045 水中农药的生物检测技术

生物检测技术以其高效、快速、低成本的优势,越来越多地应用于水体农药残留的监测和现场检测.本文综述了近年来一些生物检测技术如免疫分析法、生物传感器法和指示生物法在水中农药检测方面的应用.     

水中农药的生物检测技术

生物检测技术以其高效、快速、低成本的优势，越来越多地应用于水体农药残留的监测和现场检测。本文综述了近年来一些生物检测技术如免疫分析法、生物传感器法和指示生物法在水中农药检测方面的应用。     

食品中有机氯农药检测方法的研究进展

主要阐述了有机氯农药的毒性作用以及近年来食品有机氯农药测定方法的研究进展,介绍了气相色谱技术、高效液相色谱技术、色谱-质谱联用技术等常见的检测技术,以及酶抑制法、免疫分析法、生物传感器法、活体检测法等快速检测方法的研究进展。     

酶抑制率法检测蔬菜中农药残留量

通过酶抑制率法检测市售蔬菜样本的农药残留分析,结果表明,酶抑制率法测定农药残留超标率简便、快速、成本低,测定方法应用和推广前途较为广泛。     

食品卫生

广西5城市农产品铅镉污染分析;用气-质联用技术检测葱、蒜、韭菜中多种农药残留量时试样预处理方法;流动注射式酶生物传感器检测蔬菜中农药残留的定量标准的研究;蔬菜及水果中77种有机磷和氨基甲酸酯农药残留量检测技术研究;高效液相色谱-串联质谱法测定粮谷中9种氨基甲酸酯类农药残留     

蔬菜中农药残留的分光光度法快速检测

目前。有机磷和氨基甲酸脂类农药的检测方法，有国家标准方法即气相色谱方法及非国标的农药残留毒性快速测定仪。气相色谱法灵敏度高、分辨率高，能够较准确的定量检测出有机磷和氨基甲酸脂类农药的浓度及种类，但检测时间长，必须配有火焰光度检测器(FPD)或氮磷检测器(NPD)，并有适合的色谱柱等限制。农药残留毒性快速测定仪通过农药对酶的抑制可检测出样品中农药残留的总量，具有简单、快速、成本低等特点，但需要专用仪器。本文根据农药残留毒性快速测定仪的测定原理，用常用的分光光度法代替该仪器方法检测蔬菜中农药残留。结果表明，分光光度法、农药残留毒性快速测定仪同样可以快速检测蔬菜中的农药残留。现报告如下。     

拟除虫菊酯类农药残留检测的研究进展

随着拟除虫菊酯类农药在全球范围内的推广和使用,农药残留问题不容忽视。该文对近年来拟除虫菊酯类农药残留的气相色谱法、液相色谱法、光谱分析法、免疫分析法和电化学传感器技术的发展进行综述,并对其进行展望。     

蔬菜中农药残留快速检测方法的探讨

目前有机磷和氨基甲酸脂类农药的检测方法有气相色谱法及快速测定方法-酶抑制法。气相色谱法是国家标准方法，要求条件较高，必须具备气相色谱仪并配有火焰光度检测器(FPD)，或氮磷检测器(NPD)，有适合的色谱柱等。该方法具有灵敏度高、分辨率高的特点，能够较准确的定量检测出有机磷和氨基甲酸脂类农药的浓度及种类。快速检测方法虽不是国标法，但具有检测快速设备和试剂简单、成本低特点，适合水果蔬菜上市前农药残留毒性的检测。     

生物传感器在食品安全检测中的应用

“苏丹红、农药残留、瘦肉精”等食品的安全性问题日益受到人们的重视，各个国家都积极建立食品安全分析有效标准方法，传统方法主要是分光光度法、色谱法（GC、HPLC）和各种电泳技术。但这些方法分析速度慢，样品需要进行前处理，且不能进行连续检测。与传统的分析方法相比，生物传感器具有选择性好、无需试剂、操作简便、可重复使用及在线分析等优点，广泛应用于食品中的微生物及其产生的毒素、添加剂、农药及兽药残留、以及激素等多种物质的检测。本文主要就生物传感器及其在食品安全检测中应用现状及发展趋势作一综述。     

有机磷农药残留快速检测方法研究进展

最初农药残留检测技术仅限于化学法、比色法和生物测定法，检测方法缺乏专一性，灵敏度也不高。20世纪60年代气相色谱应用于农药和药物残留分析，大大提高了农药和药物残留量的检测水平。20世纪80年代以来，高效液相色谱法开始广泛应用于对热不稳定和离子型农药及其代谢物的分析。色谱法虽然定量准确、灵敏度高，但所需设备昂贵，需要专业人员操作，且分析时间长不利于现场监测。本就当前农药和药物残留快速检测分析技术研究进展做一综述。     

The politics behind the implementation of the WTO Paragraph 6 Decision in Canada to increase global drug access

Background

The U.S. imports a substantial and increasing portion of its fruits and vegetables. The U.S. Food and Drug Administration currently inspects less than one percent of import shipments. While countries exporting to the U.S. are expected to comply with U.S. tolerances, including allowable pesticide residue levels, there is a low rate of import inspections and few other incentives for compliance.

Methods

This analysis estimates the quantity of excess pesticide residue that could enter the U.S. if exporters followed originating country requirements but not U.S. pesticide tolerances, for the top 20 imported produce items based on quantities imported and U.S. consumption levels. Pesticide health effects data are also shown.

Results

The model estimates that for the identified items, 120 439 kg of pesticides in excess of U.S. tolerances could potentially be imported to the U.S., in cases where U.S. regulations are more protective than those of originating countries. This figure is in addition to residues allowed on domestic produce. In the modeling, the top produce item, market, and pesticide of concern were oranges, Chile, and Zeta-Cypermethrin. Pesticides in this review are associated with health effects on 13 body systems, and some are associated with carcinogenic effects.

Conclusions

There is a critical information gap regarding pesticide residues on produce imported to the U.S. Without a more thorough sampling program, it is not possible accurately to characterize risks introduced by produce importation. The scenario presented herein relies on assumptions, and should be considered illustrative. The analysis highlights the need for additional investigation and resources for monitoring, enforcement, and other interventions, to improve import food safety and reduce pesticide exposures in originating countries.     

胆碱酯酶生物传感器检测农药残留物研究进展

旨在综述近年来以胆碱酯酶(ChE)作为生物识别元件的有机磷农药生物传感器的研究进展;评述了这类传感器在专一性、精确性、基体效应和酶的不可逆抑制等方面存在的问题,以及由此研究的一些新型检测方法;指出了设计灵敏的ChE突变体作为生物识别元件,以及开发多样品和多组分平行分析系统是这类生物传感器在商业化过程中的关键课题。     

In utero pesticide exposure, maternal paraoxonase activity, and head circumference

Although the use of pesticides in inner-city homes of the United States is of considerable magnitude, little is known about the potentially adverse health effects of such exposure. Recent animal data suggest that exposure to pesticides during pregnancy and early life may impair growth and neurodevelopment in the offspring. To investigate the relationship among prenatal pesticide exposure, paraoxonase (PON1) polymorphisms and enzyme activity, and infant growth and neurodevelopment, we are conducting a prospective, multiethnic cohort study of mothers and infants delivered at Mount Sinai Hospital in New York City. In this report we evaluate the effects of pesticide exposure on birth weight, length, head circumference, and gestational age among 404 births between May 1998 and May 2002. Pesticide exposure was assessed by a prenatal questionnaire administered to the mothers during the early third trimester as well as by analysis of maternal urinary pentachlorophenol levels and maternal metabolites of chlorpyrifos and pyrethroids. Neither the questionnaire data nor the pesticide metabolite levels were associated with any of the fetal growth indices or gestational age. However, when the level of maternal PON1 activity was taken into account, maternal levels of chlorpyrifos above the limit of detection coupled with low maternal PON1 activity were associated with a significant but small reduction in head circumference. In addition, maternal PON1 levels alone, but not PON1 genetic polymorphisms, were associated with reduced head size. Because small head size has been found to be predictive of subsequent cognitive ability, these data suggest that chlorpyrifos may have a detrimental effect on fetal neurodevelopment among mothers who exhibit low PON1 activity.     

Metabolic susceptibility to agricultural pesticides and non-Hodgkin's lymphoma

Epidemiologic studies have failed to establish clearly whether agricultural pesticides contribute to the genesis of non-Hodgkin's lymphoma (NHL). Discordant results may be related to variation in susceptibility factors, including metabolism gene polymorphisms that might influence lymphocyte exposures to active pesticide metabolites. Associations between NHL and polymorphisms that may be relevant to pesticide metabolism have been assessed, including CYP1A1 and glutathione S-transferase variants, but the results are not highly informative because estimates were based on small numbers and convenience samples of cases and controls. Butyrylcholinesterase and paraoxonase (PON1) enzyme variants associated with altered activity and acute organophosphate toxicity are strong candidate susceptibility factors for pesticides and NHL, but others may be identified as knowledge of pesticide metabolism and relevant polymorphisms improves. Studies of metabolic susceptibility must be large and include information on specific exposures and subtypes of NHL for results to further the understanding of the relation between agricultural pesticides and NHL.     

Bats at risk? Bat activity and insecticide residue analysis of food items in an apple orchard

Although bats are reported as being threatened by pesticides, they are currently not considered in European Union pesticide risk assessments. The reason for that contradiction is probably related to the scarcity of information on bat activity in pesticide-treated fields and the pesticide residues on their food items. The authors recorded bat activity and measured pesticide residues on bat-specific food items following applications of two insecticides in an apple orchard. High activity levels of the common pipistrelle bat, a foraging habitat generalist, were detected. Airborne foragers and bats that take part of their food by gleaning arthropods from the vegetation were recorded frequently. The initial value and the decline of pesticide residues were found to depend on the arthropod type, their surface to volume ratio, their mobility, and the mode of action of the applied pesticide. The highest initial residue values were measured on foliage-dwelling arthropods. By following the toxicity-exposure ratio approaches of the current pesticide risk assessment, no acute dietary risk was found for all recorded bat species. However, a potential reproductive risk for bat species that include foliage-dwelling arthropods in their diet was indicated. The results emphasize the importance of adequately evaluating the risks of pesticides to bats, which, compared to other mammals, are potentially more sensitive due to their ecological traits.     

To go or not to go organic: what choice for Pacific island countries?

There are arguments for and against organic agriculture. The paper looks at the impact of changes and development, the need for sustainable development, organic farming as a viable alternative, organic certification and concluding thoughts on why organic farming makes sense. To go organic does not necessarily mean that organic products are totally free of chemical pesticides but they have a lower pesticide residue. Organic certification, a process guarantee not a product guarantee, becomes necessary if a farmer has to sell organic food products locally (to tourists) or export overseas. For Pacific organic producers, the biggest obstacle lies with certification costs and initial investments in research and extension to educate consumers and farmers about organic agriculture organic methods.     

新鲜蔬菜中有机磷农药残留的胆碱酯抑制快速检测法

目的开发新鲜蔬菜农药残留量的快速检测技术。方法根据有机磷农药残留的胆碱酯酶抑制法原理,通过单因素和正交试验确定最佳反应条件,由指示剂颜色变化和反应液ApH进行定量。结果确定检测条件为：马血清0．8ml,1．0％氯化乙酰胆碱1．4ml,反应温度为33℃。该方法对常见的几种有机磷农药的检测限均在0．04—10．0mg／kg的范围。结论该方法操作简便,检测快速,成本低,因而在有机磷的快速测定中有广泛的应用价值。     

Laundering as decontamination of apparel fabrics: Residues of pesticides from six chemical classes

Research on reducing the level of pesticide residue on a textile substrate has examined many variables under many different conditions. This study controlled fiber type and the use of prewash product in an examination of residue levels for a number of pesticides in different pesticide classes.For all pesticides examined, the use of prewash lowered pesticide residues regardless of fiber type. Differences in pesticide residue level attributable to fiber type were not consistent.Journal Series No. 9737, Agriculture Research Division, University of Nebraska.     

An evaluation of residual organochlorine pesticides in popular Indian herbal teas

Herbal preparations are gaining popularity worldwide because of their history of use and the belief that they are free of harmful side effects. Among the most popular products are herbal teas, which are marketed extensively with emphasis on their medicinal properties. At the same time, the World Health Organization has been emphasizing the need for quality assurance of herbal products, including testing for inadvertent contamination. The authors conducted a quality-assurance evaluation of residual organochlorine pesticides in some popular brands of Indian herbal teas. Organochlorine pesticide residue build-up from agricultural or storage practices was estimated with gas-liquid chromatography. The results revealed scant presence of dichlorodiphenyltrichloroethane (DDT) or its metabolites; endosulfan--a highly toxic pesticide--was absent in all 8 brands of herbal teas studied. Hexachlorocyclohexane isomers were detected in 2 samples, but levels were below the permissible limit for pesticide residue in foods, as promulgated by the Codex Alimentarius Commission. The authors believe that all herbal preparations should be checked for toxic chemical residues to allay consumer fears of exposure to known neurotoxicant pesticides and to aid in promoting global acceptance of these products.     

An Evaluation of Residual Organochlorine Pesticides in Popular Indian Herbal Teas

Herbal preparations are gaining popularity worldwide because of their history of use and the belief that they are free of harmful side effects. Among the most popular products are herbal teas, which are marketed extensively with emphasis on their medicinal properties. At the same time, the World Health Organization has been emphasizing the need for quality assurance of herbal products, including testing for inadvertent contamination. The authors conducted a quality-assurance evaluation of residual organochlorine pesticides in some popular brands of Indian herbal teas. Organochlorine pesticide residue build-up from agricultural or storage practices was estimated with gas-liquid chromatography. The results revealed scant presence of dichlorodiphenyltrichloroethane (DDT) or its metabolites; endosulfan—a highly toxic pesticide-was absent in all 8 brands of herbal teas studied. Hexachlorocyclohexane isomers were detected in 2 samples, but levels were below the permissible limit for pesticide residue in foods, as promulgated by the Codex Alimentarius Commission. The authors believe that all herbal preparations should be checked for toxic chemical residues to allay consumer fears of exposure to known neuro-toxicant pesticides and to aid in promoting global acceptance of these products.