色谱法测定肉及肉制品中敌草隆、绿麦隆、莠去津和西玛津残留量

敌草隆、绿麦隆系脲类除草剂,莠去津和西玛津系三嗪类除草剂。国外已有其检测方法的报道,我们在过去研究。的基础上扩展了除草剂的检测种类,结果令人满意。     

高效液相色谱-飞行时间质谱法筛查大豆中残留的多种除草剂和杀虫剂

应用高效液相色谱-飞行时间质谱建立了筛查大豆中77种除草剂和杀虫剂残留的新方法。在不同添加浓度下获得了精确的分子离子质量,质量偏差的绝对值低于3×10-6。所有除草剂和杀虫剂在0.03～1.00 mg/kg范围内线性关系良好（r≥0.99）。除一些除草剂外,多数除草剂和杀虫剂的添加回收率为60%～120%,在大豆基质中的检测限为0.003～0.026 mg/kg。该方法适合于大豆中多种除草剂和杀虫剂残留的分析检测需要,方法简便、高效、准确。     

磺酰脲类除草剂残留检测技术及其研究进展

磺酰脲类除草剂具有高效、低毒、低残留等特点,已经成为当前使用量最大的一类除草剂.随着该类除草剂在农业生产中的广泛使用,其残留问题以及对后茬作物产生的危害已经引起关注.由于磺酰脲类除草剂在环境和生物样品中痕量存在,且其化学和热不稳定,酸性条件下易水解,以及最大残留限量值日益严格,使其残留分析成为一项极具挑战性的工作.该文综述了近年来磺酰脲类除草剂残留分析的前处理方法和检测技术的研究进展,并详细介绍了分子印迹技术、在线联用技术和液相色谱-串联质谱技术在该类除草剂检测中的应用及其前景,为今后分析检测各类样品基质中磺酰脲类除草剂的残留提供参考和依据.     

除草剂最近的发展

一、各国除草剂应用现状化学除草剂的应用不仅是保证农作物不受杂草危害的手段,而且是节省劳动力的一项重要措施。最近各国曾提出使用除草剂可以不必翻耕土地就能达到从播种到收获的效果,如果这种新措施能普遍推广,它将打破传统的耕作制度,掀起农业生产上的一个革命。由于除草剂具有节省劳动力的突出优点,近年来,它的发展速度是其他农药所赶不及的。美国除草剂生产增长速度超过了杀虫剂和杀菌剂。英国除草     

除草剂研究的进展

前言自从四十年代利用人工合成的化学除草剂2,4-滴进行化学除草以来,世界各国研究与合成了许多有机除草剂,到目前为止,大量生产和应用的品种不下百余种。六十年代以前世界上农药的发展是以杀虫剂为主,其次为杀菌剂和除草剂。到六十年代以后,各国化学除草剂的产量和品种增长的速度都较杀虫剂和杀菌剂为快,因为大多数除草剂对人畜毒性低,无积累中毒危险,而且使用化学除草剂既节省人工,又促进农作物增产。     

薄层色谱法半定量分析抑制光合作用的除草剂的残留

我们采用希尔反应对9种能抑制光合作用的除草剂在薄层色谱(TLC)上的定位及半定量进行了探索。除草剂在薄层板上展开后,喷有小麦嫩叶离体的叶绿体和2,6-二氯酚靛酚钠盐的混合溶液在光照射下,在板上无除草剂的部位水分解,放出氧。2,6-二氯酚靛酚钠盐被还原后,颜色由蓝色变成无色,而板上有除草剂的部位抑制了希尔反应,不能产生氧气。因此,在薄层板上显色的背景是绿色,除草剂的斑点是蓝灰色,据此可以检测除草剂的残留。     

气相色谱检测尿液中丁草胺

农药中除草剂的使用在农业作业区非常普遍,尤其是以丁草胺为代表的酰胺类除草剂作为防治一年生禾本科杂草的特效除草剂应用十分广泛.由丁草胺引起的投毒、自杀和误服等中毒案件近年来也呈上升趋势.目前,关于酰胺类除草剂的研究主要集中在对其各种制剂~([1])和环境残留~([2,3])的检验方面,而关于中毒者体内检材中酰胺类除草剂的分析研究却少见报道.因此,研究生物样品中酰胺类除草剂的分析检验方法具有一定的理论意义和实际应用价值.本研究建立了尿液中丁草胺的液液萃取-气相色谱检测方法.本方法将有助于对酰胺类除草剂中毒案件的检验研究.     

水中氯代苯氧酸类除草剂测定方法的研究进展

氯代苯氧酸类除草剂是广泛使用的主要除草剂之一,由于具有一定的毒性,是环境中重点关注的一类污染物。对水中氯代苯氧酸类除草剂的检测标准和检测方法研究的进展进行了综述,对各种检测方法的优缺点进行了比较。     

一类新型ALS抑制剂的分子设计、合成及生物活性

嘧啶(硫)醚类化合物是继磺酰脲和稠杂磺酰胺类除草剂之后的所开发出的又一类以乙酰乳酸合成酶(ALS)为作用靶标的超高效除草剂^[1]。与磺酰脲(胺)类除草剂相比较,这类除草剂的结构变化则更为灵活,合成也相对较为容易,因而近年来关于这类除草剂的专利文献不断见诸报道,已经成为当前除草剂研究中的一大热点。     

虚拟分子印迹固相萃取技术检测食品中10种三嗪类除草剂残留

以正丁基三聚氰胺为虚拟模板,α-甲基丙烯酸为功能单体,乙二醇二(甲基丙烯酸)酯为交联剂,采用悬浮聚合法制备得到对三嗪类除草剂具有高选择性的分子印迹聚合物。运用分子模拟技术探讨了虚拟模板的筛选方法;利用高效液相色谱法考察了印迹聚合物对三嗪类除草剂的选择吸附性;以此聚合物作为固相萃取填料,研究了分离、富集食品中三嗪类除草剂的最佳萃取条件。与其它固相萃取柱相比,所制备的分子印迹固相萃取柱对三嗪类除草剂有较好的分子识别能力,能有效降低基质效应。基质加标三嗪类除草剂回收率为87.8%～105.2%;相对标准偏差(RSD)均小于13%(n=6)。     

Controlled release of volatiles under mild reaction conditions: from nature to everyday products

Volatile organic compounds serve in nature as semiochemicals for communication between species, and are often used as flavors and fragrances in our everyday life. The quite limited longevity of olfactive perception has led to the development of pro-perfumes or pro-fragrances--ideally nonvolatile and odorless fragrance precursors which release the active volatiles by bond cleavage. Only a limited amount of reaction conditions, such as hydrolysis, temperature changes, as well as the action of light, oxygen, enzymes, or microorganisms, can be used to liberate the many different chemical functionalities. This Review describes the controlled chemical release of fragrances and discusses additional challenges such as precursor stability during product storage as well as some aspects concerning toxicity and biodegradability. As the same systems can be applied in different areas of research, the scope of this Review covers fragrance delivery as well as the controlled release of volatiles in general.     

三明治式双极膜的制备及其光催化性能

以Cr3+交联羧甲基纤维素钠(CMC)作为阳膜层,戊二醛改性壳聚糖(CS)作为阴膜层,纳米TiO2光催化剂作为双极膜的中间层,在TiO2上涂布光敏剂八羟基喹啉（Oxine）以增强其光催化解离水的性能,制备了三明治式的双极膜（mCMC/TiO2-Oxine/mCS BPM)。 该双极膜在紫外光照射下,具有高的水解离效率,优良的亲水性能,双极膜阻抗小,工作电压低,当工作电流密度达0.12 A/cm2时,电槽工作电压小于5.0 V。     

咪草烟分子印迹聚合物的制备及其选择性吸附性能的研究

以丙烯酸为聚合单体,TMPTA为交联剂,AIBN为引发剂,咪草烟为模板分子,采用在低温光聚合的方法,制备了对咪草烟分子具有选择性识别能力的分子印迹聚合物．通过IR和HPLC表征,咪草烟分子印迹聚合物对咪草烟分子具有良好的识别作用．     

双氧水氧化环己烯催化合成己二酸研究进展

评述了近年来以环己烯为底物,双氧水为氧源,分别采用钨酸盐、钨酸、杂多酸及杂多酸盐、功能化分子筛和负载离子液体等为催化剂催化合成己二酸的研究进展.     

Enzyme-based biocatalysis for the treatment of organic pollutants and bioenergy production

Enzyme-based biocatalysis is emerging as an advanced technique to develop green processes that help to maintain the sustainability of the environment. The bioremediation of toxic organic pollutants and waste to bioenergy production using enzymes as biocatalysts is rapidly growing due to its eco-friendly and sustainable nature. Additionally, a range of microbial species that typically grow on organic wastes can be used to produce these enzymes in an efficient manner. This is seen as a potential strategy for the development of cost-effective manufacturing for a number of biotechnological applications. The present study discusses biocatalysis as a promising and sustainable method toward the bioremediation of hazardous organic pollutants as well as for bioenergy production, based on the immense potential of enzymes as biocatalysts. Emphasis has been placed on evaluating the critical elements that can enhance the production of enzymes used as biocatalysts, as well as their functional effectiveness and stability.     

Macromolecular chemistry and medicine

Macromolecular substances are used in medicine both as materials and as reagents. In the former category polymers serve as replacements for soft tissue, as cardiovascular and orthopedic implants, and as adhesives. When employed as reagents, macromolecules interact with living tissue and play an active part in bodily repair processes.     

Chemical reaction and Soret effects on MHD convective flow of second grade fluid through an absorbent medium with ramped wall temperature as well as ramped surface concentration

In the present paper, the heat generating and/or absorption as well as thermo-diffusion on the unsteady free convection MHD gyrating flow of radiation and chemical reactive second grade fluid past an unbounded perpendicular plate during absorbent medium have been discussed. Here, it is assumed that, the confining plate has the ramped wall temperature with ramped surface concentration and isothermal temperature with ramped surface concentration. The analytical solutions for the governing equations are found by utilization of Laplace transformation methodology. The velocity, temperature and concentration profiles are analyzed with quite few figures. It is determined that, velocity, temperature and concentration distribution sketches in case of ramped temperature as well as ramped surface concentration are not as much of as those of isothermal temperature as well as ramped surface concentration. In addition to the idioms of skin friction, Nusselt number as well as Sherwood number are achieved and characterized numerically with tabular format.     

Aptamers: molecular tools for analytical applications

Aptamers are artificial nucleic acid ligands, specifically generated against certain targets, such as amino acids, drugs, proteins or other molecules. In nature they exist as a nucleic acid based genetic regulatory element called a riboswitch. For generation of artificial ligands, they are isolated from combinatorial libraries of synthetic nucleic acid by exponential enrichment, via an in vitro iterative process of adsorption, recovery and reamplification known as systematic evolution of ligands by exponential enrichment (SELEX). Thanks to their unique characteristics and chemical structure, aptamers offer themselves as ideal candidates for use in analytical devices and techniques. Recent progress in the aptamer selection and incorporation of aptamers into molecular beacon structures will ensure the application of aptamers for functional and quantitative proteomics and high-throughput screening for drug discovery, as well as in various analytical applications. The properties of aptamers as well as recent developments in improved, time-efficient methods for their selection and stabilization are outlined. The use of these powerful molecular tools for analysis and the advantages they offer over existing affinity biocomponents are discussed. Finally the evolving use of aptamers in specific analytical applications such as chromatography, ELISA-type assays, biosensors and affinity PCR as well as current avenues of research and future perspectives conclude this review.     

Dithiocarbamates as Precursors in Organic Chemistry; Synthesis and Uses

Abstract

Organic dithiocarbamates have received great attention due to their interesting chemistry and wide utility as radical precursors and intermediates in organic synthesis. They also have found many of applications, that is, in agriculture and medicine. They are in use as pesticides, as well as in the rubber industries as vulcanization accelerators; and as antioxidants. Because they exhibit strong metal-binding capacity, they can act as in inhibitors of enzymes and have a profound effect on biological systems. Moreover, they have found application in the treatment of cancer and HIV.     

Low-field NMR for quality control on oils

Oil is a prominent, but multifaceted material class with a wide variety of applications. Technical oils, crude oils as well as edibles are main subclasses. In this review, the question is addressed how low-field NMR can contribute in oil characterization as an analytical tool, mainly with respect to quality control. Prerequisite in the development of a quality control application, however, is a detailed understanding of the oils and of the measurement. Low-field NMR is known as a rich methodical toolbox that was and is explored and further developed to address questions about oils, their quality, and usability as raw materials, during production and formulation as well as in use.