好年冬在土壤和苹果中残留测定方法的研究

报道了好年冬,呋喃丹和三羟基呋喃丹在土壤和苹果中的残留测定方法。     

快速测定果蔬中农药残留量的方法研究

用自行研制的便携式农药残留速测仪，对果，蔬中农药残留毒性进行快速检测，可以直接显示有机磷和氨基甲酸酯类药对乙酰胆碱酶的抑制率，确定农药残留毒性水平。     

加工过程对水果及其制品中农药残留的影响

综述了国内外加工过程对水果中农药残留的影响,着重讨论了原料前处理和灭菌,以及榨汁、澄清、过滤、干燥、发酵等对农药残留的影响及其控制措施,并对今后该领域的发展前景进行了展望,以期为水果制品生产中减少农药残留、保障消费者食品安全提供一定的参考。     

蔬菜中氯氰菊酯残留的风险评估研究

目前使用的绝大多数农药为合成农药,具有急性毒性特征,已开展的慢性评估不能完全符合实际需要,慢性评估结果容易出现过低估计风险,具有急性毒性特征的农药残留必须开展急性评估。为了推进急性评估研究,为我国食品安全监管和残留限量的制定提供技术支持,在WHO原则指导下、基于JMPR建议的方法,开展了蔬菜中氯氰菊酯残留的急性和慢性点评估技术研究。结果显示,济南、青岛和寿光三地市售的西红柿、菜椒、菜豆、茄子、豇豆和芹菜中氯氰菊酯残留摄入是安全的;虽然白菜出现了超标的个例,但99.98%的氯氰菊酯残留摄入不存在危害健康的摄入风险;即使考虑50%的总体误差以及蔬菜占总食物摄入量的比例,至少99.96%的残留摄入不存在危害健康的摄入风险。研究表明,摄入频率高的7类蔬菜中氯氰菊酯残留污染较轻,对消费者（包括孕妇、婴儿和儿童）身体健康危害很小。     

紫外线降解水果中农药残留设备的设计与试验

为探讨高效降解水果中农药残留的方法,设计了紫外线降解农药残留的设备,利用紫外线照射水果表面,使水果中的农药残留发生降解。同时以乔纳金苹果和砀山酥梨为试验材料,研究了该设备的使用效果情况。研究结果表明：用波长为253.7 nm,有效强度为2243 μW/cm2的紫外光分别照射农药残留超标的苹果和梨3、2、1、0.5 min, 与未经照射的对照组相比,经处理的水果农药残留均大幅度下降;综合来看处理1 min的效果较好。苹果和梨处理1 min后残留乐果的降解率分别是57.40%、60.12%;残留氰戊菊酯的降解率分别是42.23%、41.25%;处理后的苹果和梨中的农药残留均远低于国家标准。     

太湖地区农田土壤中氯代持久性有机污染物的残留和输入

Selected persistent organochlorine pesticides (OCPs), including 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT)and its principal metabolites 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), hexachlorocyclohexane (HCH) and its isomers (α-, β, γ-, and δ-HCH), hexachlorobenzene (HCB), endosulfan, dieldrin, and endrin were quantified to determine current levels of organochlorine pesticides, to assess the ecotoxicological potential, and to distinguish previous and current inputs in agricultural soils from the Taihu Lake region.Gas chromatography equipped with a 63Ni electron-capture detector (GC-ECD) system was employed. Thirteen OCPs were detectable in all soil samples, with DDTs being the main residues, and HCHs had the second highest level of OCP residues. Although OCP residual levels were lower than those in 1990s, the residual levels for most of the DDTs and some of HCHs were still higher than the national environmental standards for agricultural soils. The ratios of DDT/DDE and γ-/α-HCH in twelve soils indicated that new inputs could be present in the soils. Thus, efforts should be made to completely ban the production of OCPs and their use in agriculture so as to reduce the threat of OCPs to food quality and human health.     

塞曼石墨炉原子吸收测定蔬菜、水果及制品中铬和钴

本文介绍了用塞曼石墨炉原子吸收测定蔬菜、水果及其制品中Ｃｒ和Ｃｏ的方法。样品经高温灰化，以磷酸二氢铵作基体改良剂，用平台热解涂层石墨管进行样品测定。经１１组白菜参考样测定验证，铬和钴的相对偏差分别为８．４％和９．０％；两组不同浓度的铬和钴的加标回收率分别９３－１０１％和９４－１０５％。铬和钴的检出限分别为０．４１μｇ／１和０．３９μｇ／ｌ。本法也适用于其它生物样品中Ｃｒ和Ｃｏ的测定。     

贮存温度条件对蔬菜基质中农药残留稳定性的影响

本研究对蔬菜样品中农药残留稳定性和变化趋势进行考察,采用直接在匀浆样本中添加农药的方法,并且为避免每次取出称样反复解冻对农药降解产生影响,进行等分分装密封贮存.温度条件为室温(25℃左右)、冷藏(0～4℃)和冷冻(-18℃左右);贮存期最长为379天.结果表明,冷冻条件及高浓度农药稳定性较好.不同农药降解趋势不同,其中百菌清稳定性最差,常温时百菌清10天内约降解90％,冷藏和冷冻分别降解40％和20％.毒死蜱、聚酯类农药稳定性较高.不同蔬菜种类间的差异不显著.农药残留通常是微量分析,样品宜冷冻储存,并应在3天内检测.     

土壤中有机磷农药的提取纯化和气相色谱-氮磷检测器测定

The objectives of this study were to optimize instrumental parameters and conditions for analysis of selected organophosphorus pesticides (OPPs) by gas chromatography (GG) with nitrogen-phosphorus detection (NPD) (GG-NPD); to select an appropriate solvent system; to conduct a comparison of sonication and shaking extractions; and to select an appropriate procedure for extracting organophosphorus pesticides from soils. Procedure Ⅰ consisted of n-hexane or petroleum ether together with acetone used as solvents, while Procedure II contained several solvents including acetone,methanol, dichloromethane, and n-hexane or petroleum ether. Experimental results indicated that a mixture of petroleum ether/acetone (2:1, v/v) could be used in place of n-hexane/acetone (2:1, v/v) as it was a less expensive solvent system.In addition, shaking under a water bath at 20℃ was more effective than sonication. Also, Procedure Ⅰ was more effective,safer, and more timesaving than Procedure Ⅱ. Procedure Ⅰ was applied to three soil types of different organic matter content, with recoveries of the OPPs from the yellow-brown soils, which had a higher organic matter content, being lower than those from the yellow and red soils.     

60Coγ射线辐照对水果蔬菜中维生素C的影响

维生素C是水果蔬菜中重要营养成分之一,是人体中重要的生物活性物质,但很多因素会影响水果蔬菜中的维生素C含量。有关60Co γ射线辐照对水果蔬菜中维生素C含量有一定的影响,但文献报道差异性较大,一些报道辐照能降低水果蔬菜中维生素C的含量,也有一些文献则认为辐照对维生素C含量无明显影响。导致辐照对水果蔬菜维生素C影响结果不一致的因素主要有抗坏血酸氧化酶、水果蔬菜本身化学成分、辐照剂量、辐照环境、水果蔬菜生理代谢等。辐照处理是果蔬保藏的重要技术手段,虽然辐照对维生素C含量有一定的影响,但不足以影响辐照技术在果蔬贮藏保鲜方面的应用,况且通过合适的技术处理还可以避免或减少其影响的程度。本文对相关文献的研究结果进行了归纳分析,为更好地利用辐照技术在水果蔬菜保鲜加工中的科学应用提供借鉴。     

蔬菜农药残留速测方法中若干问题的探讨

随着“无公害蔬菜”、“放心菜”工程的开展,蔬菜上农药残留速测技术备受关注,各种速测方法应运而生,作者对常见的几种速测技术的原理与方法进行了评价,对目前速测方法中存在的重现性差、灵敏度低、误差大、实用性差等问题进行了讨论,为防止未成熟产品、伪劣产品流入市场,影响“三绿工程”的正常开展,提出建立多学科协作研究体系,把农药残留速测技术提高到一个新水平。