, while Cd levels were below the permissible limits set by the European Commission. Significant negative correlation was found between levels of As and Hg in muscle tissues and fish size (length). Levels of TPHs were the highest in fish of the genus Epinephelus. Significant difference in TPHs contamination was found within three fish genera, with Epinephelus being the most contaminated.


Assuntos
Metais Pesados , Petróleo , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Contaminação de Alimentos/análise , Hidrocarbonetos , Líbano , Metais Pesados/análise , Poluentes Químicos da Água/análise
2.
Wei Sheng Yan Jiu ; 49(5): 755-758, 2020 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-33070819

RESUMO

OBJECTIVE: To investigate the level of lead in cereals and related products from Zhejiang market, and to provide the preliminary assessment. METHODS: Lead was detected in 4855 samples of cereals and related products during 2014-2019, food consumption data was taken from Zhejiang residents' consumption survey in 2015-2016. RESULTS: The total detection rate of lead in cereals and related products was 59. 03%, and the acceptance rate was 99. 3% when compared to the national food safety standards(GB 2762-2017). The average lead level in cereals and related products was 0. 031 mg/kg, high mean level was found in millet with 0. 049 mg/kg, low mean level was in grain cans with 0. 020 mg/kg. The average dietary exposure to lead via cereals and related products was 0. 16 µg/(kg·d), and 0. 45 µg/(kg·d) for high consumer(P97. 5). CONCLUSION: Lead in cereals and related products are at very low contamination levels, residents' average daily intake of lead from grains and products was low in Zhejiang Province, but measures are still needed to reduce lead in cereal products considering the adverse health effects of lead.


Assuntos
Grão Comestível , Chumbo , Exposição Dietética , Grão Comestível/química , Contaminação de Alimentos/análise , Inocuidade dos Alimentos , Chumbo/análise
3.
Wei Sheng Yan Jiu ; 49(5): 759-794, 2020 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-33070820

RESUMO

OBJECTIVE: To investigate the contamination of benzo(a)pyrene in edible vegetable oil from Henan Province. METHODS: A total of 1190 edible vegetable oil samples from Henan Province were collected. The concentration of benzo(a)pyrene was examined by high performance liquid chromatography. RESULTS: The concentration of benzo(a)pyrene in prepackaged edible vegetable oils was <0. 3-63. 5 µg/kg with an average of 1. 5 µg/kg. The detection rate of benzo(a)pyrene in samples was 80. 0%, and the over standard rate was 0. 6%. In terms of subclasses of vegetable oil, the sesame seed oil samples were most seriously contaminated with benzo(a)pyrene. The risk of the benzo(a)pyrene contamination of sesame seed oil produced by aqueous extraction method was higher than that by mechanical pressed method. The risk of benzo(a)pyrene contamination in sesame seed oil and rapeseed oil increased as the decrease of quality grade. CONCLUSION: The result suggested that the sesame seed oil produced by aqueous extraction method had high risk in benzo(a)pyrene contamination in Henan Province.


Assuntos
Benzo(a)pireno , Verduras , Cromatografia Líquida de Alta Pressão , Contaminação de Alimentos/análise , Óleos Vegetais
4.
Wei Sheng Yan Jiu ; 49(5): 829-867, 2020 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-33070831

RESUMO

OBJECTIVE: To establish an analytical method for determination of 20 kinds of ß-receptor blockers residues in animal foods by ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). METHODS: The samples of animal foods were enzymatic hydrolysis by trichloroacetic acid(TCA), purified by MCX column. The separation was performed on a Waters ACQUITYTM BEH C_(18 )column(100 mm×2. 1 mm, 1. 7 µm), then the target compounds were detected by UPLC-MS/MS with ESI positive ion scan in mode of multiple reaction monitoring(MRM) and quantified by matrix matched external standard method. RESULTS: At the spiked level of 1, 2 and 4 µg/kg, the recoveries of each compound were in the range of 61. 9%-119. 1% with the relative standard deviations of 1. 5%-28. 4%(n=6). The qualitative limits of detections were 0. 01-0. 15 µg/kg and the quantitative limits were 0. 03-0. 50 µg/kg for the 20 targets compounds. By using the established method, the target compounds in 30 animal foods were detected, and no excessive veterinary drug residue were detected. CONCLUSION: The established method is simple, rapid, high sensitivity and good stability, with a wide variety and a certain development. It can provide more convenient and fast detection method support for the daily monitoring of veterinary drug residues in animal foods.


Assuntos
Contaminação de Alimentos , Espectrometria de Massas em Tandem , Ração Animal , Animais , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Contaminação de Alimentos/análise
5.
Wei Sheng Yan Jiu ; 49(5): 836-839, 2020 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-33070832

RESUMO

OBJECTIVE: To evaluate dietary exposure of cadmium and their potential health risks of adults in Jiangxi Province. METHODS: The concentration data of cadmium of 11 kinds of foods were obtained from food safety monitoring in Jiangxi Province in 2012-2017. The food consumption data was obtained from food consumption survey in Jiangxi Province in 2016. Based on the deterministic assessment model, the dietary exposure of cadmium of adults in Jiangxi Province was calculated. RESULTS: The average dietary exposure of cadmium was 18. 426 µg/kg per month, accounting for 73. 7% of the provisional tolerable monthly intake(PTMI). The large portion exposure(P95) of cadmium was 29. 724 µg/kg per month, accounting for 118. 9% of PTMI. The average and the large portion(P95) dietary exposure range of cadmium in different age groups were 16. 224-19. 774 and 24. 059-33. 387 µg/kg per month, respectively. It was indicated that the main dietary sources of cadmium were rice and vegetables, which were contributed more than 92% of total dietary exposure of cadmium. CONCLUSION: The potential health risks caused by dietary exposure to cadmium of adults in Jiangxi Province was at an acceptable level. But there were some potential health risks in high exposure population.


Assuntos
Cádmio , Exposição Dietética , Cádmio/análise , Cádmio/toxicidade , Dieta , Contaminação de Alimentos/análise , Verduras
6.
Wei Sheng Yan Jiu ; 49(5): 840-872, 2020 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-33070833

RESUMO

OBJECTIVE: To analyze the zearalenone(ZEN) level in coix seed, and assess the risk of dietary exposure of ZEN in coix seed in Shanghai. METHODS: The ZEN contents of 147 coix seed samples collected in Shanghai were determined. The consumption data of 730 adults in Shanghai was collected by questionnaire survey with random sampling method. Dietary intake of ZEN from coix seed in Shanghai was simulated by Monte Carlo simulation. RESULTS: The total detection rate of ZEN in coix seed was 69. 39 %(102/147), with the content range of <1. 0-9361 µg/kg and the average value of 327. 7 µg/kg. The average exposure level of populations to ZEN in coix seed was 0. 0216 µg/(kg·d), which was much lower than the tolerable daily intake(TDI). The high exposure level(P95) of populations to ZEN in coix seed was 0. 0609 µg/(kg·d), which accounted for about 24% of TDI. There were about 1. 1% people with the dietary exposure to ZEN exceeding TDI on the basis of the ZEN contents in coix seed and consumption data of coix seed in Shanghai. CONCLUSION: The health risk of ZEN exposure of coix seed in Shanghai population is lower when taking coix seed regularly, and there are potential health risks when taking coix seed highly contaminated with ZEN at a higher dose for a long time.


Assuntos
Coix , Zearalenona , China , Exposição Dietética , Contaminação de Alimentos/análise , Sementes/química , Zearalenona/análise , Zearalenona/toxicidade
7.
Environ Monit Assess ; 192(11): 692, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-33037524

RESUMO

Residue levels of seven commonly used pesticides were determined in random samples of tomatoes, French beans, and kale collected from horticultural farms in Buuri, Imenti North, and Imenti South sub-counties in Meru, Kenya, just before delivery to the consumers. QuEChERS method for extraction followed by LC-MS/MS was used to determine the concentrations. The concentrations (µg kg-1 wet weight) in French beans, kale, and tomatoes ranged from below detection limit (BDL): BDL-48.65 (carbendazim), BDL-290.76 (imidacloprid), BDL-2.81 (acetamiprid), BDL-25.76 (azoxystrobin), BDL-105.18 (metalaxyl), BDL-0.15 (diazinon), and BDL-0.17(chlorpyrifos). The maximum residue levels determined in the horticultural produce from the three regions were 290 µg kg-1 for imidacloprid in tomatoes from Buuri and 25.76 µg kg-1for azoxystrobin in French beans from Imenti South. The pesticide residue levels generally were extremely low and met the MRLs set by EU and other countries, except for carbendazim and metalaxyl in French beans, and posed no concern to human health. The estimated daily intakes (EDI) (mg kg-1 BW/day) for the population of Meru County were very low ranging from 1.685 × 10-8 (acetamiprid) to 2.381 × 10-5 (imidacloprid) in tomatoes, 2.849 × 10-9 (metalaxyl) to 3.633 × 10-7 (azoxystrobin) in French beans, and 1.392 × 10-8 (diazinon) in kale, respectively. The health risk indices were subsequently extremely low for the detectable pesticide residues, ranging from 6.74 × 10-7 (acetamiprid) to 3.97 × 10-4 (imidacloprid) in tomatoes, 3.56 × 10-8 (metalaxyl) to 5.52 × 10-5 (chlorpyrifos) in French beans, and 6.96 × 10-5 (diazinon) in kale, respectively, indicating no health risk in the population, but their presence in these vegetables cannot be ignored as long-term exposure can still cause health risks.


Assuntos
Brassica , Lycopersicon esculentum , Resíduos de Praguicidas , Praguicidas , Cromatografia Líquida , Monitoramento Ambiental , Contaminação de Alimentos/análise , Humanos , Quênia , Resíduos de Praguicidas/análise , Praguicidas/análise , Espectrometria de Massas em Tandem
8.
Wei Sheng Yan Jiu ; 49(4): 591-602, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32928350

RESUMO

OBJECTIVE: To establish an analytical method for determination of 6 kinds of α_2-agonists in animal foods by ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). METHODS: The samples of animal food were enzymatic hydrolysis by ß-glucosidase/arylsulfatase, purified by MCX column. The separation was performed on a Dikma leapsil C_(18) column(2. 1 mm×100 mm, 2. 7 µm), then the target compound were detected by ultra high performance liquid chromatography-tandem mass spectrometry with electron spray ionization(ESI) positive ion scan in mode of multiple reaction monitoring(MRM) and quantified by matrix matched external standard method. RESULTS: At the spiked level of 1, 2 and 4 µg/kg, the recoveries of each compound were in the range of 70. 4%-111. 2% with the relative standard deviations of 2. 3%-18. 8%. The qualitative limits of detections were 0. 06-0. 3 µg/kg and the quantitative limits were 0. 2-1. 0 µg/kg for the 6 targets compounds. By using the established method, the target compound in 30 samples including pork, pig liver, pig kidney, beef and mutton were detected, and no excessive veterinary drug residue were detected. CONCLUSION: The established method is simple, rapid, high sensitivity and good stability, with a wide variety and a certain development. It can provide more convenient and fast detection method support for the daily monitoring of veterinary drug residues in animal food.


Assuntos
Resíduos de Drogas/análise , Espectrometria de Massas em Tandem , Animais , Bovinos , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Contaminação de Alimentos/análise , Suínos
9.
Wei Sheng Yan Jiu ; 49(4): 608-612, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32928356

RESUMO

OBJECTIVE: To understand the contamination status of Staphylococcus aureus in food and processing. METHODS: From July 2017 to January 2018, raw/cooked meat products, aquatic products, soybean products and other foods for sale were collected from five districts and counties of Chengdu, and some processing samples were collected from school cantons, farms and slaughterhouses of Chengdu. Staphylococcus aureus in food and processing in Chengdu was detected by plate method and PCR method, staphylococcus aureus enterotoxin was determined by enzyme-linked fluorescence immunoassay, and Risk Ranger software was used for semi-quantitative Risk assessment. RESULTS: A total of 429 samples were collected from food and processing in Chengdu. 78 strains(18. 2%) of Staphylococcus aureus were detected by plate method, among which 76 strains were identified as Staphylococcus aureus by PCR. The highest detection rate was found in raw meat(34. 1%), and the highest detection rate was found in raw chicken(54. 2%). The detection rate of Staphylococcus aureus in samples from farmers' markets(34. 0%) was higher than that of supermarkets(28. 3%). Eighteen of the 78 strains produced enterotoxin, raw chicken and duck meat from supermarkets(9) and farmers' markets(6), and hand smears by school cafeteria workers(2). According to the risk score, the food safety risks are in descending order from raw meat products(55 points), soybean products(50 points), cooked meat products(43 points) and aquatic products(43 points). CONCLUSION: Raw meat and soybean products are high risk foods contaminated by S. aureus, cooked meat and aquatic products are medium risk foods.


Assuntos
Infecções Estafilocócicas , Staphylococcus aureus , Animais , Enterotoxinas , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Humanos , Carne
11.
J Chromatogr A ; 1626: 461379, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797854

RESUMO

Ordered porous materials are attracting enormous attention due to their uniform pore structures, particularly the magnetic photonic crystal microspheres (PCMs) which not only possess unique photonic crystal structure but also can achieve separation easily based on magnet. Here, a two-phase microfluidic self-assembly synthetic system was established simply and employed for the preparation of three dimensional PCMs (3DPCMs) by using the emulsion droplet approach. One phase (dispersed phase) was an aqueous emulsion containing Fe3O4, silica (SiO2) and polystyrene (PS) nanoparticles; another phase (continuous phase) was pure silicone oil. The droplets were formed by introducing the dispersed phase into the continuous phase through a tee valve. By heating the droplets, the water would evaporate and the nanoparticles would finally assemble into solid microspheres, which could be changed into macroporous 3DPCMs after removal of the PS nanoparticles by calcination. The contents and particle sizes of Fe3O4, SiO2 and PS nanoparticles in the dispersed phase were investigated in detail and optimized to prepare macroporous magnetic 3DPCMs with high quality. The morphologies, surface crystal structure, magnetic property, particle size distribution, specific surface area and pore size of the macroporous magnetic 3DPCMs were characterized. The expected 3DPCM displayed regular and uniform photonic crystal structure, narrow particle size distribution and strong magnetic property. The macroporous magnetic 3DPCMs grafted with vomitoxin (DON)-antibodies could be applied for selective enrichment of DON in real samples.


Assuntos
Magnetismo , Microfluídica/métodos , Microesferas , Tricotecenos/análise , Anticorpos/imunologia , Cromatografia Líquida de Alta Pressão , Óxido Ferroso-Férrico/química , Contaminação de Alimentos/análise , Nanopartículas/química , Tamanho da Partícula , Poliestirenos/química , Porosidade , Dióxido de Silício/química , Espectrofotometria , Tricotecenos/imunologia
12.
Sci Total Environ ; 746: 141098, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32763602

RESUMO

Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) are still considered among the most important groups of contaminants in the food chain. Self-control by food producers and official control by authorities are important activities that allow contaminant sources to be traced and promote further reduction in food and feed levels. Strict but feasible maximum levels were set by the EU Commission for food and feed to support this strategy, as well as action levels and thresholds. When products exceed these levels, it is important to trace the source of contamination and take measures to remove it. Congener patterns of PCDD/Fs and PCBs differ between sources and are important tools for source identification. Therefore, patterns associated with different sources and incidents relating to various feed matrices and certain agricultural chemicals were collated from published scientific papers, with additional ones available from some laboratories. The collection was evaluated for completeness by presentations at workshops and conferences. Primary sources appear to derive from 5 categories, i) by-products from production of organochlorine chemicals (e.g. PCBs, chlorophenols, chlorinated pesticides, polyvinyl chloride (PVC)), ii) the result of combustion of certain materials and accidental fires, iii) the use of inorganic chlorine, iv) recycling/production of certain minerals, and v) certain naturally occurring clays (ball clay, kaolinite). A decision tree was developed to assist in the identification of the source.


Assuntos
Benzofuranos/análise , Dioxinas/análise , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análise , Dibenzofuranos , Dibenzofuranos Policlorados , Cadeia Alimentar , Contaminação de Alimentos/análise
13.
J Water Health ; 18(4): 574-578, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32833683

RESUMO

Giardia and Cryptosporidium are recognized as leading causes of waterborne and foodborne diarrhoeal disease with worldwide distribution. The study aimed to determine the protozoan contamination of various foods of plant origin. A total of 72 samples from 27 different varieties of fresh vegetables and fruits were collected from supermarkets and open markets in North-Western Greece and were examined using conventional diagnostic methods. Two out of 72 (2.8%) samples were found positive for Cryptosporidium oocysts, while no sample was found to be positive for Giardia cysts. The results show the presence of protozoan contamination in foods of plant origin, which may constitute a potential health hazard.


Assuntos
Cryptosporidium , Contaminação de Alimentos/análise , Giardia , Animais , Criptosporidiose , Análise de Alimentos , Giardíase , Grécia , Oocistos
14.
PLoS One ; 15(8): e0236871, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32745115

RESUMO

Element bioaccessibility consists of the fraction of the element that is mobilized from food matrices into digestive extractants. The degree of bioaccessibility of a toxic metal is a fundamental consideration in estimating its bioavailability. In addition, gaining a better understanding of the essential elements released into the gastro intestinal fluids allows a more thorough assessment of the health benefits of food matrices in the field of nutrition science. In the present study, an in vitro digestion model simulating gastro-intestinal digestion (GID) was used to investigate the bioaccessibility of stable elements in mixed leaf salad and 210Po in various foods (meat, seafood, vegetables). The simulation was carried out over three phases: after a pre-treatment with a saliva solution, raw and cooked seafood samples were subjected to a complete simulated gastrointestinal digestion (gastric digestion followed by bile-pancreas digestion). The 210Po bioaccessibility was found to range from 16.2±9.39% to 62.8±17.7% and from 6.26±2.15% to 67.5±13.1% for raw and cooked food respectively. Moreover, bioaccessibility could not be determined for As, Cd, Ce, Co, Cr, Hg, La, Pb, Sb, Sn, Te, Th, Tl, Ti, U. It proved to be poor (1-16%) for Al, Fe and S; fair (40-50%) for Cu, P, and Si; and high (>50%) for Ba, Ca, K, Mg, Mn, Ni, Rb, Sr, Zn. The results show that bioaccessibility varies according to the chemical form of the element in the food as well as the matrix composition.


Assuntos
Disponibilidade Biológica , Contaminação de Alimentos/análise , Polônio/análise , Oligoelementos/análise , Digestão , Humanos , Técnicas In Vitro/métodos , Carne/análise , Alimentos Marinhos/análise , Verduras/química
15.
J Chromatogr A ; 1627: 461399, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823104

RESUMO

Citrinin is a toxic small organic molecule produced as a secondary metabolite by fungi types Penicillium, Monascus and Aspergillus and is known to contaminate various food commodities during postharvest stages of food production. During the last 10 years, most reported methods for citrinin analysis employed enzyme-linked immunosorbent assays or high-performance liquid chromatography. Over this same time period, liquid extraction, solid-phase extraction, dispersive liquid-liquid microextraction and QuEChERS were the most cited sample preparation and clean-up methods. In this review the advantages and disadvantages of the various sample preparation, separation and detection methods for citrinin analysis over the last decade are evaluated. Furthermore, current trends, emerging technologies and the future prospects of these methods are discussed.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Citrinina/análise , Espectrometria de Massas em Tandem/métodos , Aspergillus/metabolismo , Citrinina/isolamento & purificação , Citrinina/urina , Ensaio de Imunoadsorção Enzimática , Contaminação de Alimentos/análise , Humanos , Microextração em Fase Líquida , Monascus/metabolismo , Extração em Fase Sólida
16.
Mar Pollut Bull ; 159: 111512, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32777545

RESUMO

Swordfish is a widely consumed fish worldwide. The aim of this work was to evaluate levels of As, Zn, Mn, Fe, Cu, Al, Cr, Ni, Se, Cd, Pd and Hg in 28 samples of swordfish muscles, coming from zone of Food and Agriculture Organization (FAO) namely 37.1 and 37.2, in order to assess potential public health risks. 100% of the samples had Cd levels not detectable, 32.14% of samples exceeded European maximum limits set for Hg. Health risk assessment showed a not dangerous condition for Al (0.65% of Tolerable Weekly Intake), Ni (0.27% of Tolerable Daily Intake) and Pb (0.68% of Provisional Tolerable Weekly Intake), but very hazardous states for Hg (159.69% of Tolerable Weekly Intake) and As (1099.45% for minimum value of Benchmark Dose Limit). Target Hazard Quotient (THQ) showed dangerous values only for As and Hg. Analytical data of the present study suggest a swordfish prudent consumption.


Assuntos
Contaminação de Alimentos/análise , Mercúrio/análise , Animais , Peixes , Humanos , Mar Mediterrâneo , Medição de Risco , Alimentos Marinhos/análise
17.
PLoS One ; 15(7): e0235345, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32667930

RESUMO

This study was carried out to investigate the risks of simultaneous exposure to pesticide residues and bacteria contaminants in locally produced fresh vegetables and vegetables in Tanzania. A total of 613 samples were analyzed for pesticide residues, out of which 250 were also analyzed for bacterial contamination. Overall, 47.5% had pesticide residues, 74.2% exceeded Maximum Residue Levels (MRLs). Organophosphorus (95.2%), organochlorines (24.0%), pyrethroids (17.3%), and carbamates (9.2%) residues dominated. MRL values were mostly exceeded in tomatoes, onions, watermelons, cucumbers, Chinese cabbage, and sweet paper. Tetramethrin (0.0329-1.3733 mg/kg), pirimiphos-methyl (0.0003-1.4093 mg/kg), permethrin (0.0009-2.4537 mg/kg), endosulfan (beta) (0.0008-2.3416 mg/kg), carbaryl (0.0215-1.5068 mg/kg), profenofos (0.0176-2.1377 mg/kg), chlorpyrifos (0.0004-1.2549 mg/kg) and dieldrin (0.0011-0.5271 mg/kg) exceeded MRLs. The prevalence of bacteria contamination was high (63.2%). Enterobacter (55.6%) Pseudomonas aeruginosa (32.4%), E. coli (28.2%), Citrobacter (26.8%), Klebsiella oxytoca (14.8%), and Salmonella (7.7%) were isolated. Furthermore, 46.4% tested positive for both pesticide residues and bacterial contaminants. Vegetables from farms (60.7%) contained more dual contaminants than market-based vegetables (41.8%). This may have resulted from excessive pesticide use and unhygienic handling of fresh fruits and vegetables at production level. Binary logistic regression showed that fresh fruits and vegetables with pesticide residues were 2.231 times more likely to have bacteria contaminants (OR: 2.231; 95% CI: 0.501, 8.802). The contamination levels of pesticide residues and bacterial contaminants could be perceived as a serious problem as most fresh fruits and vegetables recorded values of pesticide residues far above the MRLs with pathogenic bacteria isolated in higher proportions. MRLs was higher in most vegetables consumed raw or semi-cooked such as watermelons, carrots, cucumber, tomatoes, onion and sweet paper. There is an urgent need to develop pesticide monitoring and surveillance systems at farmer level, educating farmers and promoting the use of greener pesticides to mitigate the health effects of pesticides and bacterial contaminants.


Assuntos
Contaminação de Alimentos/análise , Frutas/efeitos adversos , Praguicidas/efeitos adversos , Verduras/efeitos adversos , Citrobacter/isolamento & purificação , Citrobacter/patogenicidade , Enterobacter/isolamento & purificação , Enterobacter/patogenicidade , Frutas/química , Frutas/microbiologia , Humanos , Hidrocarbonetos Clorados/efeitos adversos , Hidrocarbonetos Clorados/química , Klebsiella oxytoca/isolamento & purificação , Klebsiella oxytoca/patogenicidade , Resíduos de Praguicidas/efeitos adversos , Resíduos de Praguicidas/química , Praguicidas/química , Pseudomonas aeruginosa/isolamento & purificação , Pseudomonas aeruginosa/patogenicidade , Piretrinas/efeitos adversos , Piretrinas/química , Salmonella/isolamento & purificação , Salmonella/patogenicidade , Verduras/química , Verduras/microbiologia
18.
J Chromatogr A ; 1625: 461275, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709327

RESUMO

Efficient extraction of polar sulfonamides antibiotics from aqueous samples and food is very challenging, because they are hydrophilic, their concentration is very low, and the matrix is complex. Covalent organic frameworks (COFs), a novel porous organic material, have attracted great attention. In this work, the spherical triphenylbenzene-dimethoxyterephthaldehyde-COFs (TPB-DMTP-COFs) were synthesized by a simple room temperature method, and due to their attractive properties, such as high outstanding acid-base stability, large specific surface area, low skeletal density, inherent porosity and high crystallinity, so TPB-DMTP-COFs as ideal solid phase extraction adsorbents showed excellent adsorption performance for trace polar sulfonamides in food and water. TPB-DMTP-COFs were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, powder X-ray diffraction, and so on. The important parameters were optimized to improve the extraction efficiency of TPB-DMTP-COFs toward sulfonamides. Analysis of sulfonamides was performed by liquid chromatography-tandem mass spectrometry. The developed method based on TPB-DMTP-COFs material achieved low limits of detection (0.5-1.0 ng L-1), wide linearity (5-1000 ng L-1), and good repeatability (2.5%-8.7%). The possible extraction mechanism was also discussed. Finally, the method was successfully applied to the enrichment and detection of sulfonamides in environmental water samples and food samples. The present study indicated that TPB-DMTP-COFs had splendid prospects in highly sensitive analysis of other pollutants in complex matrix.


Assuntos
Análise de Alimentos , Estruturas Metalorgânicas/química , Extração em Fase Sólida/métodos , Sulfonamidas/análise , Espectrometria de Massas em Tandem/métodos , Poluentes Químicos da Água/análise , Adsorção , Animais , Cromatografia Líquida , Contaminação de Alimentos/análise , Leite/química , Carne de Porco/análise , Porosidade , Sulfonamidas/química , Água/química
19.
Environ Monit Assess ; 192(8): 519, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32671553

RESUMO

Despite increased public health concerns on the occurrences of potentially pathogenic/mycotoxigenic fungi in public drinking water system, dissemination of hygienically relevant fungi and their associated mycotoxins via distribution system under the dual burden of ageing infrastructure and ancillary distribution network lacking infrastructure for high-pressure water delivery systems is unknown. In this study, the diversity of fungi and occurrence of mycotoxins at 30 different points along treated piped water supply and ancillary distribution networks in Johannesburg, South Africa, were monitored for 12 months. Mycological analysis using cultural and molecular methods yielded 282 fungi belonging to phylum Ascomycota, having Aspergillus (91%), Penicillium (65%) and Trichoderma (31%) as dominant genera, with Aspergillus fumigatus, Penicillium citrinum, Purpureocillium lilacinum and Aspergillus flavus as the most prevalent species. Communal standpipe and reservoir outlets had significantly higher prevalence than other water samples. There was no strong correlation between total coliforms (r = 0.4266) and residual chlorine (r = - 0.1937), and fungal prevalence at p < 0.05. LC-MS/MS analysis detected aflatoxins B1, M1, G1 and G2 in 50, 9, 9 and 46% of water samples analysed, respectively, ranging between 0 and 3.18 ng/l. Deoxynivalenol (DON), 3-acetyl DON and 15-acetyl DON levels were between 8.4-96.1, 18.7-145.7 and 15.2-71.6 ng/l, respectively. However, the estimated average daily dose (ADD) for detected mycotoxins was below the tolerable daily intake (TDI), suggesting no toxicological risk. Presence of potentially mycotoxigenic fungi, despite the low toxicological risk, demonstrates a need for appropriate monitoring for fungi and mycotoxins in treated drinking water distribution systems for improved water quality and long-term public health assurance.


Assuntos
Água Potável , Micotoxinas/análise , Cromatografia Líquida , Monitoramento Ambiental , Contaminação de Alimentos/análise , Fungos , Saúde Pública , África do Sul , Espectrometria de Massas em Tandem , Qualidade da Água
20.
Wei Sheng Yan Jiu ; 49(3): 397-402, 2020 May.
Artigo em Chinês | MEDLINE | ID: mdl-32693887

RESUMO

OBJECTIVE: To study the residue levels of acaricides in Chinese dietary samples and dietary intakes of Chinese residents. METHODS: A total of 288 mixed dietary samples from 24 provinces in the 6 th Chinese total diet study were analyzed for residue levels of acaricides by liquid chromatography-high resolution mass spectrometry. Additionally, based on the dietary consumption of local residents, the dietary intake of acaricides was estimated. RESULTS: Among the tested dietary samples, the detection rates of pyridaben, spirodiclofen and propargite were 11. 8%(34/288), 8. 7%(25/288), and 6. 3%(18/288), respectively. They were mainly detected in vegetable and fruit samples. The average residue level of pyridaben in the vegetable samples was higher than that in other dietary samples with the content of 6. 26 µg/kg. The average residue level of spirodiclofen in the fruits samples was higher than that in other dietary samples with the content of 3. 92 µg/kg. The average residue level of propargite in the vegetable samples was higher than that in other dietary samples with the content of 0. 90 µg/kg. According to the dietary exposure analysis, the average dietary exposure levels of pyridaben, spirodiclofen and propargite in the general population of China were 48. 31, 1. 62 and 2. 25 ng/(kg·d), respectively. According to the dietary contribution rate, the three acaricides were mainly from vegetable samples. CONCLUSION: Although acaricides were detected in varying degrees in the Chinese dietary samples, the general population's health risk caused by the dietary intake in China is at a low level.


Assuntos
Acaricidas , Exposição Dietética , China , Dieta , Contaminação de Alimentos/análise , Humanos , Verduras
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