火焰原子吸收光谱法测定煤及煤基活性炭中微量金属元素

提出了火焰原子吸收光谱法测定煤及煤基活性炭样品中微量元素铜、锌、锰、铁、钙、镁、锡的方法,煤及煤基活性炭样品研磨成粉末状后,按GB 212-1991标准方法规定的灰化条件将样品灰化,灰化样品用高氯酸、氢氟酸溶解后,再经盐酸(1+1)溶液溶解,过滤,按仪器工作条件测定.按标准加入法做回收试验,测得回收率在96.7%～100.9%之间.对7元素分别做精套度试验,求得相对标准偏差(n=6)均小于1%.     

活性炭吸附-石墨炉原子吸收光谱法测定土壤样品中铊

土壤试样用经盐酸-硝酸-高氯酸-氢氟酸混合酸溶解后,以活性炭吸附分离样品溶液中痕量铊,用热的草酸铵溶液进行淋洗分离,采用石墨炉原子吸收光谱法测定土壤中痕量铊。以0.06μg·L~(-1)氯化钯溶液作为基体改进剂,选择灰化温度、原子化温度分别为700℃和1 700℃。铊质量浓度在0.006～200μg·L~(-1)范围内与吸光度呈线性关系,方法检出限(3s/k)为0.2 pg。方法用于分析土壤样品,回收率在93.3%～106.2%之间,相对标准偏差(n=6)在0.6%～1.8%之间。     

微波灰化-电感耦合等离子体原子发射光谱法测定原油中的金属元素

采用微波灰化技术消化原油样品,并使用电感耦合等离子体原子发射光谱法(ICP-AES)测定其中Na、Mg、Ca、Fe、V、Ni和Cu的含量。探讨了原油样品中金属元素测定的称样量和微波灰化程序,并优化了仪器工作参数和实验条件。样品经微波灰化处理后,用盐酸溶解残渣,方法对Na、Mg、Ca、Fe、V、Ni和Cu元素的检出限分别为0.07、0.01、0.01、0.01、0.02、0.04和0.03mg/kg,回收率在84.5%～96.6%之间,相对标准偏差在2.1%～6.9%范围。方法简便、可靠,可用于原油中Na、Mg、Ca、Fe、V、Ni和Cu 7种金属元素的检测。     

石墨炉原子吸收光谱法测定工作场所空气中铬及其化合物

于工作场所采用微孔滤膜采样夹以5L.min-1流量采集空气样品15min,用石墨炉原子吸收光谱法测定其中铬的含量。选择灰化温度为1 300℃,原子化温度为2 400℃。铬的质量浓度在5mg.L-1以内与其吸光度呈线性关系,检出限(3s/k)为6.81×10-4 mg.m-3。应用此法分析了采集的空气样品,加标回收率在98.8%～100.7%之间,相对标准偏差(n=6)在2.2%～2.4%之间。     

直接稀释进样-电感耦合等离子体原子发射光谱法同时测定原油中20种元素

原油样品(2.0g)用稀释剂航空煤油稀释至20.0g后,直接进样供电感耦合等离子体原子发射光谱法测定其中银、铝、硼、钡、钙、镉、铬、铜、铁、镁、锰、钼、钠、镍、铅、硅、锡、钛、钒和锌等20种元素的含量。在优化的试验条件下,20种元素的检出限(3S/N)在0.1～3mg·kg-1之间。方法用于分析原油样品,所得测定值的相对标准偏差(n=6)在1.24%～6.23%之间,回收率在80%～105%之间。     

火焰原子吸收光谱法测定抗癌中草药中11种微量元素

采用在600℃灰化法处理样品,浓硝酸溶解灰化残渣,溶液定容为50 mL,用火焰原子吸收光谱法测定了20种抗癌中草药中钙、锾、锰、铜、铁、锌、镉、铅、钴、镍、铬等11种微量元素.结果表明:抗癌中草药中除含有丰富的钙、镁、铁外,还含有较高含量的锌、锰、铜等对人体有益的微量元素.以丹皮样品为基体,加入11种元素的标准溶液作回收试验,回收率在92.3%～107.5%之间,相对标准偏差(n=5)在2.1%～5.2%之间.     

悬浮液进样-火焰原子吸收光谱法测定花粉中微量元素

提出了不使用稳定剂,直接用蒸馏水制成花粉样品的悬浮液进样,火焰原子吸收光谱法测定花粉中微量元素的方法.用三氯化镧和氯化铯消除干扰,在磁力搅拌下进样,应用标准加入法在同一溶液中用火焰原子吸收光谱法测定铜、铁、锰、锌、铅、镉、钙、镁、钾、钠等10种元素含量.方法的回收率在92.5%～112.5%之间,相对标准偏差(n=6)在0.24%～1.50%之间,并以高温灰化法的测定值为参考对测定结果进行F检验和t检验,发现两者无显著性差异,说明悬浮液进样法的测定结果准确可靠.     

氢化物发生-原子吸收光谱法测定柠檬酸中微量铅

柠檬酸样品经硫酸处理及在550℃灼烧灰化,残渣溶于盐酸(5+95)溶液中。用铁氰化钾将溶液中铅(Ⅱ)氧化成铅(Ⅳ),然后再以硼氢化钾为还原剂,盐酸(1+99)溶液为载流,用氢化物发生-原子吸收光谱法测定铅含量。在优化的试验条件下,铅的质量浓度在20μg·L~(-1)以内与其吸光度呈线性关系,检出限(3σ)为2.6μg·L~(-1)。用此方法分析了3个柠檬酸样品,测定值的相对标准偏差(n=6)小于5%,加标回收率在90.5%～110.0%之间。     

微波消解样品-石墨炉原子吸收光谱法测定食品添加剂中铅和镉含量

提出了石墨炉原子吸收光谱法测定食品添加剂中铅和镉含量的方法。样品用硝酸及过氧化氢作溶剂,使用微波消解的方法处理。以磷酸二氢铵为基体改进剂,铅和镉灰化温度分别为600℃和400℃,原子化温度分别为2 100℃和1 800℃。在优化的试验条件下,测得铅和镉相对标准偏差(n=6)分别为2.8%～6.5%和2.4%～5.3%,7种食品添加剂中铅和镉的回收率在94%～102%和96%～103%之间。     

石墨炉原子吸收光谱法测定土壤中铅、镉含量

土壤样品经硝酸、氢氟酸和过氧化氢加热消解,采用石墨炉原子吸收光谱法测定其中铅和镉的含量。以磷酸铵作为基体改进剂,铅和镉的灰化温度分别为400℃,250℃,原子化温度分别为2 100℃,1 800℃。铅和镉的质量浓度分别在0.50～50.0,0.10～2.5μg.L-1范围内与其吸光度呈线性关系,检出限依次为6.5,0.4pg。应用此法分析了4个土壤标准样品,测定值与标准值相符,相对标准偏差(n=6)分别在1.5%～6.3%和2.3%～5.1%之间。铅、镉的加标回收率分别在85.4%～103.2%,91.5%～102.3%之间。     

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。