聚甲基蓝修饰电极的制备及对多巴胺的测定

研究了聚甲基蓝修饰电极的制备及其多巴胺在聚甲基蓝修饰电极上的循环伏安特性,建立了循环伏安法测定多巴胺的新方法。在pH7.0磷酸盐缓冲溶液中,峰电流与多巴胺浓度在8.0×10-7～5.0×10-4mol L范围内呈良好的线性关系,检出限为5.0×10-8mol L。已用于药剂中多巴胺的测定。     

聚L-谷氨酸修饰电极的制备及对多巴胺的测定

用循环伏安法制备了聚L-谷氨酸修饰玻碳电极,研究了多巴胺在聚L-谷氨酸修饰电极上的电化学行为,建立了测定多巴胺的新方法。在pH 7.5的磷酸盐缓冲溶液中,用循环伏安法测定多巴胺的线性范围为1.0×10-4~4.0×10-8mol.L-1,检出限为5.0×10-9mol.L-1。该法用于药剂中多巴胺的测定,结果满意。     

聚L-白氨酸修饰电极伏安法测定痕量多巴胺的研究

用循环伏安法制备了聚L-白氨酸修饰玻碳电极,研究了多巴胺在聚L-白氨酸修饰玻碳电极上的电化学行为,建立了循环伏安法测定痕量多巴胺的新方法。实验结果表明,在pH 6.0的磷酸盐缓冲溶液中,多巴胺在聚L-白氨酸修饰玻碳电极上产生一对灵敏的氧化还原峰,峰电位分别为Epa=0.281V,Epc=0.170 V(相对Ag/AgCl电极)。峰电流与多巴胺的浓度在5.0×10-8~5.0×10-4mol/L的范围内有线性关系,检出限为5.0×10-9mol/L。对1.0×10-5mol/L多巴胺溶液平行测定9次,其相对标准偏差为4.0%。已用于针剂中多巴胺的测定。     

多巴胺在聚2,4,6-三甲基吡啶修饰电极上的电化学行为

用循环伏安法制备了聚 2 ,4 ,6 三甲基吡啶修饰玻碳电极 ,研究了神经递质多巴胺在该聚合物薄膜修饰电极上的电化学行为。实验结果表明 :在pH 7.4磷酸盐缓冲溶液中 ,多巴胺在该修饰电极上的线性范围为4 .0× 10 -6～ 1.0× 10 -5mol/L。该修饰电极对抗坏血酸无响应 ,从而可有效消除其对多巴胺测定的干扰     

聚对硝基苯偶氮间苯二酚修饰电极伏安法测定多巴胺

采用循环伏安法研究了多巴胺(DA)在聚对硝基苯偶氮间苯二酚(p-nitrobenzenazo resorcinol,简称NBAR)膜修饰电极上的电化学行为,用差示脉冲伏安法对多巴胺的含量进行测定.结果表明,聚NBAR膜修饰电极对DA有明显的电催化作用.在pH4.0的磷酸盐缓冲液中,氧化峰电流与DA浓度在5.0×10-6~8.0×10-4mol/L范围内呈良好的线性关系,检测限为6.0×10-7mol/L.修饰电极可有效消除针剂中其它组分对DA测定的干扰,已用于实际样品DA含量的测定,结果令人满意.     

多巴胺在聚硫堇和Nafion双层修饰玻碳电极上的电化学行为

用电化学聚合法在玻碳电极上制备聚硫堇,然后涂渍一层Nafion膜,采用循环伏安法研究其制备和电化学性质。该电极峰电流与多巴胺(DA)在2.00×10-7~1.43×10-3mol/L浓度范围内呈良好的线性关系,检出限为6.67×10-8mol/L,相关系数为0.995。该修饰电极有效排除了抗坏血酸(AA)的干扰。并且具有良好的灵敏度、重现性、稳定性,可用于实际样品中DA的测定。     

抗坏血酸在β-环糊精/二茂铁甲酸修饰电极上的电化学行为及测定

利用主客体化学反应将二茂铁甲酸包络在β-环糊精聚合物的空穴中,用新鲜蛋清作交联剂制成β-环糊精聚合物/二茂铁甲酸化学修饰玻碳电极,用电化学阻抗法和循环伏安法研究了修饰电极的电化学性能。在pH 7.0的磷酸盐缓冲溶液中,该修饰电极对抗坏血酸的电化学氧化有很好的催化活性,氧化峰电流与其浓度在6.2×10-6~5.0×10-3mol/L范围内呈良好的线性关系,线性回归方程为ip=0.4375+0.0301C(ip:μA,C:μmol/L),相关系数r=0.9982,检出限为1.0×10-6mol/L。抗坏血酸和多巴胺在修饰电极上于不同的电位(ΔE=490 mV)被氧化,可用于多巴胺存在下选择性测定抗坏血酸。     

聚L-酪氨酸修饰电极的制备及对多巴胺的测定

用循环伏安法制备了聚L 酪氨酸修饰玻碳电极,研究了多巴胺在聚L 酪氨酸修饰电极上的电化学行为,建立了循环伏安法测定痕量多巴胺的新方法。多巴胺在pH7.0的磷酸盐缓冲溶液中,在聚L 酪氨酸修饰玻碳电极上产生一对灵敏的氧化还原峰,峰电位分别为Epa=189mV,Epc=131mV。循环伏安法测定多巴胺的线性范围为1.0×10-3～1.0×10-8mol/L,检出限:1.0×10-9mol/L。方法可用于药剂中多巴胺的测定。     

聚色氨酸膜电极相敏交流伏安法测定肾上腺素

研究了聚色氨酸膜电极的制备及其肾上腺素在该修饰电极上的相敏交流伏安特性,建立了相敏交流伏安法测定肾上腺素的电化学分析法。在pH 6.0的磷酸盐缓冲溶液中,肾上腺素的相敏交流伏安氧化峰电位在298 mV,线性响应范围为1.05×10-6~3.98×10-5mol/L,检出限为8.40×10-7mol/L。用于药剂中肾上腺素的测定,相对标准偏差小于3.84%,加标回收率为99%~104%,多巴胺、抗坏血酸和尿酸不干扰。     

核黄素的微分脉冲溶出伏安分析

采用循环伏安法和微分脉冲溶出伏安法,对核黄素在裸金电极和巯基化合物分子自组装膜修饰金电极上的电化学行为进行了研究,发现在pH4.8的B-R缓冲溶液中,核黄素在裸金电极和分子自组装膜修饰金电极上均于-0.35V左右产生一对可逆的氧化还原峰。核黄素在裸金电极和谷胱甘肽、三巯基丙酸、二巯基苯丙咪唑分子自组装膜修饰金电极上,其浓度分别在3.0×10-7～2.3×10-4mol/L、1.05×10-6～2.0×10-4mol/L、2.1×10-6～2.08×10-4mol/L、1.05×10-6～2.0×10-4mol/L范围内与微分脉冲伏安峰峰电流之间有良好的线性关系,其相关系数分别为0.9932、0.9909、0.9857、0.9832,核黄素的检出限为2.1×10-7mol/L、5.2×10-7mol/L、8.6×10-7mol/L、5.2×10-7mol/L。对浓度为1.0×10-5mol/L的核黄素进行10次平行测定,所得峰电流的相对标准偏差为2.0%。将该方法用于核黄素片剂和复合维生素B片剂的测定,结果令人满意。     

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.     

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。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

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.     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

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.     

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^-。     

Thermodynamics of the formation of oxosulfides of rare-earth elements

The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。