微量铀的示波极谱测定

铀(Ⅵ)在含铜铁试剂的乙酸缓冲液中呈现尖锐的示波极谱峰,经初步探讨,此峰具有吸附波的性质,可用于微量铀的测定。试样经王水溶解并萃取分离干扰元素后,在1M乙酸 1M乙酸钠 0.001％铜铁试剂 5％EDTA 4％氨基三乙酸的混合底液中作示波极谱测定。铀浓度在8.5×10~(-8)-8.5×10~(-6)M范围内与峰高成直线关系,适合于钨、钼含量不高的矿石中微量铀的测定。     

电感耦合等离子体原子发射光谱(ICP-AES)法测定蒙药壮西六味散中15种元素

用微波消解和灰化法对蒙成药壮西六味散进行预处理,并用电感耦合等离子体原子发射光谱（ICP-AES）法同时测定了15种常量、微量及重金属元素的含量,进行了加标回收实验。结果显示,壮西六味散中Ca、P和K的含量较高,富含Mg、Na等营养元素,Pb、Cd等重金属含量均低于国家标准;灰化法和微波消解法两种预处理方法对测定结果基本一致。相对标准偏差（RSD）在1.6%-3.5%,加标回收率为95.5%-103%。方法简便准确、选择范围广、可高效快速准确测定壮西六味散中各元素含量。     

微波灰化-电感耦合等离子体发射光谱法测定婴幼儿乳粉中的钙和磷

采用微波灰化-电感耦合等离子体发射光谱法（ICP-OES）测定婴幼儿乳粉中钙、磷元素含量.采用微波灰化法对婴幼儿乳粉进行前处理,正交试验方法确定微波灰化最佳条件,灰化后产物用2 mL硝酸溶液(体积比为1∶1)溶解后,用ICP-OES对钙、磷元素进行含量检测.磷加标回收率为86%～104%,钙加标回收率为87%～96%.磷的相对标准偏差为2.5%～7.0%,钙的相对标准偏差为3.9%～10.0%,能够满足日常检测要求.采用微波灰化法对婴幼儿乳粉中钙、磷元素进行样品前处理,相比微波消解方法,具有用时短、用酸量少、消解效果好、不需要进行赶酸处理等优点.与干法灰化和湿法消解相比大大减少了样品处理时间.采用微波灰化与ICP-OES结合对婴幼儿乳粉中的重要指标元素进行检测,在婴幼儿乳粉质量控制中有很好的应用价值.     

差分脉冲溶出伏安法测定陶瓷器皿中铅和镉的溶出率

采用4%的乙酸浸泡陶瓷样品24 h,应用同位镀汞差分脉冲溶出伏安法测定了陶瓷样品中微量重金属铅、镉的溶出量。以0.1 mol/L的硝酸溶液做底液,0.1 mol/L的KCl溶液做支持电解质,2 g/L的Hg2+溶液做镀汞液,测得铅的溶出峰电位为-0.5 V(vsSCE),镉的溶出峰电位为-0.7 V(vsSCE),两者含量在5×10-4～1 mg/L和5×10-4～0.5 mg/L范围内峰电流和其含量呈良好的线性关系,检出限分别为2×10-4和4.3×10-3mg/L。     

半消解-石墨炉原子吸收光谱法测定土壤中镉

土壤样品常用的消解方法有全量消解和半消解两种方法,全量消解用氢氟酸除去硅酸盐,使用器皿要求较高,而且要赶尽氢氟酸,防止残余的氢氟酸腐蚀玻璃器皿,半消解法消解土壤样品,避免使用氢氟酸,消解比较简单,使用器皿要求较低.有关用半消解法测定土壤中重金属元素[1-3]]的报道很少.镉元素有化学致癌作用[4],检测方法主要有分光光度法、原子吸收光谱法、荧光光谱法、电感耦合等离子体质谱法、极谱法、中子活化分析法[5]等方法.石墨炉原子吸收光谱法由于灵敏度高,样品用量少,分析速度快等特点而得到广泛应用.本法采用盐酸一硝酸一高氯酸消解土壤样品,石墨炉原子吸收光谱法测定镉的含量,使用传统的湿法消解,操作简单方便,消解完全,结果准确.     

示差脉冲阳极溶出伏安法测定莲子芯中微量铅

采用自制丝网印刷微电极,结合阳极溶出法对微波消解后的莲子芯中的微量铅进行了测定.考察了微波消解条件、缓冲溶液pH值、富集电位、富集时间、脉冲强度、脉冲周期等对检测的影响.试验结果表明:在pH 3.6的乙酸-乙酸钠缓冲溶液中,-1.1 V富集10 s后,电流与铅的质量浓度在1～1 000μg·L-1范围内呈线性关系,相关系数为0.996.测定结果的相对标准偏差(n=5)小于5%,加标回收率为101.9%.     

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-电感耦合等离子体质谱法测定土壤中10种重金属元素

利用硝酸、盐酸、氢氟酸混合液和微波消解仪密闭消解样品，建立了一种微波消解-电感耦合等离子体质谱（ICP-MS）法同时测定土壤中铜、铅、锌、锰、钒、铬、镉、镍、锡、铊10种重金属的分析方法。取0.100 0 g土壤样品于消解罐中，采用4 mL硝酸+1 mL盐酸+1 mL氢氟酸消解体系按照设定程序进行微波消解，冷却，定容后利用电感耦合等离子体质谱法进行。结果表明，以铑元素作为内标，10种重金属元素在一定的质量浓度范围内与其信号强度呈线性关系，线性相关系数均不小于0.999 8，检出限为0.010～0.92 mg/kg。对3种标准物质进行测定，测定值的相对标准偏差为2.89%～7.72%(n=10)，相对偏差为-5.95%～4.11%。该方法分析流程简单，工作效率高，检出限低，适合大批量土壤样品的多元素同时分析。     

石墨炉原子吸收光谱法测定施用稀土微肥后魔芋中的镉、铅和铬

为了解施用稀土微肥是否对魔芋中的重金属有缓解富集作用,通过对HNO3-HClO4及HNO3-H2O2湿法消解和干法灰化3种样品前处理方式的选择以及石墨炉原子吸收升温方式的优化,建立了灵敏度高、准确性好的GFAAS法,测定魔芋中镉、铅和铬的含量.运用本法对施用稀土微肥后魔芋中上述元素的含量进行测定,结果表明,稀土微肥能够减缓镉、铅和铬重金属元素在魔芋中的积累.     

电感耦合等离子体发射光谱(ICP-OES)法测定快递包装中5种重金属元素

快递包装用硝酸-过氧化氢在微波辅助消解后,采用电感耦合等离子体发射光谱(ICP-OES)法同时测定其中的铅、镉、砷、锌、铜5种重金属元素含量.实验表明,5种元素的仪器检出限在0.2～1.0 mg/kg,6次重复性相对标准偏差(RSD)在0.20％ ～1.4％,加标回收率在82.0％ ～94.7％.10批次快递包装中有铅...     

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。