2,3—二氨基萘荧光分光光度法测定环境水样中的痕量亚硝酸盐

本文描述了用２，３－二氨基萘荧光分光光度法测定水样中亚硝酸盐的最佳测定条件，并测定了井水和湖水中的亚硝酸盐，测定样品的检出限为０．４μｇ／Ｌ，线性范围是１．０－１５００μｇ／Ｌ相对标准偏差为１．６％，加标回收率为９５％－１０６％。本法简便，快速，准确度高，共存离子干扰小，样品无须萃取步骤。     

氢化物发生电感耦合等离子体原子发射光谱法同时测定水和生物样品中…

研究了一种小型同心氢化物发生配置一个气液分离器后与多道ＩＣＰ－ＡＥＳ联用，同时测定水和生物样品中砷、铋、锑、硒的方法。检出限为砷０．４μｇ／Ｌ，铋０．５μｇ／Ｌ，锑１．４μｇ／Ｌ，硒０．５μｇ／Ｌ，相对标准偏差为砷２．７％，铋１．５％，锑２．７％，硒１．９％。用本法测定美国和国家标准物质中的氢化元素，结果满意。     

三波长K系数分光光度法同时测定痕量磷,砷,硅

１引言以碱性染料光度法同时测定磷、砷、硅已有报道，但需加入掩蔽剂或经还原－萃取等分离。本文用三波长Ｋ系数法原理，由计算机选出最佳波长组合，不经分离、掩蔽，于一份试液中同时测定痕量磷、砷、硅，其线性范围分别为４０．０～２４０．０μｇ／Ｌ、３２．０～１２０．０μｇ／Ｌ、３２．０～３２０．０μｄ／Ｌ。用于合成样品测定，结果令人满意。２实验部分２．１仪器与试剂７２２型光栅分光光度计。硅标准溶液：用高纯ＳｉＯ２（９９．９９％）以常法熔融配成ｐＨ约１．５的溶液，含硅０．１００ｇ／Ｌ；磷标准溶液：用ＫＨ２ＰＯ…     

火焰原子吸收光谱法间接测定非金属材料中氯

报道了火焰原子吸收光谱法（ＦＡＡＳ）间接测定非金属材料中氯的方法，采用ＡｇＣｌ沉淀，测定剩余Ａｇ~＋间接求出氯含量。方法的特征浓度为０．０１４ｍｇ／Ｌ（１％吸收），检出限为０．０３２ｍｇ／Ｌ（３），测定下限为０．１１ｍｇ／Ｌ，相对标准偏差（ＲＳＤ）为１．５％～１０％，样品加标准回收率在９１．４％－１０５％之间。     

钒（Ⅳ）—硫胺素荧光光度法的研究与应用

利用钒（Ⅳ）作为氧化剂将硫胺素氧化成硫胺荧,建立了一种测量痕量硫胺素的荧光分光光度法,并将该方法应用于药物中硫胺素的测定。该方法测定硫胺素的线性范围为０．８～２４０．０μｇ／Ｌ;检出限为０．４５μｇ／Ｌ;对于４０．０μｇ／Ｌ的硫胺素测定１０次,其相对标准偏差为１．５％。     

活性氧化铝富集火焰原子吸收法测定铬（Ⅲ）和铬（Ⅵ）

研究了内装活性氧化铝的微型柱流动注射富集分离火焰原子吸收光谱法（Ｆｌ－ＦＡＡＳ）测定水体中μｇ／Ｌ级的Ｃｒ（Ⅲ）、Ｃｒ（Ⅵ）。用０．２ｍｏｌ／Ｌ氨水将活性氧化铝转为碱式以吸附Ｃｒ（Ⅲ），１ｍｏｌ／Ｌ硝酸洗脱；用０．０１ｍｏｌ／Ｌ的硝酸将活性氧化铝转为酸式以吸附Ｃｒ（Ⅵ），０．２ｍｏｌ／Ｌ的氨水洗脱，洗脱液直接送到喷雾器中。进样３０ｓ，浓度富集２５倍。两种价态离子的校正曲线浓度范围在１～５０μｇ／Ｌ之间，检测限分别为０．６和０．７μｇ／Ｌ，样品分析速率为６０样／ｈ。研究了共存离子的干扰情况，实际水样中的加标回收率在８５％～１０５％之间。     

高效毛细管电泳－安培检测法测定牙膏中丙三醇和山梨醇

 用高效毛细管电泳－安培检测装置，以２００μｍ铜圆盘电极为工作电极，在碱性介质中，建立了分离测定丙三醇和山梨醇的最佳实验条件。结果表明：平均理论塔板数为２．４×１０５／ｍ，丙三醇和山梨醇的浓度检测限分别为３００μｇ／Ｌ和２００μｇ／Ｌ，线性范围接近３个数量级。在５．００～５０．０ｍｇ／Ｌ内，丙三醇和山梨醇的相关系数分别为０．９９９７和０．９９９５。样品测定结果与用高效液相色谱法测定的结果基本一致，回收率在９２％～１０４％之间。     

单柱离子色谱法同时测定磷酸中痕量钠（Ⅰ）和铁（Ⅲ）

以酒石酸－乙二胺为淋洗液的单柱离子色谱法同时测定磷酸中痕量钠（Ⅰ）和铁（Ⅲ）。淋洗液最佳浓度为４．０ｍｍｏｌ．Ｌ￣（－１）、酒石酸／１．０ｍ　ｍｏｌ·Ｌ￣（－１）乙二胺。最低检测限为Ｎａ￣＋０．０５μｇ／ｍＬ、　Ｆｅ３＋　０．４５μｇ／ｍＬ。电导检测灵敏度为２．０μｇ／ｃｍ。线性范围Ｎａ￣＋、Ｆｅ３＋０．２～１．５×１０３μｇ／ｍＬ、２．５～１．０×１０３μｇ／ｍＬ。相对平均偏差Ｎａ￣＋为２．０３％、Ｆｅ３＋为０．８３％。平均回收率Ｎａ￣＋为９８．２６％、Ｆｅ３＋为９７．６２％。本法简便、快速、准确、选择性好。     

高效毛细管电泳－安培检测法测定牙膏中丙三醇和山梨醇

用高效毛细管电泳－安培检测装置，以２００μｍ铜圆盘电极为工作电极，在碱性介质中，建立了分离测定丙三醇和山梨醇的最佳实验条件。结果表明：平均理论塔板数为２．４×１０５／ｍ，丙三醇和山梨醇的浓度检测限分别为３００μｇ／Ｌ和２００μｇ／Ｌ，线性范围接近３个数量级。在５．００～５０．０ｍｇ／Ｌ内，丙三醇和山梨醇的相关系数分别为０．９９９７和０．９９９５。样品测定结果与用高效液相色谱法测定的结果基本一致，回收率在９２％～１０４％之间     

反相流动注射催化光度法测定痕量锰

本文基于在邻菲罗啉活化下，锰（Ⅱ）对高碘酸钾氧化罗丹明Ｂ褪色的催化作用，建立了痕量锰的反相流动注射分析方法。方法的线性范围为０－５０μｇ／Ｌ，检测下限为０．７μｇ／Ｌ锰（Ⅱ）。对２０μｇ／Ｌ锰（Ⅱ）测定九次的相对标准偏差为１．８％，进样频率不少于６０次／ｈ。方法应用于水样和标准镁合金样品分析，结果满意。     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

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.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

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%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

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.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

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.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

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.     

正丁胺对激光染料荧光谱影响的研究

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.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

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 Cu^I 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).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(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.