微波消解-氢化物发生原子荧光法

采用微波消解样品，氢化物发生原子荧光法，测定了牡蛎壳中微量砷的含量；通过试验，优化了微波消解的条件和仪器的最佳工作参数；结果表明该法具有快速、简便、准确等特点，砷的检出限为0.05μg/L，线性范围0-32μg/L；样品分析结果的相对标准偏差为0.44%(n=6)，加标回收率98％。     

氢化物发生原子荧光光谱法测定污泥中的砷

用氢化物发生原子荧光光谱法测定污泥中的砷.分别用微波消解、湿法消解两种方法处理污泥样品，微波消解效果优于湿法消解，在最佳实验条件下，砷的检出限为0.04μg/L，回收率为94．2％～104.8％，测定结果的相对标准偏差为2．22％～4．23％。     

微波消解-原子荧光光谱法测定化妆品中的砷

建立了微波消解-原子荧光光谱法测定化妆品中微量砷的方法.砷浓度在0～50.00μg/L范围内与荧光强度呈线性关系,线性方程为,If=56.5486c,相关系数r=0.9993,砷的检出限为0.084μg/L.砷测定结果的相对标准偏差为1.49%(n=6),加标回收率为90.7%～107.5%.用该法对环境标准样品进行测定,结果与标准值相吻合.     

虾粉中总砷测定方法的探讨

用氢化物原子荧光光度法测定虾粉中总砷含量时,对干法灰化、湿法消解、微波消解3种样品处理方法对虾粉中砷元素测定结果的影响进行了比较。通过试验确定了最佳消解条件。砷元素浓度在0~10μg/L的范围内与荧光强度呈线性关系,线性相关系数r=0.999 6,检出限为0.2μg/L。比对结果表明,干法灰化适合于测定虾粉中总砷的含量,湿法消解测定总砷的含量偏低,微波消解不适合测定虾粉中总砷的含量。采用干法灰化-氢化物原子荧光光度法测定虾粉中总砷含量,加标回收率为76.2%~106.0%。     

微波消解原子荧光光谱法测定生物样品中砷汞

采用微波消解样品预处理技术和原子荧光光谱法,测定了生物样品中砷和汞的含量。确定了微波消解样品的条件,优化了仪器的最佳工作参数。砷和汞的含量分别在0~20μg.L-1和0~16μg.L-1范围内线性良好。砷和汞的回收率分别为100.5%和98.6%。砷和汞的检出限分别为0.21和0.06μg.L-1。试验表明,该法快速简便、准确灵敏,应用于生物样品中砷、汞的测定,结果满意。     

微波消解-氢化物发生原子荧光法测定塑料原料及其制品中的砷、汞

采用微波消解进行样品前处理，以硫脲为预还原剂，用氢化物发生原子荧光法测定塑料原料及其制品中的砷、汞。测定砷和汞的线性范围均为0～8μg／L，砷、汞的检出限分别为0．005、0．076μg／L，测定结果的相对标准偏差分别为4.96％～7．38％、2．94％～7．20％(n=6)，回收率分别为92．0％～103．2％、92．0％～98.0％。     

微波消解-原子荧光光谱法同时测定鱼体中砷和汞

为建立微波消解-原子荧光光谱法同时测定鱼体中砷和汞的测定方法,采用微波消解方法,双道原子荧光光谱法同时测定了鱼体中砷和汞的含量。结果表明,砷与汞的线性范围分别为0.2~2.0μg/L,0.0~50.0μg/L;相关系数分别为r=0.999 8和r=0.999 5;砷回收率为96.5%~101.5%之间,相对标准偏差(n=11)为1.22%,检出限为0.004 2μg/L;汞回收率为98.6%~103.0%,相对标准偏差(n=11)为0.67%,检出限为0.009 6μg/L。用该法测定鱼类中砷和汞,方法灵敏度高、操作简便快速、结果准确可靠。     

碱性模式氢化物发生原子荧光光谱法测定铁矿石中砷

建立了碱性模式氢化物发生原子荧光光谱法测定铁矿石中砷的最佳仪器和实验条件。采用微波消解分解样品,在硫脲和L-半胱氨酸存在下将As（Ⅴ）还原为As（Ⅲ）,以1mol／L KOH作为介质,以0．75mol／L H3PO4作为载流,原子荧光光谱法测定样品中的砷。方法检出限为0．35μg／L,RSD在2．0％。9．4％之间,加标回收率95％～103％。对标准样品进行分析验证,结果与标准值相符。应用于铁矿样品的测定,结果满意。     

微波王水消解不赶酸原子荧光光谱法测定土壤中的砷

采用微波消解土壤样品不赶酸的情况下利用原子荧光光谱法测定土壤中的砷.结果表明:微波王水消解土壤样品不赶酸情况下,砷的测定值均在国家标准物质ESS-1的推荐值范围内.砷的线性范围分别为0.0～50.0μg/L,相关系数为r=0.9995.按称取0.2 g样品,定容至50 mL,求出砷检出限为0.5 mg/kg.砷回收率为93.4%～100.9%之间,相对标准偏差(n=4)为0.39～4.56%.结果表明:微波王水消解不赶酸原子荧光光谱法测定土壤中的砷,灵敏度高,操作简便快速,结果准确可靠.     

微波消解-石墨炉原子吸收光谱法分析测定食用菌中总砷

摘 要：采用微波消解-石墨炉原子吸收光谱法分析测定食用菌中总砷。取可食部分的食用菌粉碎均匀,采用微波消解对样品进行消解,将消解液于140℃赶酸至0.5mL ,用超纯水转移定容至25mL。以0.1%的硝酸钯为基体改进剂,塞曼扣背景,用石墨炉原子吸收光谱法测定总砷。方法检出限为0.4μg/L,线性范围为0~30 μg/L,线性相关系数(r)大于0.998,采用精密度考察方法重现性,不同浓度水平的RSD%均小于6.6%;三个浓度水平的加标回收率为80.6% ~ 103.9%,有证标准物质测定结果符合要求。实验结果表明,方法操作简便、灵敏、准确,适合食用菌中总砷的测定。对砷形态复杂的野生食用菌,微波消解后可直接采用石墨炉原子吸收光谱法测定总砷。     

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.     

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。     

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^-。     

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.     

解决能源问题的新途径——光解水制氢的研究

面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。