首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Pinot noir, bastardo, rkaziteli and semillon grapes on vines grown in the Barossa Valley of South Australia were treated with a commercial dithianon formulation. The grapes were harvested by hand eight days later, and made into wine. Grab samples of berries, grape juice and the young wine were analysed for fungicide residues. No dithianon was detected in control grape samples, grape juices or wines. Significant dithianon levels were detected on the skins of treated grape samples. Dithianon is stable on the surface of grapes under the ambient conditions prevalent under the grape canopy for at least two weeks. No dithianon was detected in grape juice, on grape skins after berry crushing, in the lees, or in the young wine. Dithianon is unstable in grape juice and wine. Dithianon half‐life (initial concentration = 1 μg/mL) in semillon grape juice = 2.8 h, semillon wine = 0.58 h, pinot noir grape juice = 4.6 h, and pinot‐noir wine = 0.29 h. Treatment with fining agents or heat does not significantly reduce the rate of degradation. These results suggest that spraying table grapes with dithianon two weeks before harvest would result in exposure to essentially the full dose of active ingredient sprayed, and increase the risk to human health through ingestion of this compound. However, any threat to human health from ingestion through grape juice or wine is limited since any contact with grape juice or wine leads to rapid decomposition of dithianon by some as yet undetermined process.  相似文献   

2.
农药施用于田间,必然会残留于环境中。农药残留的分析方法多种多样。为探究灵敏度高、重现性好的样品前处理方法,建立了超声辅助乳化液相微萃取,结合气相色谱和火焰光度检测器测定绿茶饮料和番茄汁中5种有机磷农药的方法,对萃取条件进行了优化,如萃取溶剂种类和体积、超声频率和时间、盐效应。在优化后的萃取条件下,5种有机磷农药实现良好分离,空白添加实验结果表明在0.1~10μg·L-1之间,线性相关系数在0.9985~0.9994之间,检测限在0.005~0.020μg·L-1之间,相对标准偏差(n=5)在4.3%~9.4%之间。在绿茶饮料和番茄汁实际样本检测中,目标分析物含量均低于检出限。样本添加回收试验的回收率均大于88.5%,相对标准偏差(n=3)在2.2%~9.8%之间,结果表明该方法用于液体样本中农药残留检测真实可靠。  相似文献   

3.
为摸清稻菜轮作土壤中农药(CUPs)残留特征与生态风险,采集海南岛南渡江流域稻菜轮作系统168个土壤样品,利用Qu ECh ERS-超高效液相色谱-串联质谱(UPLC-MS/MS)检测土壤中25种CUPs残留水平,结合土壤因子与作物类型分析CUPs残留关键影响因素,以风险熵法评估其生态风险。结果表明,∑25 CUPs处于0.30μg·kg-1—11.625 mg·kg-1之间,吡虫啉、多菌灵检出率与质量分数最高;∑25CUPs呈现辣椒(Capsicumannuum L.)>大白菜(Brassicapekinensis L.)>豆角(Vigna unguiculata L.)>线瓜(Luffaacutangula L.)>水稻(Oryza sativa L.)>未种植趋势,CUPs残留种类与含量随作物类型显著不同。主成分分析显示,多菌灵、吡虫啉为主要杀菌剂与杀虫剂种类;冗余分析结果显示有机质、黑炭与其中多菌灵、甲基硫菌灵正相关,而土壤总氮、总磷、p H与CUPs残留量与种类相关性不高。从单一和联合风险熵(RQ)看,多菌灵、吡虫啉与甲基硫菌灵呈高生态风险,其高风险作物种类、采样期和区域为辣椒、7月及中游区域,而其他CUPs的RQ均小于1,无高生态风险。土壤中总CUPs、杀菌剂与杀虫剂的RQ均大于1,CUPs多残留生态风险不可忽略。研究结果可为今后稻菜轮作土壤农药污染监测与风险识别提供科学依据。  相似文献   

4.
For the estimation of intestinal absorption of polychlorianted dibenzodioxins/dibenzofurans (PCDD/F), ain-vitro model was developed in order to study PCDD/F mobilization by digestion of technogenic soils using ?Kieselrot” (red slag) as substrate and digestive juice model mixtures. Red slag samples were shaken successively with model mixtures of saliva, gastric juice, duodenal juice and bile. The solids were separated, the aqueous phase was extracted with hexane, the hexane extract analyzed for PCDD/F. Additionally, the PCDD/F-content of the red slag was determined. Extraction efficiency was tested with three different digestive juice model mixtures and also tap water for comparision. The percentage of PCDD/F transferred from the red slag sample into the digestive juice mixture was defined as absorption availability. In our experiments, a maximum absorption availability of 2 % was found.  相似文献   

5.
新烟碱类农药是目前被广泛用于农业中的一类作用独特、高效广谱的内吸性杀虫剂,它们在蔬菜水果中的残留对人体健康构成威胁。本研究目的是查明北京市场上蔬菜水果中不同新烟碱类农药的残留量,并对人群摄食暴露健康风险进行评估。从北京市场上采集49种蔬菜和24种水果,采用Qu ECh ERS–高效液相色谱串联质谱(HPLC-MS/MS)法测定蔬菜水果中9种新烟碱类农药的含量。利用测得数据和中国居民膳食结构调查资料,采用蒙特卡罗模拟方法计算了不同年龄段人群的日均经口摄入暴露量的概率分布,并采用商值法计算了新烟碱类农药的非致癌风险。结果显示新烟碱类农药普遍存在于北京市场上的蔬菜水果中。49种蔬菜样品中检出7种新烟碱类农药,其中吡虫啉、啶虫脒和噻虫嗪检出率均达100%,噻虫胺、烯啶虫胺、噻虫啉和呋虫胺的检出率分别为47%、14%、10%和4%。24种水果样品中检出5种新烟碱类农药,其中吡虫啉和啶虫脒的检出率均达100%,噻虫嗪、噻虫胺和噻虫啉的检出率分别为54%、13%和4%。不同新烟碱类农药在蔬菜水果中的含量范围为0.01 ng·g~(-1)~126 ng·g~(-1),均未超过我国食品安全国家标准或美国联邦管理条例中的限量值。小部分(约3%)人群因摄食蔬菜水果暴露于新烟碱类农药的非致癌风险商值大于0.1。新烟碱类农药在蔬菜水果中普遍存在,对人体健康有潜在的风险。  相似文献   

6.
A simple analytical method was developed and validated to determine fluopicolide residues in grapes and soil using the “Quick, Easy, Cheap, Effective, Rugged and Safe” approach followed by gas chromatography-mass spectrometry in the selected ion monitoring mode. Fluopicolide residues were extracted from grape and soil samples with acetonitrile, and the extracts were cleaned up by dispersive solid-phase extraction with primary secondary amine sorbent. The limit of quantification was 0.02 mg kg?1 with grape and soil samples spiked at three levels, and recoveries were from 95% to 101% and 94% to 101% with relative standard deviations from 0.2% to 4.4%. The method is less expensive and safer than existing analytical methods for grapes and soil.  相似文献   

7.
A freshwater fish species, Tilapia zillii, from Lake El-Manzala was analysed for concentrations of several organochlorine pesticides (OCs) and polychlorinated biphenyl (PCBs) in liver, gonads, mesenteric fat, flesh, and digestive tract in mature fish during the breeding season. PCBs and OCs were calculated in ng g-1 dry weight (dw) in homogenized samples. The obtained results revealed differences in lipid content between these different organs. The females showed a higher lipid content than did males. There was a significant positive correlation between the lipid content and the concentrations of detected organochlorines and PCBs. The results are concomitant with the lipophilicity of studied compounds. However, the recorded concentrations of these studied pollutants still do not exceed the international hazardous levels.  相似文献   

8.
Soil is damaged by several threats and, among them, chemical contamination by pesticides and compaction. However, the effect of compaction on the fate of pesticides in soil, and the impact of pesticides on soil biological functioning are unknown. Therefore, we studied the effect of soil compaction on the degradation of the herbicide isoproturon, and the impact of this herbicide on an enzyme activity (β-glucosidase) involved in the C soil cycle. Undisturbed soil samples were prepared at different bulk densities, treated with isoproturon then incubated at 18°C in darkness for 63 days. The results showed that soil compaction did not modify significantly the degradation of isoproturon, neither the formation rates nor the nature of its metabolites. Moreover, compaction did not modify the impact of isoproturon on β-glucosidase activity. To our knowledge, these are the first results concerning the interactions between soil compaction and the degradation and impact of a pesticide.  相似文献   

9.
A validated high-performance liquid chromatography–diode array detector method for simultaneous determination of the acaricide fenpyroximate on grape was developed. Estimated limit of detection and limit of quantification for fenpyroximate were 0.01 and 0.05 mg kg?1, respectively. The intra- and inter-day precisions performed with relative standard deviation were better than 9.3% and 8%, respectively, while recoveries were in the range of 88.5%–100.4%. Residue levels of fenpyroximate in grape samples collected 10 days after field application were below the established maximum residue level values. The dissipation rates of fenpyroximate were described using first-order kinetics and its half-life, were approximately 3.5 days in grape. This study provides basic information for developing regulations to safeguard the use of fenpyroximate in grapes and prevent any potential health concerns for consumers.  相似文献   

10.

Background

Drinking bottles and stove-top moka pots made of aluminum have become very popular. Storing drinks in bottles and preparing coffee in a moka pot may result in the migration of aluminum to the beverage.

Results/Conclusions

In a systematic study of aluminum drinking bottles, it has been shown that drinking a mixture of apple juice and mineral water in an aluminum bottle may reach 86.6% of the total weekly intake (TWI) for adults, and drinking tea from an aluminum bottle may exceed the TWI (145%) for a child weighing 15 kg. In contrast, preparing coffee in an aluminum moka pot results in a maximum of 4% to TWI, if an average of 3.17 L coffee is consumed per week, even if the pots are washed in the dishwasher, against the explicit instructions of the manufacturer.
  相似文献   

11.
Abstract

A large number of pesticides used in agricultural practice has been characterized or suspected to be Endocrine Disruptors, with dietary intake to be the major route of consumer’s exposure. In the present study the safety to consumer after the consumption of pome fruits and fruiting vegetables originated from the area of Thessaly, Central Greece was assessed. Objective samplings of 110 samples were conducted in local retail markets in an effort to quantify potential residues of targeted pesticides, previously characterized as endocrine disruptors. For the determination of residues, a QuEChERs-based multiresidue method coupled with liquid and gas chromatographic systems was applied and fully validated in accordance with the European Unions’s requirements in apples and tomatoes in three fortification levels. Acceptable results were obtained for all the validation parameters studied and the limit of quantification of 0.01?mg/kg and limit of detection of 0.0033?mg/kg were achieved. Based on the determined results, the most frequently determined pesticide was chlorpyrifos with a maximum concentration of 0.32?mg/kg in tomato samples. Cypermethrin and dimethoate were also determined in tomatoes and aubergines. The EFSA PRIMo rev.3.1 model was applied for all positive samples and acute risk for consumers was confirmed only in the case of determination of chlorpyrifos in tomatoes.  相似文献   

12.
In this study, risk assessment for visual disturbances among farm workers spraying agricultural pesticides in farms have been assessed. A cross-sectional study for the assessment of visual disturbances was undertaken using questionnaire survey and clinical examination among agricultural workers exposed to pesticides. Two hundred and thirty nine pesticide sprayers participated in the study. The study was compared to 110 controls not occupationally exposed to pesticides with similar socio-economic status. The prevalence of ocular morbidity was found to be 40% among pesticide sprayers which was significantly higher (p?p?相似文献   

13.
淮河流域安徽段水体成组生物毒性评价   总被引:1,自引:1,他引:0  
在淮河流域安徽段某区域采集了3个地表水样和12个地下水样,通过大型溞急性毒性(活动抑制)、微核及SOS/umu试验,分析了这些水样的急性毒性及遗传毒性。结果表明,急性毒性测试中,该区域地表水及大部分地下水的急性毒性均未超过US EPA废水排放毒性的控制要求(0.3 TU),有2个位点的地下水样毒性当量为0.31 TU,超过限值;经t-test分析,地表水的急性毒性显著高于地下水。SOS/umu检测中,2个地表水样和7个地下水样的结果呈阳性,表现出DNA损伤效应,其诱导率IR在(2.20±0.063)~(3.36±0.067)之间,对应的致癌风险P基本处在10-6~10-7水平。微核检测结果表明,3个地表水样具有较严重的染色体损伤效应,9个地下水样表现为阴性。总之,该区域地表水急性毒性及遗传毒性相对较高;部分浅层地下水也存在一定程度的急性毒性和遗传毒性,致癌风险处在可接受范围,但仍可能对周围居民的健康产生潜在威胁;而深层地下水没有检测到任何毒性效应。研究为周边居民饮水安全和人体健康提供了基础信息。  相似文献   

14.
A study was performed in a Protected Area (Natural Reserve of Sado Estuary) in 1996, to evaluate the acute toxicity for aquatic life of surface water from rice fields treated with pesticides, particularly with molinate and quinclorac. As a preliminary assessment, the following rapid toxicity tests were used: “Rotoxkit F”;, “Thamnotoxkit F”; and the recently introduced “Daphtoxkit F magna”; and “Algaltoxkit F”;. Water samples were collected from: a water source for irrigating the rice fields, two rice plots, a drainage channel and from Sado river in which the water is discharged. The results showed that samples from the rice plot treated with molinate were more toxic than those obtained from rice plot treated with quinclorac. Water samples from the river were the most toxic, causing 100% of immobility in all organisms and a substantial inhibition in the algal growth. Water collected from the drainage channel in late July, was also found to be quite toxic. The results obtained until now indicate that some characteristics of these microbiotests, like their rapidity, simplicity and relatively low cost, make them a practical tool to evaluate acute effects of pesticides in freshwater ecosystems. They may also contribute to suggest some changes in pesticides use to promote agricultural practices with lower impact to aquatic life.  相似文献   

15.
北京市郊再生水灌区土壤有机氯农药垂向分布特征   总被引:3,自引:0,他引:3  
在北京市郊再生水灌区采用正三角型布点法进行了3个钻孔的采样工作,钻孔间隔为1m,从表层开始每隔0.5m取一个样,3个钻孔共36组样品,同时采集钻孔附近的灌溉水及地下水,分别测试了土壤的理化参数及其土壤、灌溉水及地下水中9种有机氯农药的质量分数。测试结果表明:表层土壤是有机氯农药的主要残留层,表层土壤中检出的DDTs和BHCs质量分数较高,分别为2814.21ng·kg^-1和1130.41ng·kg^-1,但均符合土壤环境质量一级标准,残留污染程度较轻;其他层位以七氯和艾氏剂为主要检出物,最高质量分数分别为1286.19ng·kg^-1和781.23ng·kg^-1;其中艾氏剂未在表层土壤中检出;灌区内未检出的γ-BHC和(DDE+DDD)/DDT的计算值为1.80,都说明近期内没有新污染源的输入;检出的有机氯农药在土壤剖面上的迁移能力有HEP〉ALD〉BHCs〉DDTs〉HCB,与地下水中检出的规律一致。  相似文献   

16.
针对我国果园长期沿用清耕除草方式所带来的水土流失、土壤肥力下降和果品品质变劣等问题,于1999年在山东省烟台市5个试验点分别设置了由种草样地及其清耕对照样地组成的5组可比样地,对苹果园间种白三叶草(Trifoliumrepens)对土壤生态和果树生产的影响进行定位观测。结果表明:果园种草3a后0—30cm土层有机质含量平均提高3. 3g·kg-1,氮、磷、钾等养分含量有较大提高,尤以表层土壤更明显;土壤含水量得到提高,尤以夏秋多雨季节更明显;种草果园地下5cm处土温夏季比对照平均降低4. 1℃,而冬季升高2. 5℃,使土温的全年变化较为缓和;种草果园果品产量平均增加7. 04%,年产牧草2 130kg·hm-2,每年可增加经济收入5 328元·hm-2。  相似文献   

17.
The 30 species of limnic and marine fishes analyzed in the present study represent excellent foods for inclusion in diets that require a low sodium content. In none of these species, not even in the marine ones, did the content of sodium exceed the maximum amount (100 mg/100 g fish meat) specified by food authorities for low sodium diets.  相似文献   

18.
The levels of dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE), endosulfan, endosulfan sulfate, carbofuran, and cartap were determined in muscles of Cyprinus Carpio sampled from 10 different sites of River Ravi between Shahdara to Balloki Headworks to assess level of contamination of these pesticides by GC-ECD (gas chromatograph equipped with electron capture detector) method. All fish samples were found contaminated with different concentrations of DDT, DDE, endosulfan, and carbofuran. DDT and DDE concentrations were higher than maximum residue limits (MRL) in food standards, while endosulfan sulfate and cartap were not detected. These findings indicate that pesticide concentrations in fish muscles decreased in the order: DDT > DDE > carbofuran > endosulfan. Furthermore, the sampling sites after Degh fall and beyond Hudiara Nulla Fall river sampling sites were more polluted. It is proposed that constant monitoring programs are needed to assess potential exposure risks.  相似文献   

19.
A laboratory study was conducted to assess the impacts of diazinon, linuron or a fungicidal preparation of mancozeb supplemented with dimethomorph on dehydrogenase activity (DHA) in loamy sand (LS) and sandy loam (SL) soils with different features. The pesticides were applied at the maximum predicted environmental concentrations (PEC) under field conditions and at 5 or 100 times the PEC. More distinct effects were observed in LS than SL soils at all sampling times. For PEC, a significant decrease in DHA was found in LS soil treated with diazinon or the fungicidal preparation on day 1 and during the incubation period, respectively. However, DHA did not decrease in SL soil treated with the pesticides at this dosage. For the higher concentrations, decreased DHA was ascertained in LS soil treated with diazinon and the fungicidal preparation at all sampling times, whereas for linuron this effect was evident on days 14 and 28. By contrast, only 100-fold PEC significantly decreased DHA in SL soil amended with diazinon or linuron, compared with the fungicidal preparation that decreased DHA at five-fold PEC. Our results indicate that DHA was particularly sensitive to the fungicidal preparation in both soils, whereas linuron was less harmful than diazinon.  相似文献   

20.
The levels of cadmium (Cd), chromium (Cr), and copper (Cu) were assessed in 24 fruit species in Meerut, North India using atomic absorption spectrometry. Data showed that Cd concentrations in fruits except banana, pomegranate, papaya, orange, and cherry were above the recommended maximum allowable limit of Food and Agriculture Organization (FAO)/World Health Organization (WHO) (0.2 µg/g). Average Cr concentrations in all analyzed fruit samples were also found higher than the safe limit of FAO/WHO (2.3 µg/g). In contrast, fruits viz. banana, lychees, papaya, Indian apple, Asian apple, and tiger nut showed concentration of Cu below the recommended safe limit (40 µg/g). Our study demonstrated that concentration of studied heavy metals in all tested samples varied according to fruit species and respective contaminants. Data suggest that more strict rules/standards need to be applied by National/International regulatory agencies in order to make these important fruit items free from heavy metals contamination and protect the consumer.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号