荧光光谱法研究利血平的氧化作用及其分析应用

利血平自身有弱荧光,氧化后可形成较强荧光物质。本文系统地研究了稀ＨＮＯ３对利血平的氧化作用,提出了高灵敏度测定利血平含量的荧光光度分析新方法。结果表明,荧光强度和利血平的浓度在０．０２－０．４μｇ／ｍＬ范围内呈良好的线性关系,方法的检出限为０．００２μｇ／ｍＬ（６．７３＊１０＾－９ｍｏｌ／Ｌ）。该法简便,快速、灵敏度高,用于注射液中利血平含量的测定,结果令人满意。     

流动注射化学发光法测定利血平

研究了利血平在酸性条件下与高锰酸钾和过氧化氢产生化学发光的行为，建立了流动注射化学发光测定利血平的新方法。利血平的浓度在１．０×１０＾－６￣８．０×１０＾－５ｈ／ｍＬ范围内与化学发光强度呈良好的线性关系；检出限为３×１０＾－７ｇ／ｍＬ。对６×１０＾－６ｇ／ｍＬ利血平进行１１次平行测定，得方法的相对标准偏差为１．３％。方法用于药剂中利血平含量测定，结果与药典标准方法测得值一致。     

流动注射停流荧光动力学分析法测定痕量铁的研究

利用自行组装的流动注射停流荧光动力学分析装置，研究了铁（Ⅲ）与３，５－二溴水杨基荧光酮的荧光动力学反应性质，提出了一种快速，简便，精确地测定痕量铁的新方法，其线性范围为０．０２０－０．２５０μｇ／ｍＬ，线性相关系数为０．９９９，检测限为１０ｎｇ／ｍＬ，以０．２００μｇ／ｍＬ的铁（Ⅲ）作精度试验，Ｒ．Ｓ．Ｄ％＝２．１％（ｎ＝１１）。该方法已成功地用于铝合金及桃树叶中痕量铁的测定，结果分别与ＩＣＰ法和     

二溴羟基苯基荧光酮荧光猝灭法测定Br^—

本文报道了以二溴羟基苯基荧光酮（ＤＢＨ－ＰＦ）为指示剂，在阳离子表活性剂ＣＰＣ存在下荧光猝灭间接测定Ｂｒ＾－的新方法。在０．６ｍｏｌ／ＬＨ２ＳＯ４介质中，Ｂｒ＾－和ＢｒＯ３＾－反应生成Ｂｒ２，Ｂｒ２与ＤＢＨ－ＰＦ（λｅｍ＝５２０ｎｍ）生成红色化合物，使体荧光猝灭。Ｂｒ＾－含量在０．２５－６．２５μｇ／２５ｍＬ范围内有良好的线性关系，检测限为０．２５μｇ／２５ｍＬ。该法灵敏度高，选择性好，用于合成海     

新试剂5－氟偶氮胂Ⅰ荧光法测定铝的研究

本文报道了新试剂５－氟偶氮胂Ⅰ（５－ＦＡｓＡ－Ⅰ）的合成方法，研究了荧光光度法测定铝的反应条件。Ａｌ（Ⅲ）与试剂在ｐＨ５．６０ＨＡｃ－ＮａＡｃ缓冲介质中形成１＋１红色配合物并呈现荧光，λｅｘ／λｅｍ＝３４８．６／３９１．４ｎｍ，线性范围为０～０．２μｇ／ｍＬ，检测限为３．０ｎｇ／ｍＬ。用于分析茶叶样品中的铝，结果满意。     

表面活性剂增敏铍试剂Ⅱ荧光法测定痕量锰

在碱性条件下，Ｍｎ（Ⅱ）与铍试剂Ⅱ形成１；２的荧光络合物，其荧光峰为λｅｘ＝λｅｍ＝３６７／４６７（ｎｍ），表面活性剂十二烷基苯磺酸钠对体系具有强烈增敏作用，基于此建立了痕量锰的测定方法。本文研究了测定的最佳条件，即０．０１％铍试剂Ⅱ４．０ｍＬ，０．１ｍｏｌ／ＬＮａＯＨ６．０ｍＬ，１％ＳＤＢＳ ４．０ｍＬ，反应温度为９０℃，时间１０ｍｉｎ，线性范围为０－１６０μｇ／Ｌ，回归方程Ｘ（μｇ／Ｌ）＝２．     

流动注射化学发光法测定甲氨蝶呤

研究了甲醛增强高锰酸钾与甲氨蝶呤的化学发光反应，由此建立了一种测定甲氨蝶呤的流动性注射化学发光分析法，方法的检出限为３．４×１０＾－９ｇ／ｍＬ，相对标准偏差为１．１％（２．０×１０＾－６ｇ／ｍＬ甲氨蝶呤，ｎ＝１１）线性范围为１．０×１０＾－８～１．０×１０＾－５ｇ／ｍＬ。该法已用于甲氨蝶呤针剂及片剂中甲氨蝶呤含量的测定。     

以氟苯酚—H2O2—HRP体系酶联荧光免疫分析研究：Ⅲ.F^—Al酸性铬蓝…

建立了一种检测人血清中乙肝Ｅ抗原的新荧光光度法，通过酶促反应，对氟苯酚＋Ｈ２Ｏ２→＾ＨＲＰ苯酚＋Ｆ＾－＋Ｈ２Ｏ与Ａｌ－酸性铬蓝Ｋ荧光体系相偶合，测定辣根过氧化物酶（ＨＲＰ）及其标记物，测定ＨＲＰ的线性范围为０．１９～３１ｍＵ／ｍＬ，检出限为０．０４ｍＵ／ｍＬ。     

水杨醛缩7—氨基—8—羟基喹啉—5—磺酸催化荧光法测定痕量钒（V）

水杨醛缩－７－氨基－８－羟基喹啉－５－磺酸（简称Ｓ７Ｎ８Ｑ５Ｓ）在酸性介质中分解，产物呈现荧光，Ｖ（Ⅴ）对该反应具有催化作用，本文建立了催化荧光法测定痕量钒的新方法。体系在ＰＨ＝２的柠檬酸钠－盐酸缓冲溶液中，λｅｘ／λｅｍ＝３４２／４９９（ｎｍ）。测定Ｖ（Ⅴ）的最佳反应条件为０．０４％Ｓ７Ｎ８Ｑ５Ｓ５．０ｍＬ，５％ＫＢｒＯ３５．０ｍＬ，缓冲溶液５．０ｍＬ，９０℃加热５ｍｉｎ。Ｖ（Ⅴ）含量在１２．０     

烟草中Fe,Co一阶导数分光光度法同时测定的研究

本文研究了在ｐＨ４．０时，ｍｅｓｏ－四（４－磺酸基苯基）卟啉与铁、钴同时络合显色的反应条件以及一阶导数光谱行为。此体系一阶导数的灵敏度比零阶导数灵敏度高。Ｆｅ￣（３＋）～０．１８μｇ／ｍＬ、Ｃｏ￣（２＋）０～０．２４μｇ／ｍｌ，范围内符合比耳定律；检测限为：Ｆｅ￣（３＋）＝０．４８ｎｇ／ｍＬ，Ｃｏ￣（２＋）＝０．２ｎｇ／ｍＬ。回收率为：Ｆｅ９８．５％～１００．８％，Ｃｏ９９．２％～１０１．３％。此方法用于烟草中痕量Ｆｅ、Ｃｏ测定，与ＡＡＳ值相比较，结果令人满意。     

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。