农产品与环境中有害物质快速检测技术

农业环境与农产品中有害物质快速检测技术是当今环境科学的热点和重点．本书就是在此基础上，结合作者多年的研究成果及国内外该领域的最新进展编写而成。全书主要介绍了农药多残留快速检测技术的研究现状、农产品和环境中农药多残留快速检测技术、色谱-质谱联崩仪农药多残留快速扫描定性定量检测技术等内容．具有较强的参考性和应用价值。     

农产品/食品中农药残留快速检测方法研究进展

农药残留的识别和量化通常依赖于气相色谱法、高效液相色谱法、气/液相色谱-质谱联用法以及毛细管电泳法,这些方法需涉及大而贵重的仪器、费时的样品处理以及专门的技术培训。因此,建立在线、高灵敏度、高选择性、简单高效、低成本的农药残留快速检测方法和技术非常重要。该文综述了用于农产品/食品的农药残留分析快速检测方法,主要包括酶抑制法、免疫分析法、光谱法(包括可见/近红外、红外、拉曼和激光诱导击穿光谱等)以及各种生物传感器等,分别介绍了这些方法最新的研究进展,同时分析并总结了这些快速检测方法和技术的基本原理和特点。目前的研究在灵敏度、重复性、准确性方面存在着一些不足,商品化的农药残留检测仪器也比较单一。由于纳米生物技术、分子印迹技术和微流控技术等技术有着巨大的应用潜力,因此特别介绍了这些技术在农药残留分析中的应用。农药残留快速分析技术未来将会朝着检测仪器的小型化和集成化、多通道检测、无线通讯方向发展,提高快速检测方法和仪器的稳定性和可靠性是必然趋势。     

农药残留检测分析技术进展

农药在农作物病虫害的防治中具有不可替代的作用,农药使用导致农药在农产品中的残留,农药残留检测分析是保障食品安全的需要,本文介绍了农药残留检测的样品前处理和检测分析技术的进展。     

农产品农药残留检测中存在的问题及其对策

食品安全问题已经成为人们关注的主要问题,尤其是农产品的质量也引起了社会的广泛关注。但是,随着化工业的发展,农药成了主要杀虫药剂,造成了农产品中农药的残留问题日益严重,这就对农产品检测有了更高的要求。如果农产品中农药残留超标,不仅会对环境造成污染,还会对人们的身体健康产生危害,严重时可能导致食物中毒。基于此,对农产品中的农药残留检测问题和对策进行研究。     

QuEChERS提取法在农产品农药残留检测中的应用进展

食品中的农药残留检测长期以来一直是一项艰巨的挑战,其杂质干扰多,残留含量低,传统的提取方法常常因为无法将杂质分离而影响检测结果。由于食品中杂质种类众多,农药的种类繁多且理化性质各异,新型农药日益涌现,所以对样品的前处理提出了更高的要求。近年来,QuEChERS(Quick,Easy,Cheap,Effective,Rugged and Safe)作为一种新型的提取方法,由于具有快速、简单、廉价、有效、可靠、安全的特点,成为国内外广泛采用的样品前处理新技术,在多种农药、医药、兽药的气相或液相色谱分析中已经得到广泛应用。本文就国内外对QuEChERS法在各类食品以及其他动植物性农产品的农药残留检测中的应用和方法的改进进行了综述,并对QuEChERS法在今后农药残留检测的应用前景以及发展方向进行了展望。     

像巴菲特那样管理资金

农业环境与农产品中有害物质快速检测技术是当今环境科学的热点和重点．本书就是在此基础上，结合作者多年的研究成果及国内外该领域的最新进展编写而成。全书主要介绍了农药多残留快速检测技术的研究现状、农产品和环境中农药多残留快速检测技术、色谱-质谱联崩仪农药多残留快速扫描定性定量检测技术等内容．具有较强的参考性和应用价值。     

蔬菜农药残留快速检测技术的推广应用

随着我国经济水平的不断提高,农产品生产的重点逐渐从数量转移到质量安全方面。目前,国内农产品质量安全检测的主要是蔬菜中有机磷和氨基甲酸酯类二大类农药残留。国内用于农药残留的常用检测方法有气相色谱法和酶抑制法。气相色谱法成本高,适合用于定性定量检测;酶抑制法操作简便、成本低廉,适合用于定性的快速检测。实现对农产品中蔬菜、水果的农药残留监督,需要推行快速、简便、准确的检测方法,才能达到有效监控的目的。基于此,利用广东省开平市农产品质量监督检测站的技术力量和仪器设备,对目前华南地区占主流地位的4种农药残留快速检测仪器所应用的技术进行了一系列的试验,从而筛选出适用于当前情况的技术,进行推广应用,并调查验证推广应用的效果。     

生物传感器在农药残留检测中的应用

农药的广泛使用需要可靠的工具对其进行监测,从而保护人类和环境安全。传统的分析方法由于繁琐耗时或仪器的昂贵有其局限性。生物传感器是一种以生物活性单元为敏感元件,结合化学、物理转换元件,对被分析物具有高度选择性的仪器,可以用来检测农药残留等污染物。该文综述了近年来生物传感器在环境、食品和农产品农药残留检测中的研究进展。     

蔬菜中农药残留测定前处理方法综述

随着社会的进步和发展,人们的生活水平和质量越来越高,也对食品安全提出了更高的要求。蔬菜中农药的残留是影响食品安全的一大重要问题,因此,人们越来越重视蔬菜中的农药残留问题。基于此,通过对蔬菜中有机氯农药残留测定前处理方法的综述,从而促进我国农药残留检测前处理方法的发展。     

蔬菜中农药残留检测方法研究进展

对蔬菜中农药残留的前处理方法及检测方法进行了综述。固相萃取法(SPE)、超临界流体萃取(SFE)、毛细管气相色谱(CGC)、高效液相色谱(HPLC)及其联用技术是现阶段农药残留分析中的主要方法。     

Analysis of agricultural residues on tea using d-SPE sample preparation with GC-NCI-MS and UHPLC-MS/MS

This study presents new sample preparation and analytical procedures for the quantification of pesticides on processed tea leaves. The new method includes tea extraction and dispersive solid phase extraction (d-SPE) to prepare gas chromatography (GC) and ultrahigh-performance liquid chromatography (UHPLC)-ready samples, providing a fast and cost-effective solution for time-sensitive industrial analysis to fulfill regulatory requirements. Both GC-negative chemical ionization mass spectrometry (GC-NCI-MS) and UHPLC-tandem mass spectrometry (UHPLC-MS/MS) were employed to produce highly sensitive and reproducible data. Excellent limits of detection (typically below 1 μg/kg for GC and 10 μg/kg for UHPLC), wide linearity ranges, and good recoveries (mostly >70%) were achieved on the selected pesticides. Twenty-seven tea samples purchased from local grocery stores were analyzed using the newly developed methods. Among the pesticides analyzed, endosulfan sulfate and kelthane were the most frequently detected by GC-NCI-MS and imidacloprid and acetamiprid by UHPLC-MS/MS in these teas. The samples were found to be relatively clean, with <1 mg/kg of total pesticide residues. The organic-labeled teas were significantly cleaner than nonorganic ones. The cost per gram of tea did not correlate with pesticide residue levels detected.     

硝酸稀土对菠菜中毒死蜱残留的降解作用研究

菠菜是我国蔬菜出口的重要品种之一,其毒死蜱残留量直接关系到我国农产品的出口和消费者的安全。采用气相色谱法（GC-NPD）测定毒死蜱残留量,研究了硝酸稀土对菠菜中毒死蜱残留动态的影响。结果表明,不论是喷施农药之前2d还是喷施农药之后2d喷施硝酸稀土,不同的硝酸稀土对菠菜中的毒死蜱残留都有不同程度的降解作用,且随着喷药后时间的延长,毒死蜱在菠菜中的残留量逐渐减少。不同时间喷施硝酸稀土,对菠菜中毒死蜱残留降解的效果存在差异,药后喷施的效果优于药前喷施。在硝酸稀土种类的选择上,首先选择对毒死蜱降解效果好的硝酸铈和硝酸钕,其次选择常乐益植素和硝酸镧。根据稀土农用的安全性分析,参考植物性食品中稀土最大残留限量标准,选择硝酸稀土作为农药残留降解制剂用于蔬菜安全生产,在技术上是可行的,人类食用是安全的。     

低糖姜脯加工过程对甲基硫菌灵和多菌灵残留的影响

为研究低糖姜脯加工过程对生姜中甲基硫菌灵和多菌灵残留量的影响,以江永香姜为原料,通过浸药方式强化初始残留量,采用液相色谱串联质谱法测定各主要加工工序中2种农药残留量的变化,并计算2种农药在各工序中的加工因子。结果表明,在低糖姜脯加工过程中,除2次干燥工序,其他加工工序对甲基硫菌灵和多菌灵的残留水平均有一定的降低作用,全果清洗步骤多菌灵的去除率为31.1%,甲基硫菌灵的去除率高达62.3%;去皮工序甲基硫菌灵和多菌灵的去除率分别为82.0%和72.9%,漂烫工序甲基硫菌灵和多菌灵的去除率分别为36.8%和77.3%,硬化、超声辅助加热渗糖和上胶衣过程均对甲基硫菌灵和多菌灵的去除有一定的积极影响。在整个加工过程中,各工序姜脯样品的加工因子均小于1,低糖姜脯成品中的甲基硫菌灵和多菌灵的加工因子分别为0.010和0.023,表明整个加工过程可以显著降低姜脯中甲基硫菌灵和多菌灵的残留量(P<0.05)。本研究结果为生姜加工工艺的优化和农药残留的膳食暴露风险评估提供了数据支撑和参考。     

Comparison of accelerator mass spectrometry with gas chromatography for the determination of pesticide residues in individual items in the diets of wild birds and mammals

Methods to refine the assessment of exposure of wild birds and mammals to pesticides required measurement of pesticide residues in very small samples of their diets. Sample sizes were in the 1-100 mg range, and the target residue for measurement was 0.01 mg/kg. Gas chromatography-mass spectrometry (GC-MS) with large volume injection was compared with the use of an accelerator mass spectrometer (AMS) to measure residues of pesticide labeled at near-background levels with carbon-14. The GC-MS method was able to detect residues down to 0.1 ng per item of diet, and the AMS detected the radiolabel down to 1 mBq (0.06 disintegration per minute, 1 ng of pesticide at the specific activity used) per sample. The target residue level was achieved by the GC-MS method for samples down to 10 mg. The GC method appeared to be best suited to monitoring residues in field studies, and the AMS shows great potential for use in laboratory experiments concerning pesticide degradation.     

Food and Drug Administration pesticide residue monitoring of foods: 1983-1986

Pesticide residues in foods are reported for the 4-year period 1982-1986 [fiscal years (FY) 83-86]. Results were summarized from the 2 complementary approaches that make up the Food and Drug Administration's (FDA) pesticide residue monitoring program. Under regulatory monitoring, which focuses on residues in raw agricultural commodities, a total of 49,055 samples (27,700 domestic and 21,355 import) that included fresh fruits and vegetables, grains and grain products, milk and dairy products, seafoods, and a variety of processed foods were analyzed. No residues were found in 60 and 48% of the domestic and import samples, respectively, compared with 55 and 44% in FY78-82. About 3% of the domestic and 5% of the import samples were violative. In FY78-82, about 3 and 7% were violative, respectively. The other FDA monitoring approach, the Total Diet Study, was revised in April 1982 to expand coverage of age/sex groups, use updated diets, and provide for analysis of individual foods. Results from monitoring under this modified approach and from regulatory monitoring continued to demonstrate that pesticide residues in the U.S. food supply were well below regulatory limits, and dietary intakes were many times lower than the Acceptable Daily Intakes established by international agencies.     

Contributions of pesticide residue chemistry to improving food and environmental safety: past and present accomplishments and future challenges

The principles of modern pesticide residue chemistry were articulated in the 1950s. Early authors pointed out the advantages of systematizing and standardizing analytical methods for pesticides so that they could be widely practiced and the results could be reproduced from one laboratory to the next. The availability of improved methods has led to a much more complete understanding of pesticide behavior and fate in foods and the environment. Using methods based largely upon gas chromatography (GC) and high-performance liquid chromatography (HPLC) coupled increasingly with mass spectrometry (MS) and MS(n) as the detection tool, residues can be measured at parts per billion levels and below in a variety of food and environmental matrices. Development of efficient extraction and cleanup methods, techniques such as ELISA, efficient sample preparation techniques such as QuEChERS, and automated laboratory and field instrumentation has also contributed to the tools available for use in modern pesticide residue analysis. As a result, great strides have been made in improving food and worker safety and in understanding environmental behavior and fate of pesticides. There are many challenges remaining in the field of pesticide residue chemistry that will continue to stimulate analytical chemists. New chemistries are emerging, often patterned on complex natural products. Analyzing for the parent chemicals and potentially multiple breakdown products will require analytical ingenuity. The development of more sensitive bioassays and knowledge of unintended side effects will challenge residue chemistry as well, as in the case of following the fate of environmental endocrine disruptors associated with some pesticides as well as nonpesticide contaminants from packaging materials and other familiar articles. Continued funding and other resources to ensure better training, international cooperation, and accelerated research and development activities will be a constant need in pesticide residue chemistry as it is for all areas of science that aim to mitigate or eliminate contaminants that can affect human and environmental health and safety.     

葡萄酒发酵前后稳定同位素特征变化及初步相关性分析

为探讨葡萄酒发酵前后稳定同位素的特征变化,通过元素分析仪-稳定同位素比率质谱(EA-IRMS)对发酵前(全果、果汁与皮籽)样品和发酵后固体样品(皮渣和酒)中δ13C、δ15N、δ2H和δ18O进行了分析.结果表明,葡萄酒发酵前后各样品中δ15N、δ2H和δ18O均存在显著性差异;并且各元素的变化规律性不强,发酵前后相关...     

Characterization of benzyl isothiocyanate and phenyl acetonitrile from papayas by mass spectrometry

Two unidentified analytical responses in a papaya extract were structurally determined by mass spectrometry to be benzyl isothiocyanate and phenyl acetonitrile. Both these compounds have previously been shown to result from degradation of benzylglucosinolate that occurs naturally in the seeds of the fruit. Characterization by mass spectrometry has now provided a convenient mechanism to detect both these degradation compounds in extracts resulting from routine pesticide residue analysis.     

Electrochemical bioassay for the investigation of chlorpyrifos-methyl in vine samples

This paper reports the optimization of an electrochemical bioassay for the determination of chlorpyrifos-methyl and its application to the analysis of grape and vine leaf samples treated with that pesticide. The analytical method was based on electrochemical determination of the extent of the inhibition exerted by the pesticide on acetylcholinesterase using the substrate acetylthiocholine. Two similar calibration plots were obtained, in the range of 1-300 ng/mL, respectively, for chlorpyrifos-methyl in pure standard form and in the commercial preparation Reldan, with comparable coefficients of variation (CV) in the range of 10% < CV < 20%. After an insecticide treatment, samples were analyzed to evaluate its persistence both in grapes and in vine leaves. Samples were evaluated using different extraction procedures: one based on solvent extraction of pesticide residue from grapes and the other based on aqueous extraction from vine leaves using phosphate buffer. The grape solvent extracts were analyzed using both gas chromatography and electrochemical bioassay, whereas the vine leaf buffer extracts were analyzed using the electrochemical bioassay. Quantitative analysis of chlorpyrifos-methyl determined in the two samples, with the electrochemical bioassay, showed a comparable decrease profile over the experimental period.