多阴离子和铜磷酸盐为基元的杂化材料的合成、结构和性质

本文采用水热法合成了一个新的金属有机-无机杂化化合物 [Cu₄(phen)₄(HPO₄)₂(H₂O)₂(OH)₂][HPMo₁₂O₄₀]·H₂O (1) ( phen=邻菲咯啉)。通过元素分析、红外光谱、热重分析、X-射线单晶衍射对其进行了结构表征。化合物1是由四核铜磷酸盐、Keggin阴离子和晶格水分子组成。四核铜磷酸盐和多阴离子之间通过弱的M…O相互作用形成二维结构(M=Cu, Mo), 该二维结构通过氢键和π-π相互作用形成三维超分子框架,还对化合物1的电化学和电催化性质进行了研究。     

An efficient Biginelli one-pot synthesis of new benzoxazole-substituted dihydropyrimidinones and thiones catalysed by trifluoro acetic acid under solvent-free conditions

An efficient synthesis of benzoxazole-substituted 3,4-dihydropyrimidinones(DHPMs) using trifluoro acetic acid as the catalyst for the first time from an aldehyde,β-keto ester and benzoxazole-substituted urea/thiourea under solvent-free conditions is described.Compared to the classical Biginelli reaction conditions,this new method consistently has the advantage of excellent yields(80-91%) and short reaction time(40-130 min) at reflux temperature.     

谱图相似度分析结合保留指数对单萜烯同分异构体的GC—MS定性分析

运用欧氏距离的最短距离聚类分析法,对在质谱数据库NIST02.L检索到的37种单萜烯同分异构体的93张质谱图进行了分类.结果显示,单萜烯被分成5类,大部分单萜烯聚到1类,包括30种单萜烯的77张质谱图.但部分谱图很近似,仅用传统的质谱库匹配鉴定其结构存在一定的困难.采用改进的谱图相似度分析结合保留指数实现了有效定性,并将该方法用于实际样品的定性分析.     

霉菌甲醛脱氢酶活性的分光光度法测定

甲醛在甲醛脱氢酶的作用下与辅酶Ⅰ(NAD)形成甲酸或甲酸盐,根据其生成的还原型辅酶Ⅰ二钠盐(β-NADH)的量与吸光度成正比,建立了测定3株霉菌在3个处理方法中的甲醛脱氢酶活性的分光光度法.以绿色木霉(Trichoderma viride)、爪哇青霉(Penicillium javanicum)、黄曲霉(Aspergillus flavus) 3株甲醛降解霉菌为材料,通过全温振荡培养,pH 7.5的0.05 mol/L 的磷酸钾缓冲溶液洗涤、离心、提取,并在37 ℃、pH 7.5、340 nm处测定甲醛脱氢酶活性.结果表明:细胞破碎处理1(600 W,工作5 s、间歇7 s,60次)破碎细胞不完全,只能测得部分酶活性;细胞破碎处理3(800 W,工作5 s、间歇7 s,60次)破碎细胞完全,但破坏了部分酶活性;细胞破碎处理2(700 W,工作5 s、间歇7 s,60次)能很好地破碎细胞且对酶活性的破坏最少,测得最高酶活性.     

毛细管电泳-联吡啶钌电化学发光法对血浆中丁卡因与普鲁卡因的同时测定

建立了毛细管电泳-电致化学发光同时测定丁卡因和普鲁卡因的新方法.考察了毛细管电泳流动相和检测池中磷酸盐缓冲液pH和浓度、进样时间和电压、分离电压和检测电位等对丁卡因和普鲁卡因的分离以及联吡啶钌电致化学发光检测的影响.基于循环伏安法考察了丁卡因和普鲁卡因的电化学行为与发光机理.在优化的实验条件下,丁卡因和普鲁卡因的标准曲线分别在6.6 ～265.6 μmol/L和0.7 ～219.0 μmol/L范围内呈良好的线性,检出限(S/N=3)分别为1.9 μmol/L和0.2 μmol/L.对23 μmol/L丁卡因和15 μmol/L普鲁卡因的标准溶液连续测定5次,迁移时间的相对标准偏差(RSD)分别为0.13%、0.16%,电化学法发光强度的RSD分别为3.7%和4.9%.该方法已成功用于血浆中丁卡因和普鲁卡因的同时检测,平均回收率均为94%,相对标准偏差低于4%.     

致癌性多环芳烃萘、蒽、芘的分析方法比较

利用薄层色谱（TLC）、紫外光谱（UV）、反相高效液相色谱（RPHPLC）对多环芳烃（PAHs）萘、蒽、芘的分析方法进行了研究。TLC中使用环己烷：氯仿（5：4,V／V）作为展开剂时,三者的R,值分别为0．78、0．65和0．72;用UV法在溶液中测定了三者的最大吸收波长分别为303、380、338nm;当流动相为甲醇：水（9：1,V／V）时三者在RP—HPLC中的保留时间为4．179、5．190、6．178min,5次重复RSD分别为1．1％、1．8％、0．91％,并用于实际水样中萘、蒽、芘的分析。     

HPLC法测定鸡精中谷氨酸钠的含量

以邻苯二甲醛与谷氨酸钠中的氨基进行柱前在线衍生化反应,采用C18色谱柱分离、荧光检测器（激发340nm,发射450nm）进行测定,建立了柱前衍生反相高效液相色谱测定鸡精中谷氨酸钠含量的方法。该方法相对标准偏差为0．69％,加标回收率为99．1％～101％,在0．10~50．0mg／L范围内,谷氨酸钠的峰面积和浓度之间的相关系数为0．9999,保留时间和峰面积的相对标准偏差分别为1．22％和0．71％,鸡精中谷氨酸钠定量下限为0．2μg／g。     

有序介孔硅片粒子表面的修饰及其表征

采用溶胶-凝胶的方法制备了粒径在50~300nm,具有正六边形的介孔二氧化硅片,用1,6-己二异氰酸酯(hexamethylene diisocyanate,HDI)对有序介孔硅片粒子表面进行有机化修饰,使其表面接枝能够参与反应的N=C=O活性基团。用FTIR、热重分析、TEM等分析方法对修饰后的有序介孔硅片粒子进行了表征,以确定HDI接在了有序介孔硅片粒子的表面。     

Structural determination of glucosylceramides isolated from marine sponge by fast atom bombardment collision‐induced dissociation linked scan at constant B/E

Five glucosylceramides (GlcCers) were isolated by reversed phase high‐performance liquid chromatography from the MeOH extracts of a marine sponge, Haliclona (Reniera) sp., collected from the coast of Ulleung Island, Korea, and analyzed by fast atom bombardment mass spectrometry (FAB–MS) in positive‐ion mode. FAB‐mass spectra of these compounds included protonated molecules [M + H]⁺ and abundant sodiated molecules [M + Na]⁺ from a mixture of m‐NBA and NaI. The structures of these GlcCers, which were similar, were elucidated by FAB‐linked scan at constant B/E. To find diagnostic ions for their characterization, the GlcCers were analyzed by collision‐induced dissociation (CID) linked scan at constant B/E. The CID‐linked scan at constant B/E of [M + H]⁺ and [M + Na]⁺ precursor ions resulted in the formation of numerous characteristic product ions via a series of dissociative processes. The product ions formed by charge‐remote fragmentation provided important information for the characterization of the fatty N‐acyl chain moiety and the sphingoid base, commonly referred to as the long‐chain base. The product ions at m/z 203 and 502 were diagnostic for the presence of a sodiated sugar ring and β‐D ‐glucosylsphinganine, respectively. For further confirmation of the structure of the fatty N‐acyl chain moiety in each GlcCer, fatty acid methyl esters were obtained from the five GlcCers by methanolysis and analyzed by FAB–MS in positive‐ion mode. On the basis of these dissociation patterns, the structures of the five GlcCers from marine sponge were elucidated. In addition, the accurate mass measurement was performed to obtain the elemental composition of the GlcCers isolated from marine sponge. Copyright © 2009 John Wiley & Sons, Ltd.     

Selective Homologation Routes to 2,2,3‐Trimethylbutane on Solid Acids

Sailing the seven ‘C's : 2,2,3‐Trimethylbutane (triptane) selectively forms from dimethyl ether at low temperatures on acid zeolites. Selective methylation at less‐substituted carbons, relative rates of methylation to hydrogen transfer as a function of chain size, slow skeletal isomerization, and β‐scission cracking of triptyl chains and their precursors are intrinsic properties of carbenium ions and account for the remarkable triptane selectivities within C₇ .