柱上巯基化衍生-SPE/GC/MS测定强干扰有机液体样品中的路易氏剂-1和路易氏剂-2

创建了柱上分步巯基化衍生SPE测定强干扰有机相中路易氏剂-1(L-1)和路易氏剂-2(L-2)的方法.利用优化的条件,测定L-1和L-2在5.0～30 μg/mL的浓度范围内呈良好的线性关系,同时对浓度各为5.0、10 μg/mL的L-1和L-2加标回收率分别为102.9%、78.0%和103.9%、78.0%,且相对标准偏差均小于10%.该方法不仅克服了目标化合物醇解和溶剂变换过程中造成的损失,而且可实现烷基膦酸酯化合物的检测,有效避免了真实样品中目标化合物的丢失,具有实用价值.     

热解吸-气相色谱-质谱联用仪检测废气中路易氏剂

建立了热解吸-气相色谱-质谱(TD-GC-MS)测定日本遗弃化学武器销毁废气中路易氏剂(L)的方法,优化了TD-GC-MS方法检测废气中L的衍生化反应条件,考察了废气中碳氢化合物和多环芳烃(PAHs)对该方法的影响,测试了该方法检测不同浓度路易氏剂的精密度和不同条件下的定量检出限。结果表明,该方法对洁净空气中和实际工况条件下路易氏剂的定量检出限分别为3.1×10~(-7)mg/m~3和1.1×10~(-5)mg/m~3(采样体积30 L)。     

气相色谱测定工作场所空气中二氟二氯甲烷

按照《工作场所有害物质监测方法》中的要求,提出了热解吸-气相色谱法测定工作场所空气中二氟二氯甲烷的方法,空气中的二氟二氯甲烷用活性碳吸附采样,随后在热解吸仪中使活性碳中的被测物质热解吸,并引入气相色谱中.以氢焰离子化检出器进行检测,二氟二氯甲烷浓度在0～2 000 mg·L-1之间呈线性,相关系数为0.998 7,方法的检出限为8.5×10-2 mg·L-1.在3种不同浓度水平(500,1 000,2 000 mg·L-1)进行方法的精密度试验,所得RSD值在2.0%～4.6%之间.根据试验数据算得每100 mg活性碳对二氟二氯甲烷的穿透容量为20 mg,对不同浓度的二氟二氯甲烷的热解吸效率均在90%以上,所提出的方法适用于工作场所空气中二氟二氯甲烷的现场监测.     

染毒全血与尿样中痕量路易氏剂的气相色谱-原子发射光谱联用法检测

将气相色谱-原子发射光谱联用法应用于染毒人全血及尿样中路易氏剂及其水解产物的测定.该文基于路易氏剂的结构和毒理特性,采用其特效解毒药2,3-二巯基丙硫醇(BAL)作为衍生化试剂,结合液-液萃取对样品进行预处理和富集,以气相色谱-原子发射光谱联用法定性定量.所建立的分析方法用于染毒人全血及尿样的检测,其检出限分别为50、20 μg/L(S/N＝3),相对标准偏差小于5.4%.该方法为确证路易氏剂染毒提供了一种直接的溯源性检测方法,尤其适用于BAL治疗后生物医学样品中路易氏剂的检测.     

热解吸-气相色谱法检测空气中邻氯化苯亚甲基丙二腈

运用热解吸-气相色谱法对空气中邻氯化苯亚甲基丙二腈的检测方法进行了研究.采用中心复合设计法优化了邻氯化苯亚甲基丙二腈的热解吸参数,通过方差分析找出影响响应的显著因素,最小二乘法得到二次多项式回归方程预测模型,并利用响应曲面法推导出热解吸参数的最优条件,试验证明预测的准确性较好.同时模拟了空气中样品的测定,测得值为115,646 ng,回收率分别为77%和86%.     

纳氏试剂分光光度法测定土壤中全氮含量

提出了纳氏试剂分光光度法测定土壤中全氮含量。以硫酸铜为加速剂,用硫酸对土壤样品进行消解。消解完毕的溶液用400g·L-1氢氧化钠溶液调节其酸度至pH 10左右,溶液与沉淀一起移入容量瓶中,定容至200mL。移取上清液10mL于50mL比色管中,加入酒石酸钾钠溶液作掩蔽剂,加入纳氏试剂显色后,加水定容,于波长420nm处测量其吸光度并计算土壤样品中全氮含量。氮的质量浓度在2mg·L-1以内与吸光度呈线性关系。方法用于土壤样品分析,测定值与滴定法测定值相符,测定值的相对标准偏差(n=10)为0.24%;回收率在92.3%~112%之间。     

冷蒸气发生-原子吸收光谱法测定大米中痕量镉

采用冷蒸气发生-原子吸收光谱法测定大米中痕量镉。大米样品经硝酸-高氯酸(5+1)混合酸消解后,在盐酸(5+95)溶液中加入溶于8 g·L-1氢氧化钠的25 g·L-1硼氢化钠溶液使与溶液中镉离子反应生成镉气态原子。分析中采用载气流量为0.8 L·min-1。试样溶液中加入硝酸镍和硫脲混合溶液作为增敏剂。于仪器中引入试样溶液,按选定的工作条件进行测定。镉的质量浓度在0.02~20.0μg·L-1范围内与其峰面积呈线性关系,方法的检出限(3σ)为0.005μg·L-1。应用此法对大米样品进行分析,测得镉的回收率在96.7%~103.7%之间。     

离子色谱和热解吸-气相色谱-质谱法测定炸药爆炸产物

用离子色谱和热解吸-气相色谱-质谱法测定炸药的爆炸产物.爆炸产物中的氰化物用0.1 mol·L-1氢氧化钠溶液吸收后,用离子色谱法检测,检出限(3S/N)为0.01 ug·L-1,回收率为92.6%,相关系数为0.999 8,测定结果的相对标准偏差为3.8%.爆炸产物的主成分和微量成分直接进样,用热解吸-气相色谱-质谱联用法分析,检测了联苯、1-甲基-(1H)-吡喏2-乙腈、5-氨基-3,4-二氢-(2H)-吡喏-2-乙腈、硝基苯、苯等有毒产物.     

紫外光照还原-流动注射分光光度法测定海水中硝酸盐

在pH 8.2的二乙三胺五乙酸-三羟甲基氨基甲烷(DTPA-Tris)缓冲介质中,通过紫外光照射使NO3-还原为NO2-后,与显色剂反应生成吸收峰位于540 nm波长处的化合物,据此提出了在线紫外光照还原流动注射分光光度法测定海水中硝酸盐。经试验,选择30 g·L-1氯化钠溶液作为载流,所选定的反应圈及样品环的长度依次为180 mm和130 mm。硝酸盐的质量浓度在0.009~3.0 mg·L-1范围内与相应的吸光度呈线性关系,其检出限(3s/k)为4.63μg·L-1。对同一天然海水样品按此法测定其NO3-含量10次,测得其平均值为0.538 mg·L-1,相对标准偏差为0.34%,并求得NO3-的还原率为80%。另在6个海水样品中各加0.50 mg·L-1NO3-标准溶液,按方法做回收试验,测得其回收率在97%以上。     

热解析-气相色谱法测定印刷品中总挥发性有机化合物释放量

建立用气袋法收集整册印刷品释放的挥发性有机化合物,热解析-气相色谱法检测总挥发性有机化合物(TVOC)的方法。将印刷品样品置入充满高纯氮气的密封PVF采样袋中,在35℃下放置12 h后,用采样器串联Tenax-TA采样管和采样袋,让袋内气体通过采样管,样品释放出的有机化合物被吸附到采样管的吸附剂上。用热解析-气相色谱法测试采样管中挥发性有机化合物的含量,其中苯、甲苯、邻二甲苯、间二甲苯、对二甲苯、乙苯、乙酸丁酯、苯乙烯和正十一烷按外标法定量,其它物质按甲苯标准曲线定量。该方法的加标回收率为74.4%~91.1%,测定结果的相对标准偏差不大于10%(n=9)。该方法的样品采集更贴近印刷品的实际生活场景,可以为评价印刷品挥发性有机物释放对人体健康的影响提供数据基础,为相关评价提供新思路。     

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。