光催化降解过程中苯酚的分光光度法测定

提出了用双波长紫外分光光度法测定含对苯醌和苯酚混合液中苯酚的方法,解决了用分光光度法直接测定苯酚时对苯醌分析的干扰。选择测定波长为270和292nm。用于纳米二氧化钛光催化降解苯酚过程中苯酚的测定。标准样品的加标回收率为：99.79％～101．17％,相对标准偏差小于0．50％;样品测定的加标回收率为：99．14％～104．75％,相对标准偏差小于2．20％,苯酚的检出限为0．10mg／L。     

红外分光光度法测定粉尘中游离二氧化硅的含量

建立一种有效的红外分光光度法测定粉尘中游离二氧化硅含量,并对样品处理和曲线绘制方法进行了改进.游离二氧化硅含量在0～100.85 mg范围内与吸光度有良好的线性关系,相关系数r＝0.999 6.样品加标回收率为80.35%～92.77%,测定结果的相对标准偏差不大于5.06%(n=5).     

紫外法与红外法测定石油类的比对研究

本文将新近实施用于测定地表水中石油类的紫外分光光度法与红外分光光度法的方法特性参数以及应用于各类实际水样测定进行了比对研究。实验结果表明,两种方法的检出限、测定下限、精密度和准确度等性能指标相近,但在应用于各种不同来源和组成水体的实际样品测定时,紫外法所得结果与红外法有明显的差异,表明该方法对较复杂水体石油类样品的测定存在局限性。     

紫外分光光度法检测水中微量溴酸盐的含量

基于BrO3-与I-在酸性介质中发生氧化还原反应形成具有紫外吸收的I3-的性质,采用了紫外分光光度法测定水体中微量溴酸盐含量,方法加标回收率在98%～102%之间,相对标准偏差RSD为1.7%,线性相关系数为0.9991,检测限为4.0μg/L,能满足现有标准的检测要求。     

水杨酸钠紫外分光光度法测定烟草中的总氮

建立水杨酸钠紫外分光光度法测定烟草中总氮含量的方法。烟草样品经硫酸铜–硫酸钾–浓硫酸消化,用水杨酸钠–二氯异氰尿酸钠显色后用紫外分光光度计检测,并对波长、显色剂用量和反应时间等实验条件进行了优化。总氮的质量浓度在5~60 mg/L范围内与其吸光度呈良好的线性关系,线性相关系数为0.998 8,方法的检出限为0.14 mg/L。样品分析结果的相对标准偏差为3.22%(n=6),样品加标回收率为99.30%~101.62%。该方法具有较高的精密度和准确度,尤其适用于样品量少时对烟草中总氮的测定。     

四氯乙烯吸收-红外分光光度法测定压缩空气中的油含量

建立四氯乙烯吸收–红外分光光度法测定压缩空气中的油含量。利用四氯乙烯作为吸收液,选择3 413nm作为分析谱线,在优化的实验条件下进行测定。油的质量浓度在0～60.0 mg/L范围内与吸光度呈良好的线性关系,线性相关系数为0.999 2,方法检出限为0.018 mg/L,最低检出浓度为0.012 mg/m3(以采集300 L空气样品计),测定结果的相对标准偏差为0.89%(n=6),加标回收率为91.0%～109.8%。该方法简单快捷,准确度和精密度高,可用于压缩空气中油含量的测定。     

红外分光光度法测定地下水中的石油类物质

采用红外分光光度法测定地下水中石油类物质。用四氯化碳萃取水中的石油类物质,将萃取物用硅酸镁吸附,脱除极性物质后进行测定。方法的检出限为0.014 mg/L,测定结果的相对标准偏差为0.65%~1.18%(n=l1)。用该方法对地下水样品进行测定并进行加标准回收试验,结果表明,地下水样品的加标回收率为84.0%~93.2%。该方法灵敏度高,操作简便、快速,可以满足地下水中石油类分析的要求。     

紫外消解流动注射光度法测定海水养殖废水中总氮、总磷

采用紫外消解–流动注射分光光度法测定海水养殖废水中总氮和总磷。总氮样品浓度在0.050~5.00mg/L范围内,总磷样品浓度在0.020~5.00 mg/L范围内均与峰高有良好的线性关系(r分别为0.999 90和0.999 94)。在盐度为35,进样时间为70 s,清洗时间为90 s的条件下,总氮和总磷的检出限分别为0.050mg/L和0.020 mg/L,测定结果的相对标准偏差分别为1.15%,0.60%(n=6),加标回收率分别为98.7%~101.2%和98.6%~102.5%。该方法能满足海水养殖废水中总氮和总磷的监测要求。     

微波消解-紫外分光光度法测定水中总氮

研究了用微波消解-紫外分光光度法测定水样中的总氮，结果表明，所提出的消解方法具有操作简单、省时、消解完全的特点，精密度和准确度均令人满意．方法的线性范吲为0．0242～9．60mg／L，水样加标回收率为101％～103％，相对标准偏差为0．13％～0．44％。     

烟酸生物转化产物的双波长检测研究

建立了一种利用双波长分光光度法测定烟酸酶法转化液中烟酸和6-羟基烟酸浓度的方法,选择的波长为266.5、300 nm。对烟酸生物转化产物的混合物进行分析,烟酸测定结果的标准标准偏差不大于1.30%(n=6),6-羟基烟酸测定结果的相对标准标准偏差不大于1.54%(n=6)。烟酸和6-羟基烟酸的加标回收率为95.1%～105.1%,检出限分别为0.9 mg/L和0.26 mg/L。该法与常规的HPLC方法相比,快速、准确、适于大量样品的测定。     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

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.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

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.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

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。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.