Dietary exposure of Hong Kong adults to pesticide residues: results of the first Hong Kong total diet study

The use of pesticides and other chemicals has become a common practice in modern agriculture to enhance and stabilise crop yield, protect the nutritional integrity of food, facilitate food storage to assure year-round supplies, and provide attractive and appealing food products. With the adoption of strict good agricultural practice (GAP), only minimal amounts of pesticide residues should remain on the crops or in connected foods of animal origin up the food chain. To assess their associated health risk to local people, the dietary exposure of Hong Kong adults to residues of four groups of pesticides or their metabolites – organophosphorus pesticides (OPPs), carbamates, pyrethrins and pyrethroids, and dithiocarbamate (DTC) metabolites – is estimated in the first Hong Kong Total Diet Study (TDS). A total of 150 commonly consumed food items were collected and prepared “as consumed”. A total of 600 composite food samples were analysed for 85 pesticides or their metabolites by liquid chromatography-tandem mass spectrometry (LC-MS/MS). These pesticides were primarily found at low levels (highest mean = 350 μg kg^?1) in food samples of plant origin such as vegetables and fruits. Dietary exposures to pesticide residues were estimated based on the analytical results and the food consumption data of the local residents. The estimated dietary exposures of Hong Kong adults to all individual pesticides were well below their respective acceptable daily intakes (ADIs). The percentage contributions of the estimated mean and 95th percentile dietary exposures to the ADIs of individual pesticides were <6% and <24% for the OPPs, <1% for the carbamates and pyrethrins and pyrethroids, and <1% and <4% for the DTC metabolites, respectively. The findings indicate that dietary exposures to all the pesticide residues analysed in this study were unlikely to pose unacceptable health risks to the Hong Kong population.     

天然除虫菊素对三种储粮害虫的触杀毒力测定

采用滤纸药膜法对玉米象、谷蠹、赤拟谷盗三种储粮害虫进行了天然除虫菊素的室内毒力测定。经72 h的毒力测定,天然除虫菊素对玉米象、谷蠹、赤拟谷盗的LC50分别为0．159 mg/cm2,0．251 mg/cm2和0．096 mg/cm2。天然除虫菊素对这三种储粮害虫具有触杀作用,不同虫种对天然除虫菊素的敏感性不同。     

Foliar and floral pyrethrins ofChrysanthemum cinerariaefolium are not induced by leaf damage

Pyrethrins are a class of potent insecticides produced byChrysanthemum cinerariaefolium. Simulated herbivory does not affect concentrations of pyrethrins in damaged and undamaged expanding and fully expanded leaves, or flowers of greenhouse or field-grown plants.     

毛细管气相色谱法测定天然除虫菊酯

研究了毛细管气相色谱法定量分析天然除虫菊提取液中6种酯的方法,FID检测,邻苯二甲酸二丁酯作为内标物。方法的线性范围为:0.1～1.0g/L:线性相关系数为0.9958～0.9964,平均回收率为99.50%(RSD=1.10%,n=5)。     

柿果实中菊酯类农药残留快速测定方法

建立了柿果实中菊酯类农药的提取及气相色谱测定方法。柿果实样品不经柱净化处理,采用恒温恒流气相色谱法测定的回收率为90．82％～96．83％,变异系数为1．04％～4．60％m=5）,最小检出限为0．001～0．006mg／kg,测定效果优于净化处理及程序升温测定,可以满足柿果实等材料中菊酯类农药残留量测定的质量要求。     

Residues of rotenone,azadirachtin, pyrethrins and copper used to control Bactrocera oleae (Gmel.) in organic olives and oil

Rotenone, azadirachtin, pyrethrins and copper fungicide decay curves were determined in olives and olive oil samples after experimental trials, consisting of one, two and three applications of each active ingredient, were carried out twice in 2005 and 2006. Rotenone, azadiracthin and pyrethrins were analyzed by extraction with acetonitrile and determined by liquid chromatography; copper was extracted into aqueous HCl and determined by chemical stripping. Pyrethrins were always found but in levels below the acceptable limits, whereas rotenone and copper residues always exceeded, after the pre-harvest interval, the maximum threshold allowed for olives. As regards residues in olive oil, rotenone was found in concentrations higher than those detected in olives. Copper accumulated in olives according to the number of applications, whereas, in oil, the residue was always lower than the maximum residue limit. The sensitivity of the method applied did not allow detection of azadirachtin.     

食品中菊酯类农药残留检测技术研究进展

菊酯类农药是模拟天然除虫菊酯化学结构发展而来的仿生农用药物,使用量仅次于有机磷农药。菊酯类农药对人体免疫、生殖、神经系统等多方面存在毒副作用,我国对其在食品中的残留限量作了严格的规定。随着剧毒、高毒农药禁用令的实施,加强食品中菊酯类农药残留监控显得更为重要,建立高效、快捷、准确测定食品中菊酯类农药残留的方法迫在眉睫。目前,QuEChERS法、微萃取、石墨烯技术等样品前处理技术,气相色谱-质谱联用、液相色谱-质谱联用等仪器分析技术及免疫标记法、化学分析快速检测法等快检技术成为了研究热点。本文主要综述了食品中菊酯类农药残留检测检测方法的前处理、色谱-质谱分析及快速检测技术应用的研究进展,并在此基础上结合食品安全监测的工作实际,对食品中菊酯类农药残留检测技术的发展趋势进行了展望。