共查询到20条相似文献,搜索用时 62 毫秒
1.
气相色谱法同时测定糙米中6种取代苯类及酰胺类农药残留 总被引:3,自引:0,他引:3
建立了气相色谱法同时测定糙米中二甲戊灵、丙草胺等6种农药残留量的方法。采用BP225大口径毛细管柱和氮磷检测器,外标法定量。样品加标回收率为80.4%~103.0%,相对标准偏差为2.9%~10.2%。各种农药的最低检出限分别为:戊草丹、二甲戊灵0.01 mg/kg ;丙草胺、氟酰胺、灭锈胺与苯噻酰草胺0.02 mg/kg 。该方法操作简便、快速、灵敏、准确,适于批量样品的测定。 相似文献
2.
高效氯氟氰菊酯在田间环境中的消解行为研究 总被引:2,自引:0,他引:2
本文选择了我国从吉林到海南5个重要的农业生产区,对常用杀虫剂高效氯氟氰菊酯在玉米、大豆、甘蓝、土豆、苹果等农作物上的降解规律进行了研究,并对其在这几种作物上的使用安全性进行了评价.研究包括:建立了基于气相色谱-电子捕获检测方法的高效氯氟氰菊酯的检测方法;在对高效氯氟氰菊酯在土壤中的降解规律进行研究,发现在施药后的前五天,消解速率比较快,并且农药在土壤中的消解行为在统计意义上是没有显著差别.高效氯氟氰菊酯在五地土壤中的半衰期在1.56到5.30天的范围内;在对作物上农药残留的消解过程的研究中发现,其在苹果上的降解速率明显低于其他作物,其半衰期在北京为10.3天,安徽为17.7天.北京的其他作物中高效氯氟氰菊酯的半衰期在1.32至2.74天之间,安徽的其他作物中在2.07到3.80天之间.高效氯氟氰菊酯在作物中的传递性比较差,在直接接触农药的甘蓝和苹果中能够检测到农药残留,而在不直接接触喷施农药的玉米、大豆和土豆上检测不到残留. 相似文献
3.
4.
建立快速、准确测定果蔬中5种拟除虫菊酯类农药残留量的方法。采用漩涡振荡提取农药残留,固相萃取柱净化,毛细管柱气相色谱法-μECD检测器测定。该法可同时分离检测5种拟除虫菊酯类农药残留,检出限为0.001~0.005μg/mL。拟除虫菊酯类农药残留量在0.01~1μg/mL范围内与色谱峰高线性关系良好,相关系数大于0.9998。测定结果的相对标准偏差为4.8%~10.5%(n=6),回收率为89.9%~105.0%。 相似文献
5.
QuEChERS净化GC/ECD测定茶叶与土壤中噻虫嗪、虫螨腈及高效氯氟氰菊酯残留 总被引:4,自引:0,他引:4
采用QuEChERS方法净化,建立了GC/ECD法同时检测茶叶和土壤中噻虫嗪、虫螨腈和高效氯氟氰菊酯残留的分析方法。样品经水浸润后,乙腈提取,适量PSA、GCB和Florisil混合填料净化提取液,GC/ECD检测。噻虫嗪、虫螨腈和高效氯氟氰菊酯的响应分别在0.50~400、0.20~100、0.40~200μg/L质量浓度范围内线性良好,相关系数r均大于0.99,检出限分别为0.25、0.05、0.10μg/L。茶叶和土壤样品中,噻虫嗪、虫螨腈和高效氯氟氰菊酯的平均加标回收率为62%~108%,相对标准偏差(RSDs)不大于15.8%,方法的定量下限(LOQs)均不大于10μg/kg。方法简便、快速,能够满足茶叶和土壤中上述3种不同极性农药残留同时检测的需要。采用该方法测定了3种农药在茶园茶叶和土壤中的残留量,结果满意。 相似文献
6.
毛细管气相色谱法测定12种农药的有效成分 总被引:4,自引:0,他引:4
建立了毛细管气相色谱法测定速克灵、戊唑醇等 12种农药中有效成分的方法。采用SE 3 0大口径毛细管柱和火焰离子化检测器 (FID) ,内标法定量 ,气相色谱 /质谱法定性确证 ,样品加标的平均回收率为 99 2 0 %~10 2 4 4 % ,相对标准偏差为 0 0 7%~ 5 4 9%。该方法简单快速 ,结果准确 ,可作为测定单样、复配样农药或同时测定多种农药有效成分的通用方法 相似文献
7.
8.
β-氯代-取代烯丙醇(含不饱和脂肪醇、脂环醇和氰醇)与具有较强生物活性的菊酸和氰戊菊酸为酸的部分,经酰氯化后在有机碱存在下酰化成酯,合成了20个新化合物.对化合物的分子结构进行了表征,初步生物活性试验表明部分化合物具有较好的杀虫活性 相似文献
9.
《理化检验(化学分册)》2010,(10)
提出了用气相色谱-火焰光度检测器(GC-FPD)测定大豆中24种有机磷农药残留量的方法。采用乙腈匀质提取大豆试样中残留的有机磷农药,提取液依次经C18固相萃取柱、活性炭固相萃取柱和硅胶固相萃取柱净化。淋出液用DB-1701石英毛细管柱进行分离,GC-FPD检测,外标法定量。方法的检出限在0.005~0.010 mg.kg-1之间。所测24种农药的标准加入回收率在60.7%~115.6%之间,相对标准偏差(n=6)为1.7%~11.1%。 相似文献
10.
11.
Uroš Grošelj Mojca Žorž Amalija Golobič Branko Stanovnik Jurij Svete 《Tetrahedron》2013,69(52):11092-11108
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
12.
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
13.
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
14.
Shashikant U. Dighe Surya K. Samanta Shivalinga Kolle Sanjay Batra 《Tetrahedron》2017,73(17):2455-2467
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
15.
In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates. 相似文献
16.
Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described. 相似文献
17.
用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在. 相似文献
18.
19.
Jona Mirnik Eva Pušavec Kirar Sebastijan Ričko Uroš Grošelj Amalija Golobič Franc Požgan Bogdan Štefane Jurij Svete 《Tetrahedron》2017,73(24):3329-3337
A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu0 as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than CuI in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT). 相似文献
20.
George E. Magoulas Thomas Garnelis Constantinos M. Athanassopoulos Dionissios Papaioannou George Mattheolabakis Konstantinos Avgoustakis Dimitra Hadjipavlou-Litina 《Tetrahedron》2012,68(35):7041-7049
(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C60, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine. 相似文献