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以铕( Eu3+)-邻苯二甲酸二丙烯酯为荧光探针,建立了一种快速、灵敏测定水中痕量甲萘威的方法。通过高分辨质谱研究铕与邻苯二甲酸二丙烯酯及甲萘威间的络合作用,比较甲萘威与荧光探针结合前后的荧光光谱变化,考察溶液pH值、干扰物质对配合物荧光强度的影响。实验结果表明,Eu3+与邻苯二甲酸二丙烯酯形成稳定配位数为2的络合物,甲萘威能与该探针形成多元配位复合物,且甲萘威的结合能显著增强Eu3+-邻苯二甲酸二丙烯酯探针的荧光发光效率。在pH 9.0条件下,采用245/615 nm作为激发/发射波长,在6.25伊10-8~2.50伊10-6 mol/L浓度范围内溶液的荧光强度与甲萘威的浓度呈良好线性关系,线性相关系数为0.9968,检出限为9.6伊10-9 mol/L。水样经乙腈提取后,采用铕(Eu3+)-邻苯二甲酸二丙烯酯荧光探针进行测定,方法的回收率在91.8%~94.5%之间,相对标准偏差在6.1%以内。本方法适用于环境水样中甲萘威的快速测定。 相似文献
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建立了超高效液相色谱-串联质谱(UPLC-MS/MS)同时测定环境水体中呋喃丹、莠去津、甲萘威和6种邻苯二甲酸酯的分析方法。采用Pak C18固相萃取小柱对样品进行富集和净化,甲醇-水为流动相梯度洗脱,以BEH C18柱分离,在串联质谱的多反应监测模式(MRM)下检测,外标法定量。结果表明,在优化实验条件下,9种目标化合物在0.5~20.0μg/L范围内线性关系良好,相关系数均大于0.998,方法检出限(LOD)和方法定量下限(LOQ)分别为0.05~0.12μg/L和0.2~0.3μg/L,回收率为86.0%~96.5%,相对标准偏差(RSD)小于5%。方法快速准确、回收率高,适用于环境水体中呋喃丹、莠去津、甲萘威及6种邻苯二甲酸酯的测定。 相似文献
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固相萃取-加压毛细管电色谱法测定水体中8种农药残留 总被引:1,自引:0,他引:1
《分析科学学报》2015,(4)
采用固相萃取-反相加压毛细管电色谱-紫外检测技术,建立了水体中乐果、敌敌畏、克百威、甲萘威、莠去津、甲基对硫磷、马拉硫磷、百菌清8种农药残留的同时检测方法。在最佳条件下,8种目标农药的线性范围分别为:3.4~100μg/mL、8.1~120μg/mL、1.2~50μg/mL、0.2~50μg/mL、0.1~50μg/mL、3.7~100μg/mL、11.2~150μg/mL、2.1~100μg/mL,相关系数为0.9961~0.9997;检出限(S/N=3)在0.03~3.7μg/mL之间,加标回收率在71.0%~114.1%范围,相对标准偏差(RSD)为1.1%~9.8%。该方法简单、可靠、适用于水中多种农药残留的同时分析测定。 相似文献
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基于噁喹酸对锰掺杂硫化锌量子点的荧光猝灭作用,建立了一种噁喹酸荧光共振能量转移检测方法。噁喹酸对量子点的荧光猝灭是由于生成了新的复合物而造成的静态猝灭,二者相互作用过程中焓变ΔH<0,熵变ΔS<0,分子间作用力为氢键或范德华力。在0~65μg/L线性范围内,噁喹酸质量浓度与量子点荧光抑制率呈现良好的线性关系(R2=0.9911),检出限为0.53μg/L。分别在5μg/L和25μg/L 2个浓度进行加标回收,平均加标回收率为92.2%~96.8%,相对标准偏差为0.6%~2.5%。该方法可应用于水环境中喹啉酮类杀菌剂噁喹酸的快速测定。 相似文献
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An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions. 相似文献
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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
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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
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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
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An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction. 相似文献
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The Diels-Alder reactivity of 1,2-heteroborines (H4C4B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed. 相似文献
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Xi-Liu YunWen-Ying Bi Jian-Hui HuangYu Liu Daisy Zhang-NegrerieYun-Fei Du Kang Zhao 《Tetrahedron letters》2012,53(38):5076-5080
A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd2(dba)3-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring. 相似文献
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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
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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
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Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles. 相似文献