零流电位法对4-氨基联苯的检测

以铅笔芯电极(PGE)为工作电极,铂电极为对电极,饱和甘汞电极为参比电极,在含4. 0×10-3mol/L丙烯酸、1. 0×10-3mol/L 4-氨基联苯(4-ABP)的磷酸盐缓冲溶液(PBS,p H 7. 17)中,采用循环伏安法以0. 1 V·s-1在-1. 6～1. 6 V电位范围循环扫描16圈,经超声洗脱6 min后制得4-氨基联苯印迹聚合物修饰电极(4-ABP-MIP/PGE)。零流电位法下,在4-ABP浓度0. 005～50μmol/L范围内,4-ABP-MIP/PGE的零流电位EZCP与4-ABP浓度的对数呈线性关系,检出限为1. 07 nmol/L。将该传感器用于实际样品中4-ABP的检测,平均回收率为96. 0%～102%。     

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％。     

高效液相色谱法测定环境水中痕量4,4′-二氨基联苯、4-硝基酚和苯酚

采用ＰｈｅｎｏｍｅｎｅｘＳｐｈｅｒｅｘＣ１８色谱柱,以含５０ｍｍｏｌ／Ｌ乙酸－乙酸钠缓冲溶液（ｐＨ６．０）的Ｖ（乙腈）∶Ｖ（乙醚）∶Ｖ（水）＝１２∶１０∶７８混合溶液为流动相,用分光光度法检测,检测波长为２７５ｎｍ,在１６ｍｉｎ内实现了４,４′－二氨基联苯、４－硝基酚和苯酚的同时分离测定。检测限分别为０．１４,０．１９和０．０８ｎｇ。标准回收率分别为９８．８５％,９８．１５％和９８．１０％。方法灵敏度高,用于环境水样分析时结果令人满意。     

4 氨基4′ 氰基联苯的合成

４氨基４′氰基联苯,不仅是制备烷氧基联苯的原料,而且可以制备高正介电各向异性液晶及系列酯类液晶材料．但通常要经过酰化、氧化、酰氯化、氨解、脱水、硝化和还原［１］等多步反应,步骤长、收率低,本文用联苯为原料,经过硝化、碘代、氰代和还原反应合成４氨基４′氰基联苯．反应步骤及时间比原路线减少近一半,而且反应条件温和,收率高．联苯（ＣＰ,上海化学试剂一厂）;Ｎ,Ｎ二甲基甲酰胺（ＡＲ,临平化工试剂厂）;氯仿（ＡＲ,沈阳试剂一厂）;亚硫酸氢钠（ＡＲ,大连辽南化学品厂）;碘酸（ＡＲ,北京化工厂）…     

4-氨基-4'-氰基联苯的合成

氨基氰基联苯;4-氨基-4'-氰基联苯的合成     

水杨醛缩5,7-二溴-8-氨基喹啉荧光光度法 测定粮食中的痕量锌

合成了新型息夫碱类试剂水杨醛5,7－二溴－8－氨基喹啉,建立了该试剂荧光光度法测定痕量锌（Ⅱ）的新体系,在pH5-6范围内,50％（V／V）乙醇的溶液中,试剂与锌（Ⅱ）的络事比为2：1,λem=400nm/475nm,线笥范围为0－288μg/L,检出限为1.4μg/L,考察了共存离子的影响,已应用于粮食中痕量锌的测定。     

2-(3,5-二氯-2-吡啶偶氮)-5-二甲氨基苯胺激光热透镜光谱法测定钯

基于2－（3，5－二氯－2－吡啶偶氮）－5－二甲氨基苯胺（3，5-diCl-PADMA)与钯的显色反应，以激光热透镜头谱法测定了微量钯。实验表明，在强酸性介质中，Pd^2 与3，5－diCL-PADMA室温显色形成稳定的蓝色配合物，最大吸收波长位于623nm处，与所用激光器输出激光波长匹配较好，从而建立了激光热透镜光谱法测定钯的新方法。钯浓度分别在0．005－0．04mg/L和0．03－0．025mg/L范围内呈线性关系，方法灵敏度高，选择性、重现性好，用于样品测定，结果满意。     

超高效液相色谱-串联质谱法测定化妆品还原液内的4-氨基联苯

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)检测化妆品还原液中4-氨基联苯的方法.化妆品试样经过连二亚硫酸钠化学还原后,离心、PCX固相萃取小柱提取富集、净化,并经氨化甲醇洗脱、氮吹至近干,定容后通过UPLC-MS/MS仪检测,分离柱为Waters Acquity BEH C18柱;流动相为0.3％乙腈-甲酸水溶液;流速0.5mL/min.5种不同基质中4-氨基联苯在5～250 ng/mL浓度范围内呈良好的线性关系,线性回归系数r2均大于0.999,检测限均为1 ng/mL.5种不同基质中4-氨基联苯的回收率为80.9％～92.6％,相对标准偏差(RSD)为0.51％～3.76％(n=3).     

改性HZSM－5催化剂上4－甲基联苯与甲醇的甲基化反应性能

 采用浸渍法制备了一系列金属氧化物（MgO，CaO，SrO，BaO，ZnO，La2O3和CeO2）改性的HZSM－5催化剂，以4－甲基联苯与甲醇的烷基化为探针反应，在固定床反应器上考察了其催化性能．结果表明，在MgO改性的HZSM－5催化剂上，目的产物4，4′－二甲基联苯的选择性最高，可达80％，而在未改性的HZSM－5上仅为13％．金属氧化物改性对4，4′－二甲基联苯的选择性均有提高，其大小顺序为：MgO＞SrO≈ZnO≈CaO≈La2O3＞BaO＞CeO2．另外，还详细研究了MgO改性条件（如MgO浸渍量，改性剂的阴离子种类，改性方法）的影响．结果表明，MgO浸渍量为5．6％时较为合适．     

高效液相色谱法测定吡啶、2-氨基吡啶、2-甲基吡啶和2-吡啶甲酸

建立了以磷酸氢二钾-磷酸盐缓冲溶液中添加甲醇为流动相，以反相高效液相色谱同时测定吡啶、2-氨基吡啶、2-甲基吡啶和2-吡啶甲酸的新方法。在流动相为甲醇-0．1mol／L磷酸氢二钾和磷酸缓冲溶液、pH为6．0的最佳条件下，吡啶、2-氨基吡啶、2-甲基吡啶和2-吡啶甲酸的加标回收率分别为98．2％～102．1％、99．1％～101．3％、97．8％～100．7％和99．1％～102．4％；线性范围分别为20～980、18～913、19～943和18～902mg／L；检出限分别为2．0、1．8、1．9和1．8mg／L。本法可同时测定电氧化2一甲基吡啶过程中电解液。     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

化学计量中不确定度评定研究进展

测量不确定度是表征合理地赋予被测量之值的分散性的参数。本文针对化学计量不确定度评定基础模型仅适用于线性模型、概率分布为正态分布或缩放位移t分布等局限,介绍了近年来不确定度评定的研究热点:蒙特卡罗方法(Monte Carlo Method,MCM),不确定度评定的来源、评定概念、评估方法及其发展过程,扩大了测量不确定度评定与表示的适用范围。