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1.
农药久效磷分子印迹聚合物合成及其亲合性评估   总被引:11,自引:1,他引:11  
有机磷农药药效高、易于被水、酶和微生物所降解,残留毒性小,但由于不合理利用等因素,粮食、蔬菜、水果和环境中的有机磷农药残留严重超标,其危害引起了各国政府、学术界、民众的高度重视.目前有色谱法、酶法和免疫法等,这些方法的应用都受到客观因素的限制.因此研制类似于酶和抗体的高选择性、低造价、稳定性好的吸附材料用于食品和环境中有机磷农药残留的富集、分离纯化和分析尤为重要.  相似文献   

2.
气相色谱最优化分离多种有机磷农药   总被引:1,自引:0,他引:1  
王琴孙  陈端美 《色谱》1987,5(3):171-174
引 言 多种有机磷农药的色谱分离,一直是农药残留分析的重要方面,我们利用气相色谱FPD检测器,根据R.J.Laub等提出的气相色谱窗图最优化方法,选择较好的窗图,对12种有机磷农药进行了分离,发现当用86%的4%DC-200Chromosorb W.HP100—120目加14%的4%QF-1ChromosorbW.HP 100—120目的固定相机械混合时,对12种有机磷农药的难分离物质对,可提高其分离度或达到完全分离。  相似文献   

3.
建立超声波辅助萃取-气相色谱法同时分离测定蔬菜中5种有机磷农药残留量的:弓.法。实验结果表明,采用超声波加速提取有机磷农药残留,样品提取效果好,干扰物少,检测快速;在DB-1701色谱柱中,供试的5种有机磷农药分离良好;以FPD为检测器,选择性较好。方法的检出限为0.004-0.01μg/mL,5种农药在2个添加水平下的回收率为78.9%-105.9%,测定结果的相对标准偏差为2.6%-7.6%(n=6)。该方法具有测定有机磷农药种类多、快速等优点,能满足农药多残留分析的要求。  相似文献   

4.
有机溶剂对某些有机磷农药的NECC洗提影响的研究   总被引:1,自引:0,他引:1  
以有机磷农药甲基对硫磷、对硫磷等为被试验物质,探讨了在十二烷基硫酸钠、硼砂电解液中加入甲醇、乙醇、异丙醇、乙腈等有机溶剂对某些有机磷农药的毛细管胶束电动色谱分离的影响,并从电解液的物理化学性质和毛细管色谱动力学两方面阐明了其影响机理。  相似文献   

5.
设计了一种能够实现现场检测的有机磷农药残留掌上检测仪,其能够快速筛查有机磷农药污染的蔬菜,保障果蔬类农产品市场安全.基于酶抑制率法测量原理,以发光二极管(LED)为光源,设计双光电检测电路,由硅光电二极管进行信号采集,信号经单片机进行数据处理,实现了吸光度值和抑制率数字显示.与传统分光光度计相比,本实验设计的检测仪巧小轻便(127 mm×77 mm×35 mm)、方便携带,可实现现场零距离检测.实验表明,在乐果农药浓度为0.1~1.0?g/m L范围内,抑制率与乐果浓度呈良好线性,相关系数为0.9986,检出限为0.058?g/m L.将其应用于蔬菜中有机磷农药残留的测定,检测结果与国标方法有良好的相关性,能够对蔬菜中有机磷农药残留进行现场快速分析检测,具有实际的应用价值.  相似文献   

6.
有机溶剂对某些有机磷农药的MECC洗提影响的研究   总被引:2,自引:0,他引:2  
以有机磷农药甲基对硫磷、对硫磷等为被试验物质,探讨了在十二烷基硫酸钠、硼砂电解液中加入甲醇、乙醇、异丙醇、乙腈等有机溶剂对某些有机磷农药的毛细管胶束电动色谱分离的影响。并从电解液的物理化学性质和毛细管色谱动力学两方面阐明了其影响机理  相似文献   

7.
钱立立  何友昭  胡艳云 《分析化学》2006,34(11):1591-1594
用电动流动分析和酶抑制法测定池塘水中有机磷和氨基甲酸酯农药残留折合总量。电动流动分析系统由一台自制电渗泵和4个电磁切换阀组成,由计算机编程控制。酶抑制法用面粉酯酶,有机磷和氨基甲酸酯农药作酶抑制剂,底物的酶解产物与显色剂反应,用分光光度计在524 nm检测。有机磷和氨基甲酸酯农药的折合浓度对数线性范围为0.02~0.20 mg/L乐果,检出限为0.01 mg/L乐果,每小时可测24个样品。氨基甲酸酯在80℃完全水解,而有机磷部分水解,据此可判断农药类别。  相似文献   

8.
共振光散射比浊法测定有机磷农药残留量   总被引:7,自引:0,他引:7  
有机磷农药对人与动物的毒性作用较大,绝大多数有机磷农药都是剧毒的。因此,建立有效的检测有机磷农药残留的方法是非常重要的。目前检测有机磷农药的方法有:色谱法、光谱法、免疫法、生物传感器以及化学发光法等;农药速测卡也可以半定量或定量测定市售蔬菜中的有机磷农药残留。近年来共振光散射法(RLS)作为一种新的分析技术正得到越来越多的研究和应用。  相似文献   

9.
高分子多孔微球富集-HPLC法测定水体中的有机磷   总被引:1,自引:0,他引:1  
本文提出应用国产高分子多孔微球-GDX系列富集-反相高效液相色谱法测定废水中久效磷、乐果、甲基对硫磷三种有机磷农药分析方法。三种不同型号色谱固定相(GDX-102,GDX-301和GDX-501)对水体中ng/mL级久效磷、乐果和甲基对硫磷的富集效率分别达到85%、82%和93%以上。采用μ-BondapakC18作固定相,以60%甲醇水溶液作流动相,对三种有机磷农药的分离度可达到1.2以上。本法用于分析水体中有机磷农药,结果令人满意。  相似文献   

10.
水中重点有机磷农药的毛细管气相色谱法测定   总被引:11,自引:0,他引:11  
研究建立了气相色谱-火焰光度检测器(GC-FPD)法测定水中14种有机磷农药的分析方法,在选定的色谱条件下,14种有机磷农药在18min内得以很好的分离。在该方法下,14种有机磷农药的精密度良好,其中12种有机磷农药的加标回收率为92%-114.6%。  相似文献   

11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.  相似文献   

12.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

13.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

14.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

15.
The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.  相似文献   

16.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

17.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

18.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

19.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).  相似文献   

20.
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.  相似文献   

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