纳米金修饰玻碳电极测定邻苯二酚

采用恒电位沉积方法将HAuCl4直接还原成纳米金并修饰于玻碳电极表面,制备了对邻苯二酚具有电催化氧化作用的纳米金修饰电极。邻苯二酚在该修饰电极上发生一可逆的氧化还原反应。在磷酸盐缓冲溶液(pH 7.5)中,当邻苯二酚的浓度为3.0×10-3mol.L-1时,与裸玻碳电极相比,其Epa负位移了170 mV,Epc正位移了50 mV,ΔE下降为60 mV,且峰电流显著增大,氧化峰电流与邻苯二酚浓度在5.0×10-6~4.2×10-3mol.L-1范围内呈线性关系,相关系数为0.997 6,检出限(3σ)为5.0×10-7mol.L-1。在浓度为5.0×10-4mol.L-1测得RSD(n=10)为2.9%,回收率在98.0%~101.0%之间。     

聚对氨基苯磺酸修饰电极差分脉冲伏安法测定多巴胺

采用电化学方法将对氨基苯磺酸聚合在玻碳电极表面制得聚对氨基苯磺酸修饰电极,并用循环伏安法和差分脉冲伏安法研究了多巴胺在该修饰电极上的电化学行为。结果表明:在pH 7.0的磷酸盐缓冲溶液中,多巴胺在0.148 V处出现一良好的氧化峰。多巴胺浓度在4.0×10-7~1.0×10-5mol.L-1范围内与其峰电流呈线性关系,检出限(3S/N)为1.0×10-7mol.L-1。将该法用于针剂中多巴胺的测定,回收率在91.0%~112.0%之间,相对标准偏差(n=5)在2.4%~3.2%之间。     

多巴胺在镍(Ⅱ)与水杨醛谷氨酸配合物修饰的碳黑微电极上的电化学行为

制备了水杨醛谷氨酸合镍修饰碳黑微电极,在JP-303极谱分析仪上研究了多巴胺(DA)在该修饰电极上的电化学行为,试验结果表明,在pH 7.0的磷酸盐缓冲介质中,多巴胺在该修饰电极上其峰电流增强达3倍之多.产生一灵敏的氧化峰,在0.14 V处峰电流与DA浓度在2.0×10-7～1.0×10-3mol L-1范围内呈线性关系,检出限(3σ)为1.0×10-7mol·.L-1,应用于盐酸多巴胺注射剂中多巴胺的测定,测定结果的RSD(n=7)值小于3.5%,回收率为96%～103%.     

在亚硝酸盐存在下钴(Ⅱ)-中性红络合物的极谱催化波的性质

在0.2 mol.L-1的氨水-NH4Cl(pH 9.5)缓冲溶液中,1.0 mol.L-1NaNO2存在下,钴(Ⅱ)-中性红(NR)络合物于-1.19 V(vs.SCE)处产生灵敏的极谱波,二阶导数波峰电流与钴浓度在2.0×10-8~5.0×10-6mol.L-1范围内呈线性关系,检出限为1.0×10-8mol.L-1。研究了钴(Ⅱ)-中性红(NR)络合物的电极反应机理,证明了该波为不可逆极谱催化波,测得电活性络合物组成为钴(Ⅱ)∶(NR)=1∶1。电活性络合物的中心离子钴(Ⅱ)还原,电子转移数n=2。该方法用于维生素B12注射液和天然水中痕量钴的测定,测得分析结果的RSD(n=6)值均小于0.7%,回收率在98%至101%之间。     

邻苯二酚在多壁碳纳米管修饰玻碳电极上的电化学行为及其测定

叙述了多壁碳纳米管修饰玻碳电极的制备方法,多壁碳纳米管用前需经硫酸-硝酸(3+1)混合酸预处理以增强其反应活性.与裸玻碳电极相比,多壁碳纳米管修饰电极具有更高的氧化还原峰电流和更低的氧化电位.试验优化了支持电解质、pH值、扫描速率等测定条件,此法测定邻苯二酚的线性范围为4.0×10-7～8.0×10-5mol·L-1,检出限(3S/N)为6.0×10-8mol·L-1.应用于模拟水样中邻苯二酚的测定.在4个浓度水平上用标准加入法作了回收试验,测得其回收率在99.2%～103.0%之间,相对标准偏差(n=8)均小于3.5%.     

聚氨基乙酸修饰碳黑微电极同时测定多巴胺和抗坏血酸

用电化学方法将氨基乙酸聚合在碳黑微电极表面制得聚氨基乙酸修饰碳黑微电极,并用循环伏安法在pH 7.0的磷酸盐缓冲介质中,研究了该修饰电极的电化学行为.结果表明:在此缓冲介质中,多巴胺和抗坏血酸经在-200 mV(vs.SCE)富集30 s后,在此修饰电极上发生催化氧化反应,并分别在320 mV及42 mV处呈现各自的峰电位(Epa),在多巴胺和抗坏血酸的I″p值及其浓度之间分别在2.0×10-8～1.0×10-4mol·L-1,4.0×10-7～1.0×10-3mol·L-1范围呈线性关系,检出限(3σ)分别为6.0×10-9mol·L-1及1.0×10-7mol·L-1.此修饰电极有良好的重复性和稳定性,只需将用过的电极在400 mV置于同一缓冲溶液中清洗0.5～2.0 min,即可方便地再生恢复原有性能.应用此方法分析了含有多巴胺及抗坏血酸的混合溶液,测定结果的相对标准偏差(n=7)在1.6 9,6～2.6%之间,回收率在96%～104%之间.     

6-巯基嘌呤在多壁碳纳米管修饰玻碳电极上的电化学行为及其分析应用

将固体多壁碳纳米管置于10g·L-1叫六偏磷酸钠溶液中,通过超声搅拌制成均匀分散的悬浮液.取此悬浮液10μL,滴加于经抛光的玻碳电极的表面,在红外灯下烘干后即制成多壁碳纳米管修饰的玻碳电极(CNT/GCE).在pH 7.0的磷酸盐缓冲介质中,6-巯基嘌呤(6-MP)在0.357 V(vs.Ag/AgC1)处出现一灵敏的氧化峰,其峰电流(Ip)与6-MP浓度在5×10-7～1×10-4mol·L-1叫之间呈线性关系,检出限为5.0×10-8mol·L-1.应用此方法测定了3个模拟血清样品中6-MP含量,并测得方法的回收率在98.0%～104.7%之间.在6-MP浓度水平为1×10-5mol·L-1叫的条件下,测得方法的RSD(n=10)为4.2%.     

美洛昔康在乙炔黑与离子液体复合修饰碳糊电极上的电化学性质及电分析方法

运用电化学方法研究了美洛昔康(Meloxicam,MLX)在乙炔黑(Acetylene black,AB)与离子液体(1-苄基-3-甲基咪唑六氟磷酸盐,[Bn MIM]PF6)复合修饰碳糊电极(AB-[Bn MIM]PF6/CPE)上的电化学行为。实验结果表明,AB-[Bn MIM]PF6/CPE对MLX电化学氧化具有良好的促进作用。测定了MLX在此电极上的电极反应动力学参数,用SWV法测得MLX氧化峰电流与其浓度在6.0×10-7~1.0×10-5mol·L-1及1.0×10-5~1.0×10-4mol·L-1范围内呈良好线性关系,线性拟合方程分别为Ip(μA)=7.607+1 608 C(mmol·L-1),r=0.993 4和Ip(μA)=20.68+267.6 C(mmol·L-1),r=0.997 9,检出限(LOD,S/N=3)为2.2×10-8mol·L-1。同时运用该方法对市售片剂中MLX含量进行了电化学测定,RSD为1.2%~3.0%,加标回收率为96.2%~100.1%。     

Silica sol/Nano-Au/PVA/L-cysteine修饰金电极电致化学发光测定甲氧氯普胺的研究

在甲氧氯普胺对联吡啶钌具有较好电化学发光增敏效果的基础上,制备出Silica sol/Nano-Au/PVA/L-cysteine修饰金电极,并通过电致化学发光法,考察了联吡啶钌及联吡啶钌-甲氧氯普胺体系在此电极上的电化学及电化学发光行为。该修饰电极对联吡啶钌-甲氧氯普胺体系有良好的电致化学发光响应特性;在最优条件下,在1.0×10-7~1.0×10-4mol/L范围内甲氧氯普胺浓度与其对应的电化学发光强度值线性关系良好,检出限(S/N=3)为1.40×10-9mol/L;通过平行测定1.0×10-5mol/L甲氧氯普胺溶液8次,发光强度值相对偏差(RSD)为1.8%,样品回收率在98.3%~104.4%之间,RSD为2.3%(n=5)。     

石墨烯修饰玻碳电极用于循环伏安法测定盐酸表阿霉素

将石墨烯修饰在玻碳电极表面用于循环伏安法测定盐酸表阿霉素。在pH 4.0的B-R缓冲溶液中,在修饰电极上,盐酸表阿霉素在-0.382V处可见明显的氧化峰,且氧化峰电流比在裸玻碳电极上提高两倍以上。盐酸表阿霉素的氧化峰电流与其浓度在1.0×10-7~1.0×10-6 mol·L-1范围内呈线性关系,检出限(3S/N)为2.0×10-9 mol·L-1。方法用于盐酸表阿霉素注射液的测定,加标回收率在95.9%~97.7%之间,测定值的相对标准偏差(n=6)小于2%。     

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.     

探究“铁的锈蚀条件”实验创新设计

设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。