毛细管电泳非接触电导检测分离测定水杨酸及其羟基化产物

利用自组装的毛细管电泳非接触电导检测装置建立了水杨酸（SA,羟基自由基捕获剂）及其羟基化产物2,3-二羟基苯甲酸（2,3-DHBA）和2,5-二羟基苯甲酸（2,5-DHBA）的分离测定方法。在最佳条件下10min内即可完成分离,其线性范围为0．03～15．0mg·L^-1L^-1,检出限（S／N=3）为0．01mg·L^-1,对0．7mg·L^-1混合溶液进行测定,SA、2,3-DHBA和2,5-DHBA峰面积的相对标准偏差（n=8）依次为2.9％,3．2％,3．6％。     

柱后衍生高效液相色谱法测定罗汉果甜甙中黄曲霉毒素B1

用柱后衍生高效液相色谱法测定了罗汉果甜甙中黄曲霉毒素B1（AFX B1）。用MYCOTOX^TM C18作为反相色谱柱,流动相为由甲醇、乙腈及水以22＋22＋56之比例混合的混合液。柱后衍生试剂为100mg·L^-1碘的水溶液,以荧光检测器在发射波长为365nm及激发波长为430nm条件下进行测定。在AFX B1的峰面积与质量浓度（mg·L^-1）之间呈线性关系,其回归方程为y=14．222x＋0．6253（r=0．998）,在三个浓度水平（5．1,40．8及102μg·kg^-1）上进行回收率及精密度试验,所得回收率在81．4％～94．2％之间,相对标准偏差（n=10）在2．1％～4．59／5之间。     

石墨炉原子吸收光谱法测定蜂胶中铅

用浓硝酸与浓高氯酸混合液消解蜂胶试样,待试液呈无色或浅黄色时继续蒸发至冒高氯酸白烟,冷却,用0．5mol·L^-1硝酸定量稀释后,试液用于石墨炉原子吸收光谱法测定。工作曲线的线性回归方程为A=0．0016C＋0．0063（r=0．9998）,方法的检出限（S／N=3）为0．04mg·kg^-1。对蜂胶实样作了分析,铅测定值的相对标准偏差（n=6）为1．0％,回收试验结果在76．0％～105．0％之间。     

光度法测定杜仲藤中总黄酮

石油醚索氏提取除杂,甲醇索氏提取杜仲藤中各部位的总黄酮含量,所得提取液用甲醇定量稀释至100mL,分取1．0mL于10mL容量瓶中,并在碱性溶液中与铝（Ⅲ）反应后在510nm波长处测定所生成络合物的吸光度。用芦丁作标准制作校准曲线,其回归方程为C=0．09669A-0．000763,相关系数为0．9993。按此方法分析了杜仲藤样品,测得茎中总黄酮量为93．0mg·g^-1（n=6,相对标准偏差为1．62％）,叶中为96．4mg·g^-1（n=6,相对标准偏差为0．44％）。     

高效液相色谱法测定动物源食品中磺胺类药物残留量

试样中残留磺胺药物用乙腈提取并经正己烷萃取和通过碱性氧化铝层析柱进行净化。所得乙腈-水（30＋70）洗脱液用于高效液相色谱法测定。采用C18色谱柱（250mm×4．6mm）作固定相,以乙腈（A）及乙腈＋乙酸＋水（20＋1＋79）的混合液（B）按不同比例混合液作流动相进行梯度淋洗使5种磺胺药物分离,最后在270nm波长处作紫外检测,所测定的磺胺药物的质量浓度与其峰面积之间在0．05～1.00mg·L^-1范围内呈线性关系。方法的测定下限（S／N=10）为0．04mg·kg^-1,以猪肉样品为基体加入3种药物的标准溶液进行回收试验,测得回收率在73．65％～93．45％之间。     

流动注射-化学发光法测定片剂中左炔诺孕酮含量

在酸性条件下,高锰酸钾与亚硫酸钠能够产生较弱的化学发光,而左炔诺孕酮能够增强该化学发光强度。在一定浓度范围内,增加的发光强度与左炔诺孕酮的浓度呈线性关系,由此建立了一种测定左炔诺孕酮的流动注射化学发光方法。方法的检出限（S／N=3）为6．4μg·L^-1,线性范围为0．01～0．5mg·L^1-和0．5～5．0mg·L^-1,对0．1mg·L^-1左炔诺孕酮平行测定11次,其相对标准偏差为4.3％。     

高效液相色谱-质谱联用法检测烤鳗中环丙沙星

烤鳗样品中的环丙沙星分两次用经稀甲酸（1＋99）酸化的乙腈提取。收集上层清液用乙腈定容为25.0mL,分取10．0mL,在40℃氮气吹干后溶于流动相溶液2．0mL中,加入正己烷2．0mL,萃取后取10．0μL下层溶液注入于高效液相色谱-质谱分析仪中。在HPLC分析中,用XBridge^TM Shied PR18柱（250mm×3．0mm,5μm）,以体积比15比15比70混合的甲醇、乙腈和稀甲酸（2＋998）组成的混合液为流动相,并采用荧光检测（FD）（激发波长275nm,发射波长445nm）。在MS分析中,采用选择离子监测（SIM）技术在电喷雾电离正离子[ESI（＋）]模式下检测,定量离子为m／z 331．9[M＋H]^＋。检测信号的峰面积与环丙沙星浓度之间在100．0～2500．0μg·L^-1（HPLC-FD法）和20．0～500．0μg·L^-1 MS-SIM-ESI（＋）法]范围内呈线性关系,其测定限（n=10）依次为50．0,10．0μg·kg^-1。在3个浓度水平上加入环丙沙星标准溶液进行精密度和回收试验,所得相对标准偏差（n=6）均小于6．5％,回收率在83．0%～99．0%之间。     

RP-HPLC内标法测定土壤中甲磺隆和氯磺隆的残留量

采用反相高效液相色谱-内标法测定了土壤中甲磺隆和氯磺隆的含量．以苯甲醇为内标物,C18反相柱（250mm×4．6mm i．d．,5μm）为分析柱,甲醇／1％醋酸钠水溶液（Ф=50／50）为流动相,流速1．0mL/min;检测波长254nm,柱温30℃．在甲磺隆浓度3．92-39．2mg／L,氯磺隆浓度2．02～20．2mg／L范围内,各对照品与苯甲醇的色谱峰面积比呈良好的线性关系．该方法准确、快速、灵敏度高、重现性好．     

气相色谱-质谱法测定豉香型白酒中β-苯乙醇及3种二元羧酸的二乙酯

用2-乙基正丁酸为内标物,提出用气相色谱-质谱联用全扫描法测定豉香型白酒中β-苯乙醇和在特定保留时间窗内选择性离子法测定庚二酸二乙酯、辛二酸二乙酯和壬二酸二乙酯含量。此方法对β-苯乙醇的检出限（S／N=3）为5．0mg·L^-1,对其他3种二元羧酸的二乙酯的检出限均为0．01mg·L^-1,测得方法的回收率在90％～110％之间,相对标准偏差（n=10）均小于9％。     

应用液-液色谱联用技术在线富集测定环境水中西维因和抗蚜威的残留量

为高效液相色谱法测定环境水样中残留的西维因和抗蚜威的含量,应用了液-液色谱联用技术,实现了在线富集、分离和检测。分析中用YWG-C18（10mm×4．6mm,10μm）和YWG-C18（150mm×4．6mm,10μm）依次作为富集柱和分离柱,以体积比45比55混合的甲醇与水的混合溶液作为流动相,其流速为1．0mL·min^-1。选定紫外光度检测的波长为228nm,试样溶液在富集柱上的流速为5．0mL·min^-1。此外,对渗漏体积等参素也作了试验,分析信号值与两农药的质量浓度在0．04～1．0μg·L^-1范围内呈线性关系。测得方法的检出限（S／N=3）为0．008μg·L^-1（西维因）和0．014μg·L^-1（抗蚜威）,回收试验的结果在93％～119％之间。还对日内和日间精密度进行了试验,测定西维因的日内精密度为1．3％～20．0％,日间精密度为2．39／6～22．2％,测定抗蚜威的日内精密度为2．0％～10．8％,日间精密度为2．2％～5．8％。     

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。     

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。     

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。