荧光分光光度法测定兽药中诺氟沙星

本文报道在ｐＨ２．６和β－环糊精存在下荧光分光光度法测定诺氟沙星，β－环糊精增强诺氟沙星荧光强度约２倍。其线性范围为７．８×１０－４μｇ／ｍＬ—１．５μｇ／ｍＬ，检测限为７．８×１０－４μｇ／ｍＬ，相对标准偏差为２．５％（ｎ＝５），方法用于兽药中诺氟沙星的测定，结果令人满意。     

毛细管电泳-电致化学发光测定诺氟沙星的研究

基于诺氟沙星对联吡啶钌在铂电极上的电致发光信号有增敏作用，与毛细管电泳结合，建立了一种测定诺氟沙星的电化学发光分析新方法。研究了工作电极电位、磷酸盐缓冲液浓度及其pH值、进样电压和进样时间等实验参数对诺氟沙星测定的影响。在优化的实验条件下，其浓度线性范围为0．02～10μmol／L；检出限（3σ）为0.0048μmol／L；峰面积的相对标准偏差为2．6％（1．0μmol／L，n=11）。本法可直接用于尿液中诺氟沙星（NFLX）含量的测定。回收率为92．7％～97．9％，结果满意。     

毛细管气相色谱法测定炼厂气中单体烃组分的含量

采用PLOT／Al2O3石英毛细管气相色谱柱和氢火焰离子化检测器，建立了炼厂气中单体烃组分含量测定的毛细管气相色谱法，当炼厂气中单体烃组分的含量大于或等于2．1％时，RSD≤0．95％，当炼厂气中单体烃组分的含量为0．5％－2．1％时，RSD为0．95％－10．0％，当炼厂气中单体烃组分的含量为0．2％－0．5％时，RSD为10．0％－25．0％，该方法对单体烃组分的测定结果与行业标准SH／T0230－92《液化石油气组成测定法》的测定结果基本一致。     

用氧化锌基准试剂作校正标准样品测定钨合金中的氧

RO－416型氧测定仪用氧化锌基准试剂校正后，用于测定钨合金中的氧，利用RO－416型氧测定仪在输入1．000g质量时测量范围是0．0％－4．5％的特点，分析质量为0．003－0．006g的氧化锌基准试剂，手动输入1．000g质量，测得氧含量在0．06％－0．12％，与钨合金粉末中的氧含量接近，用氧化锌基准试剂校正仪器是可行的。     

诺氟沙星离子选择性电极的研制和应用

研究了诺氟沙星选择电极的制备方法,将该电极应用于诺氟沙星胶囊制剂的测定。在ＮａＡｃ－ＨＡｃ（ｐＨ４．０）底液中,电极响应的线性范围为１．０×１０＾－４￣１．０×１０＾－２ｍｏｌ·Ｌ＾－１,七次测定的标示量百分含量的平均值为９４％,与药典法测定结果基本一致,相对标准偏差为１．０％。     

烃铵盐用于示波极谱滴定法测定诺氟沙星

本文报道了以烃铵盐为滴定剂，用交流示波极谱四苯硼钠（Ｎａ－ＴＰＢ）滴定法测定诺氟沙星（ＮＦＸ）的含量。应用于胶囊样品的测定，与药典法测得结果基本一致，最大相对误差≤０．５６％，最大ＲＳＤ为０．２９％，平均回收率为１００．６％。     

高效液相色谱法测定山生柳中酚苷类成分的含量

用高效液相色谱法测定山生柳中水杨苷、水杨酰水杨苷和木犀草素07－O－葡萄糖苷的含量，流动相为1．5％醋酸溶液－甲醇，Symmetry C18柱，柱温30℃，流速1．1mL/min，检测波长270nm，线性浓度范围分别为527．0－105．4um/mL,140-28.0ug/mL,81.0-16.2ug/mL，平均回收率是104．9％和103．6％，RSD分别为2．0％，0．3％和0．3％。     

2-羟基-3-羧基-5-磺酸基苯重氮氨基偶氮苯与汞的显色反应及其应用

研究了2－羟基－3－羧基－5－磺酸基苯重氮氨基偶氮苯（HCSDAA）与汞（Ⅱ）的显色反应。在乳化剂OP存在下和pH10．0～10．5的缓冲介质中，汞（Ⅱ）与HCSDAA形成1：2的红色络合物，其最大吸收波长是522nm，对比度为91nm，表观摩尔吸光系数为1．63×105L·mol－1·cm－1。汞（Ⅱ）在0～0．55mg／L范围内服从比尔定律。本方法操作简便，选择性较好，直接用于头发和废水的分析，6次测定的相对标准偏差分别为2．1％和27％，平均值与双硫腙法一致，回收率分别是94．8％～101．6％和98．7％～103．0％。     

离子色谱荧光检测法测定废水中痕量2-氨基联苯和4-氨基联苯

采用离子色谱荧光检测法测定废水中的2－氨基联苯（2－ADP）和4－氨基联苯（4－ADP），流动相为1．0mL/min的0．06mol/L NaCl,0.08mol/L HCl,40%(V/V)ACN，分离柱为Dinoex OmniPac PCX-500，该法具有良好的重现性和线性关系，2－ADP和4－ADP的回收率分别为98．5％－101．4％和102．2％－104．0％，检测限分别为0．006mg/L和0．10mg/L。     

漫反射FTIRS定量分析法测定诺氟沙星胶囊的含量

采用漫反射红外定量分析技术测定了诺氟沙星胶囊的含量，可排除辅料的影响，且吸光度与诺氟沙星的浓度呈良好的线性关系，平均回收率为98．23％，RSD为1．56％。方法简便、准确、可靠，可用于诺氟沙星胶囊的含量测定。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

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%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

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.     

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.