顶空气相色谱-质谱法测定烟用水基胶中7种有机化合物

建立了顶空气相色谱-质谱法快速测定烟用水基胶中7种有机化合物-乙酸乙烯酯和苯及苯系物的分析方法。采用1 mL N,N-二甲基甲酰胺分散样品密封后,在85℃温度下低速振荡平衡30 min,顶空进样,HP-INNOWAX色谱柱进行分离,质谱检测器检测,以2-己酮为内标进行定量分析。结果表明:7种有机化合物可在10 min内有效分离,且线性关系良好(r 0.999),检出限(LOD)为3.0～11μg/kg。样品加标回收率均在96.8%～103.5%范围内,相对标准偏差(RSD)不大于3.3%。该方法适合于水基胶样品中乙酸乙烯酯、苯及苯系物含量的快速分析。     

同时测定水基胶中乙酸乙烯酯和六种苯系物的方法

本发明公开了一种同时测定水基胶中乙酸乙烯酯和六种苯系物含量的方法,采用N,N-二甲基甲酰胺分散样品,双内标法进行定量,利用顶空–气相色谱–质谱联用仪,于一次进样中对烟用水基胶中的7种化合物进行同时测定;所采用的色谱条件使得苯、甲苯、乙苯、邻二甲苯、间/对二甲苯(间二甲苯和对二甲苯因色谱柱问题,没有分开,但不影响计算结果 )和乙酸乙烯酯目标物和二个内标物异丁醇、2-己酮的色谱峰都分离较好。结果显示,各组分的回归方程相关系数均达到0.999以上,苯系物的定量检出限为0.01~0.02 mg/kg,乙酸乙烯酯的定量检测限为0.10mg/kg,平均相对标准偏差为1.15%~3.75%,加标回收率在88.09%~95.44%,具有快速、准确、重复性好、回收率高等优点,具有良好的实用性。     

顶空-气相色谱法同时测定聚对苯二甲酸乙二醇酯瓶中乙醛和丙酸乙烯酯迁移量

建立了顶空-气相色谱法同时测定聚对苯二甲酸乙二醇酯(PET)瓶中乙醛和丙酸乙烯酯迁移量的方法。将食品模拟液水、4%(体积分数,下同)乙酸溶液或橄榄油灌入PET瓶中,在迁移温度为40,60℃下迁移1,10,20,30d。取10mL模拟液于22mL顶空进样瓶中,设置顶空平衡温度为80℃,顶空平衡时间为60min。气化后的样品用SH-RT-Q-BOND毛细管色谱柱在程序升温条件下分离,用氢火焰离子化检测器测定。用3种食品模拟液配制混合标准溶液系列,结果显示:乙醛和丙酸乙烯酯的质量浓度均在0.5～10.0mg·L~(-1)内与其对应的峰面积呈线性关系,检出限(3S/N)分别为0.016～0.050mg·L~(-1)和0.002～0.050mg·L~(-1);对实际样品进行3个浓度水平的加标回收试验,乙醛和丙酸乙烯酯回收率分别为96.0%～106%和94.0%～107%,测定值的相对标准偏差(n=6)分别为1.4%～5.3%和1.9%～5.2%。按此方法分析实际样品,未检出丙酸乙烯酯,乙醛在水中的迁移量大于在4%乙酸溶液和橄榄油中的,且60℃的迁移量大于40℃的,最高迁移量为4.4mg·L~(-1),低于国家标准GB 9685-2016规定的限量(6.0mg·kg~(-1))。     

气相色谱-质谱联用法测定烟用水基胶中的乙酸乙烯酯

正在卷烟生产中用于粘结烟纸、滤嘴及包装纸的水基胶是重要的卷烟辅助材料之一[1]。目前国内烟草行业使用的水基胶大多是化学合成的白乳胶。白乳胶是以乙酸乙烯酯为主要原料在引发剂作用下经聚合反应而制得的一种热塑性粘合剂[2],主要有聚乙酸乙烯均聚乳液(PVAC)、乙酸乙烯-乙烯共聚乳液(VAE)和乙酸乙烯-丙烯酸丁酯共聚乳液(VAB)等。烟用水基胶中的乙酸乙烯酯在卷烟生产过程中受生产原料、操作工艺等条件的影响会因转化不完     

顶空-气相色谱法测定葡萄中乙烯利的残留量

称取葡萄样品于预先加入氯化钠的顶空瓶中,再加入饱和氢氧化钾溶液,采用顶空-气相色谱法测定上述混合液中乙烯利的残留量。顶空温度为75℃,顶空时间为90min,采用HP-5色谱柱(30m×0.32mm,0.25μm)分离,氢火焰离子化检测器测定。乙烯利的质量浓度在0.500~50.0mg·L^-1内与其对应的峰面积呈线性关系,检出限(3S/N)为0.010 0mg·kg^-1。方法用于葡萄样品的分析,加标回收率为99.9%~104%,测定值的相对标准偏差(n=6)为1.9%~3.5%。     

顶空-气相色谱法测定乙烯-乙酸乙烯酯共聚物塑料儿童用品中甲酰胺含量

应用顶空-气相色谱法测定了儿童用品乙烯-乙酸乙烯酯共聚物塑料中甲酰胺的含量。选择顶空平衡温度和时间分别为160℃和40min,用DB-Wax色谱柱(0.53mm×30m,1μm)分离,氢火焰离子化检测器检测。以N,N-二甲基甲酰胺为内标物。甲酰胺的线性范围为1~646μg。方法用于此类共聚物塑料地垫样品的分析,加标回收率在80.9%~82.8%之间,测定值的相对标准偏差(n=6)在4.1%~4.5%之间。     

气相色谱-串联质谱法同时测定烟用水基胶中15种邻苯二甲酸酯类化合物

采用气相色谱-串联质谱法同时测定烟用水基胶中15种邻苯二甲酸酯类化合物的含量。烟用水基胶样品0.300g经2mL水分散,用10mL正己烷萃取5min。在气相色谱分离中用DB-35MS色谱柱为固定相,在质谱分析中采用多反应监测模式。15种邻苯二甲酸酯类化合物的质量浓度均在0.05~5.0 mg·L~(-1)内与其对应的峰面积呈线性关系,方法的检出限(3S/N)为0.006~0.027μg·g~(-1)。在4,20,100μg·g~(-1)等3个浓度水平进行加标回收试验,回收率为87.8%~104%,测定值的相对标准偏差(n=6)为1.3%~6.1%。     

加速溶剂萃取-气相色谱法测定乙烯-乙酸乙烯共聚物塑料制品中甲酰胺残留量

采用加速溶剂萃取-气相色谱法测定乙烯-乙酸乙烯共聚物塑料制品中甲酰胺的残留量。加速溶剂萃取条件:以无水乙醇为提取溶剂,在160℃下循环萃取3次,每次6min。用Agilent JW HP-Innowax毛细管色谱柱分离,氮磷检测器检测。甲酰胺的质量浓度在0.20~10.0mg·L-1范围内与其峰面积呈线性关系,检出限(3S/N)为0.08mg·kg-1。加标回收率在85.2%~91.7%之间,测定值的相对标准偏差(n=6)在4.5%~7.4%之间。     

基于灰色模型的乙酸乙烯酯顶空进样质量不确定度评定

鉴于静态顶空进样器进样质量的测定数据有限且分布规律未知,建立了一种基于灰色模型的不确定度评定方法。采用静态顶空-气相色谱和两次相平衡分析法,测定乙酸乙烯酯的顶空进样质量,将整个分析检测视为灰色过程,用灰色系统理论的数学模型评定乙酸乙烯酯的顶空进样质量标准差和不确定度,并与统计学方法评定结果进行比较。灰色模型的不确定度与统计学方法计算值相对偏差为3.65%。该方法可快速评定不确定度,结果可靠。     

顶空-气相色谱法测定伊班膦酸钠注射液中丙酮和乙醇残留量

采用顶空-气相色谱法测定伊班膦酸钠注射液中丙酮和乙醇的残留量。选择顶空平衡温度和时间分别为70℃和40min,用CP-WAX毛细管色谱柱(30m×0.25mm,0.25μm)分离,氢火焰离子化检测器检测。丙酮的质量浓度在0.05~120mg·L-1范围内与其峰面积呈线性关系,检出限(3S/N)为0.015mg·L-1。乙醇的质量浓度在0.25~120mg·L-1范围内与其峰面积呈线性关系,检出限(3S/N)为0.25mg·L-1。丙酮和乙醇的加标回收率分别在97.0%~112%和94.9%~112%之间。丙酮和乙醇的峰面积相对标准偏差(n=6)分别为2.2%和2.5%。     

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。