导数示波极谱法测定大气和水中痕量硫化物

本文提出以导数示波极谱法直接测定各种水质和大气中痕量硫化物,底液为0.032mol/LEDTA—0.10mol/L NaOH—0.040mol/L抗坏血酸。在—0.70V(V_·SCE)处,获得一灵敏的导数峰电流。硫化物浓度在9.38×10~(-9)～5.16×10~(-4)mol/L之间与峰电流有线性关系。检测限为3.12×10~(-9)mol/L。用本方法分别测定大气中的H_2S和水中的硫化物,获得满意结果。     

以锑电极作参比电极测定废水中硫化物

提出了以锑电极作为参比电极与Ag2 S电极组成无液接测量电池测定废水中硫化物的新方法。并研究了电极的性能 ,测定条件及干扰物质的影响。方法的线性范围 1 .0× 1 0 - 2 mol/L～ 5 .0× 1 0 - 7mol/L[S2 - ],回收率为 99%～1 0 3%     

硫代硫酸根的溶出伏安吸附性质及应用

在 0 .0 1mol·L-1LiNO3介质中 (pH 2 .70 )S2 O32 -有一灵敏的阴极溶出峰( - 0 .42V) ,其峰电流与S2 O32 -浓度在 1× 1 0 -7mol·L-1～ 4× 1 0 -6mol·L-1范围内有线性关系。当富集 2 0 0s时 ,检测限可达 5× 1 0 -8mol·L-1。溶出峰具有吸附性质 ,在悬汞电极上的吸附符合Frumkin等温式。测得在悬汞电极上的饱和吸附量为 1 .0 3× 1 0 -9mol·cm-2 。该方法用于PbS2 O3溶度积的测定 ,结果与文献值基本一致。     

废水中硫化物的快速分光光度法测定

1　引　　言滴定法和亚甲蓝法是目前广泛使用的硫化物测定法。亚甲蓝法灵敏度高 ,选择性好 ,但反应速度慢 ,重现性较差。本文用Ｋ2 Ｃｒ2 Ｏ7代替Ｆｅ3+,实验结果表明 :在Ｈ2 ＳＯ4 溶液中 ,Ｋ2 Ｃｒ2 Ｏ7+对二乙氨基苯胺 +Ｓ2 -显色反应即刻完成 ,表观摩尔吸收系数为 5 42× 10 4 Ｌ·ｍｏｌ-1·ｃｍ-1,比原乙基蓝法灵敏度提高 40 % ,线性范围为 0～ 0 .6ｍｇ/Ｌ。采用蒸馏分离方法 ,用ＮａＯＨ作吸收液 ,提出了一种适于水样中硫化物测定的快速分光光度法。方法简便快速且检测灵敏度高 ,已用于水和废水中硫化物的测定。2　实验部分2 1　…     

纸上光度法间接测定痕量硫离子

用过量的铜标准溶液与含S2-样品溶液作用,加入适量的二氯甲烷,使生成的硫化铜微晶滞留在有机相中,用纸上光度法测定残留在水相中的痕量Cu2+,间接测得样品中S2-的含量。测定的pH范围为3～6,S2-的测定范围为3×10-6～9×10-6mol·L-1,RSD小于3%。     

蘑菇组织催化氧化-流动注射荧光法测定去甲肾上腺素和左旋多巴

研究发现富含多酚氧化酶的蘑菇组织可催化溶解氧氧化去甲肾上腺素和左旋多巴在碱性条件下生成具有强荧光的三羟基和二羟基吲哚类物质 ,建立了以蘑菇组织柱为酶反应器的去甲肾上腺素和左旋多巴的流通式荧光分析法 .该法对去甲肾上腺素和左旋多巴响应的线性范围分别为 6× 10 -8～ 1× 10 -5g·mL-1和 3× 10 -8～ 1× 10 -5g·mL-1,检测限分别为 2×10 -8g·mL-1和 1× 10 -8g·mL-1( 3S/k) .该组织反应器可连续使用 14d ,对 1× 10 -7g·mL-1去甲肾上腺素和 1× 10 -7g·mL-1左旋多巴测定的相对标准偏差 (R .S .D .)均小于 3 % (n =11) .详细研究了常见离子和抗氧化剂对本体系的干扰情况 .将该体系用于药物制剂中去甲肾上腺素和左旋多巴含量的测定 ,结果与药典标准方法测得值一致 .实验结果证明了方法的可行性和可靠性     

基于甲醇自由基还原波的甲醇极谱测定

利用过硫酸根在电极上还原产生的硫酸根自由基SO4· - 将甲醇氧化成甲醇自由基HC·HOH ,该自由基还原产生极谱还原波 ,拟定了极谱测定甲醇的新方法。在 0 .0 33mol/LKH2 PO4+Na2 HPO4(pH 6.1± 0 .1 ) + 1 .6× 1 0 - 2 mol/LK2 S2 O8介质中 ,甲醇自由基还原波峰电流与甲醇浓度在 3.1 5× 1 0 - 4 mol/L～ 9 46× 1 0 - 3mol/L范围呈线性关系。用该方法测定了甲醇生产车间空气中的甲醇含量     

硫化物微生物传感器的研制与应用

研制了硫化物微生物传感器并用于测定硫化物。该传感器对 S2 -的测定线性范围为 0 .0 3～ 3.0 0 mg/L,测定一个样品需 2～ 3min;实验选出了最佳测试条件和用于实际样品分析     

导数-三波长光度法同时测定肉制品中亚硝酸盐和硝酸盐的研究

本文提出了导数三波长光度法同时测定NO_2~-和NO_3~-显色化合物的新方法,并利用自编程序完成测定,操作简单快速。该法直接测定NO_2~-和NO_3~-与间苯二酚在浓H_2SO_4介质中生成的有色产物,它们均在0～14μg/10ml范围内服从比耳定律,其表观摩尔吸收系数△εNO_3~-为8.28×10~2L·mol~(-1)·cm~(-1)和△εNO_2~-为3.85×10~3L·mol~(-1)·cm~(-1)。应用该法对市售熟牛肉和午餐肉进行了分析,获得满意结果。     

2,6-二溴-4-氯偶氮胂与铅、铋显色反应

1　引　　言含卤素的不对称变色酸双偶氮类试剂是稀土元素的优良显色剂 ,这类试剂用于铅、铋的测定也有一些报道。有文献用 2 ,6 二溴 4 氯偶氮胂在 1 .2ｍｏｌ Ｌ高氯酸中测定了铜合金及粗铜中微量铋 (ε为 9.0× 1 0 4Ｌ·ｍｏｌ- 1 ·ｃｍ- 1 )。实验发现 ,该试剂在 3 0ｍｏｌ ＬＨＣｌＯ4介质中与铋显色反应有更高的灵敏度 (ε为 1 .0 5× 1 0 5Ｌ·ｍｏｌ- 1 ·ｃｍ- 1 )。在该条件下 ,Ｐｂ2 +不干扰Ｂｉ3 +的测定 ;在 0 .1ｍｏｌ ＬＨＣｌＯ4中 ,两者均与试剂显色 ,其摩尔吸光系数分别为 4 .4 6× 1 0 4和 1 .0 3×1 0 5Ｌ·ｍｏｌ…     

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。