气相色谱法测定酚醛树脂中游离苯酚

建立气相色谱外标标准曲线法测定酚醛树脂中游离苯酚的含量。采用DB–5(30 m×0.25 mm, 0.25μm)色谱柱,程序升温,气化室温度为250℃,以火焰离子化检测器(FID)检测,检测器温度为280℃,以标准曲线外标法计算游离苯酚含量。苯酚的质量浓度在0.05～10.0 mg/mL范围内与色谱峰面积呈良好的线性关系,线性相关系数(r)为1,方法检出限为0.003 7 mg/mL。样品加标回收率为98.0%～102.0%,测定结果的相对标准偏差为1.07%～1.26%(n=6)。该方法简单、快速,测定结果准确、可靠,可用于酚醛树脂中游离苯酚含量的检测。     

气相色谱法测定胰酶中的丙酮溶剂残留量

采用气相色谱测定了胰酶中残留的丙酮溶剂,并通过外标法定量分析其含量。气相色谱条件为:氢火焰离子化检测器(FID),DMF作为溶剂,DM-WAX色谱柱(30 m×0.53 mm×1μm),载气为氮气,进样口温度为200℃,检测器温度为300℃,柱温采取程序升温。气相色谱法检测丙酮的加标回收率为92.5%～98.0%,检出限(3S/D)为0.05μg/mL。     

气相色谱法测定黄芪饮片中有机氯类农药残留

采用气相色谱电子捕获检测器(ECD)测定黄芪饮片中9种有机氯类农药残留。黄芪饮片样品以丙酮、二氯甲烷提取,浓硫酸磺化,采用HP–5(30 m×0.32 mm,0.25μm)色谱柱,气化室温度为250℃,检测器温度为300℃。以标准曲线法计算农药含量,加标回收率为94.5%~104.4%,测定结果的相对标准偏差为1.7%~2.7%,检出限为0.061~0.175 ng/m L。该方法简单、快速、稳定、可靠,可用于黄芪饮片中9种有机氯类农药残留的测定。     

气相色谱法测定氯氟吡氧乙酸十二酯的含量

建立测定氯氟吡氧乙酸十二酯含量的气相色谱(外标法)检测方法。色谱柱为二甲基聚硅氧烷毛细管柱(0.53mm×30m×1μm);柱温:初始150℃,保持3min,30℃·min-1,程序升温至270℃,保持10min;气化室温度:280℃;检测器温度:280℃;载气为氮气。测定的RSD为0.60%,回收率在95.92%~103.72%之间,线性相关系数为0.9992。该本系操作方便、快速,结果有较好重现性,能达到含量测定目的。     

凝胶柱前处理-气相色谱法测定火腿中多种有机膦农药残留量

用乙腈萃取火腿试样中的残留农药,所得萃取液经凝胶渗透色谱柱净化后用气相色谱法(带火焰光度法检测器)测定了9种农药的残留量,用外标法定量。HP-1701型毛细管色谱柱(30 m×0.53 mm,1.0μm)用于气相色谱分离,采用柱温250℃和检测器温度230℃,载气为氮气,流速为10 mL.min-1,测得三唑膦农药的测定限为2.8μg.kg-1,其它8种有机膦农药的测定限均为5μg.kg-1。用标准加入法测定回收率,9种农药的回收率均在70%以上。     

气相色谱法测定聚异丁烯丁二酸酐中游离酸酐

建立气相色谱法测定聚异丁烯丁二酸酐中马来酸酐含量的方法。样品用有机溶剂萃取后进色谱柱分离。色谱柱采用HP-FFAP极性毛细管柱（30 m×0.32 mm,0.25μm）,载气为高纯氮气,分流比为1∶40,进样口温度为240℃,采用程序升温方式,初始温度为50℃,以10℃/min的速率升温至230℃,保持10 min,氢火焰离子化检测器温度为260℃。马来酸酐的质量分数在0～0.40%范围内与色谱峰面积线性良好,相关系数大于0.999。样品加标回收率为96.72%～99.35%,测定结果的相对标准偏差为1.172%～1.949%(n=6)。该方法操作简便、快捷、准确度高,可以满足实际生产需求。     

气相色谱法测定间甲酚异丙基化产物中麝香草酚

提出了气相色谱测定间甲酚异丙基化反应产物中麝香草酚含量的方法。采用DB-1毛细管色谱柱,柱温为175℃,气化室温度为210℃,氢火焰离子化检测器温度250℃。以甲苯为内标物,所测得麝香草酚标准与内标的峰面积比值与麝香草酚的质量浓度在200 g.L-1范围内呈线性。测得方法的回收率为100.6%,相对标准偏差(n=7)为1.31%。由根据测定数据计算的麝香草酚产率可见,采用-γAl2O3作为催化剂的气相催化法,间甲酚异丙基化的效率最高。     

高效液相色谱法测定卡格列净中葡萄糖酸-δ-内酯的含量

提出了高效液相色谱-电雾式检测器法(HPLC-CAD)测定卡格列净中葡萄糖酸-δ-内酯(GDL)的含量。优化的色谱条件如下:Thermo Hypersil Gold Aq色谱柱(250 mm×4.6 mm,5μm),流动相为乙腈(9+1)混合溶液,流量0.5mL·min~(-1),柱温30℃,进样量10μL;电雾式检测器(CAD)的雾化温度为50℃,载气压力427.5kPa。在上述的色谱条件下,GDL的线性范围为1.05~22.5mg·L~(-1),GDL的检出限(3S/N)为0.32ng。在3个浓度水平上进行加标回收试验,测得回收率在96.2%~103%之间。供试品加标溶液和对照品溶液在室温条件下放置12h内稳定,测定值的相对标准偏差(n=7)分别为1.8%,1.3%。     

气相色谱法测定苯直接加氢烷基化产物组成

建立了气相色谱法测定苯直接加氢烷基化反应产物的检测方法. 色谱条件:AT.FFAP 色谱柱(50 m×0.32 mm×0.50 μm), 氢火焰检测器,分流比为50∶1,进样器温度为180 ℃,检测器温度为200 ℃,柱温采用程序升温:初始温度80 ℃,恒温4 min后,以15 ℃/min的升温速率升至180 ℃,恒温8 min,进样量0.2 μL. 试验结果表明,甲基环戊烷、环己烷、环己烯、苯、环己基苯和二环己基苯可有效分离,检出限分别为1.4×10-7、1.4×10-7、1.4×10-7、1.6×10-7、2.7×10-7和5.3×10-6 mg/L,检出限和定量限低,各物质线性关系良好,相关系数r均在0.996以上,各物质的相对标准偏差在0.62%~1.87%之间. 方法操作简单,准确度高,可用于苯直接加氢烷基化反应产物的测定.     

气相色谱法测定木香中去氢木香内酯的含量

建立气相色谱法测定木香中去氢木香内酯的含量。选择HP–5毛细管色谱柱(30m×320μm,0.25μm),用FID检测器检测,进样口温度为280℃,柱温箱初始温度为150℃,保持3 min,以12℃/min升温至280℃,载气为氮气,流量为3.0 mL/min。去氢木香内酯的质量浓度在1.996～199.6μg/mL范围内与色谱峰面积呈良好的线性,线性相关系数r=0.999 5,加标回收率为98.26%～100.87%,6次平行测定结果的相对标准偏差为0.69%(n=6)。该方法简单,重现性好,可用于木香中去氢木香内酯含量的测定。     

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。     

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。     

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.     

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.     

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。     

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.     

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.     

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。