同时裂解甲基化气相色谱法鉴别合成胶粘剂

 应用同时裂解甲基化气相色谱法 (Py Me GC)对合成胶粘剂进行了鉴别。采用热丝型裂解器、氢火焰离子化气相色谱仪、FFAP毛细管柱、程序升温方式及季铵盐甲基化试剂 ,对刑事案件中常见的丙烯酸酯类及其改性体、醋酸乙烯酯、聚乙烯醇等合成胶粘剂进行了测定 ,并对样品裂解各主要组分峰进行了GC/MS定性分析 ,同时比较了相同样本用常规裂解气相色谱法 (Py GC)测定的结果。结果表明 :Py Me GC法比Py GC法可获得更多的物质组分信息 ,是一种适用于法庭科学鉴定的方法。     

气相色谱-质谱法同时测定氧化型染发剂中的多种染料中间体

氧化型染发剂是广泛使用的永久性染发剂.因其多具致敏性或致癌性,因此我国《化妆品卫生规范》对其作了限量使用规定,并采用高效液相色谱法（HPLC）测定其中8种染料中间体,但在实际应用中由于样品基体复杂,导致分离效果不理想、定性困难等问题.《欧盟化妆品规程》采用的薄层色谱法能很好地分离和鉴别各种染料组分,但对其进行精确定量存在一定困难.我国行业标准推荐的气相色谱法只能测定其中对苯二胺一种组分,故使用价值不高.本采用气相色谱-质谱法（GC/MS）同时测定染发剂中的（1）邻苯二胺、（2）对苯二胺、（3）对氨基酚、（4）间氨基酚、（5）对苯二酚、（6）间苯二酚、（7）2,5-二氨基甲苯硫酸盐及（8）4-甲胺苯酚硫酸盐等8种氧化型染料中间体,可满足化妆品监督管理的需求.     

硅烷化衍生-气相色谱/质谱法分析糖氨反应中的2,6-脱氧果糖嗪

糖氨反应混合物之所以被广泛地用于炯草行业以改善或者增强卷烟烟气,关键在于其含有大量的吡嗪类化合物,而2-（1′,2′,3′,4′-四羟基丁基）-6-（2″,3″,4″-三羟基丁基）-吡嗪,或称2,6-脱氧果糖嗪（简称2,6-DOF,结构见图1-a）就是糖氨反应的重要产物之一。该化合物的相对分子质量较大（Mr304）,挥发性低,多羟基极性强,无法直接进行气相色谱／质谱（GC／MS）表征。本文先对2,6-DOF进行三甲基硅烷化预处理,然后用GC／MS对其进行定性和粗略的定量检测。该方法可有效地用于糖氨反应实验的跟踪。     

裂解气相色谱—数值分析技术鉴别中药材初探（Ⅰ）

裂解气相色谱法具有快速、灵敏、准确等特点,已被广泛应用于高聚物、生物大分子相微生物等的鉴别和分类,在中药材分析中的应用也有报道。我们在研究工作中发现,同属及同种不同产地中药材的裂解色谱图十分相似,用肉眼很难区别,为此,我们首次将数值分析技术引入中药材裂解色谱图的解析,并对五加科中几种名贵中药材和百合科麦冬进行了分析鉴别,结果令人满意,此法可望为中药材鉴别提供新的途径。     

气相色谱/质谱法分析羊毛脂中的甾类化合物

羊毛脂（lanolin）是由羊皮脂腺分泌出而黏附于羊毛上的多组分混合物,主要是由多种羟基脂肪酸、脂肪酸与大致等量的脂肪醇、甾醇等所形成的酯和少量游离酸、游离醇以及烷烃所组成,其中的醇类统称为羊毛醇。本文采用气相色谱-质谱（GC—MS）分析了羊毛醇中的各组分,在分析过程中发现了两种未曾报道的甾类化合物。     

用裂解气相色谱法对几株霉菌的分析

本文用带有PYR-2A管式炉裂解器和C-R2AX计算机的岛津GC-9A气相色谱仪,对3株曲霉和3株青霉进行了裂解气相色谱鉴别。通过对指纹图的分析,能够较好地区分出两属之间和各菌株之间的差异,证明了裂解气相色谱分析法用于霉菌鉴别的可能性。     

非衍生气相色谱法快速测定冰醋酸中的微量甲酸

冰醋酸是最重要的有机酸之一,甲酸是冰醋酸中的主要杂质,其含量的多少直接影响冰醋酸的质量。现行国内外标准方法是利用化学方法对冰醋酸中微量的甲酸进行测定,其操作步骤繁琐,费时费力,完成测定工作约需要几个工作日,无法满足贸易结算的快速测定的需要。目前微量甲酸一般采用衍生气相色谱法测定。对甲酸直接定量测定的方法有离子色谱法、气相色谱／质谱法（GC／MS）以及气相色谱／热导检测法（TCD）。本文利用电子捕获检测器（ECD）检测甲酸,避免了衍生化或者标记方法的繁琐及化学法费时费力的缺点,而且其灵敏度远远优于TCD和氢火焰离子化检测器（FID）,同时又克服了MS检测器不易定量的缺点,为进口冰醋酸的准确快速测定提供了技术保证。     

用裂解色谱法鉴定羧酸酯的结构

研究了用裂解气相色谱法鉴定羧酸酯结构的方法。对一些一元酸酯和二元酸酯进行了普通裂解和与碱石灰混合后的裂解,依据裂解产物可确定酯的母体酸和母体醇。直接从薄层板上取分离后的组分,不用去除吸附剂就能进行鉴定,可用于常见羧酸酯的剖析工作。     

模式识别用于裂解气相色谱研究胃癌早期诊断

模式识别是近30年来得到迅速发展的一门新兴边缘学科,已被广泛应用于人工智能、文字识别、图形识别、语音识别、谱图分析、生物医学应用、工业应用等众多领域。 裂解气相色谱是一种裂解法与色谱法联合技术,被广泛应用于医学领域。可用于多种细菌、病毒及正常细胞和病理细胞的鉴别研究,具有快速、灵敏等特点。 笔者试在裂解气相色谱分析技术中引入模式识别方法,通过对色谱曲线图的识别,对胃癌、萎缩性胃炎不典型增生及浅表性胃炎三种胃镜手术活检样本进行判别及预报,以期达到胃癌早期发现,应用于临床诊断的目的。     

不同提取方法的普洱茶气相色谱指纹图谱研究

以市售的普通茶和大益普洱茶为材料,采用气相色谱法(GC)对不同提取方法(索氏提取、微波提取、匀浆提取和超声提取)和不同溶剂(水、乙醇、丙酮、乙酸乙酯和石油醚)提取的提取液进行检测.对所得的GC指纹图谱进行整体性比较,最终建立一种简捷、整体性强、灵敏度高和分析时间短的普洱茶GC指纹图谱分析方法.     

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。     

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。     

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。