离子色谱法测定卷烟主流烟气中的气相氨北大核心CSCD

采用离子色谱法测定卷烟主流烟气中的气相氨。采用IonPac CS16阳离子分析柱和IonPac CG16阳离子保护柱,以0.045mol·L-1甲烷磺酸为淋洗液,电导检测器进行检测。气相氨的的质量浓度在0.01~1.0mg·L-1范围内呈线性,其检出限(3s)和测性下限(10s)分别为8.79×10-3μg·支-1和2.93×10-2μg·支-1。加标回收率在92.2%~103%之间,日内、日间相对标准偏差(n=5)均小于5.5%。采用此方法对七种卷烟主流烟气中气相氨的释放量进行了测定。     

主流烟气中甲胺和乙胺离子色谱法测定

建立了用0.01 mol·L-1盐酸水溶液吸收,离子色谱法测定卷烟主流烟气中甲胺和乙胺的方法。该方法采用Ion Pac CS16(4×250 mm)分离柱和CG16(4×50 mm)保护柱,10mmol·L-1甲烷基磺酸(MSA)水溶液等梯度洗脱,在柱温60℃、流速1.0 m L·min-1的条件下,实现了甲胺和乙胺的有效分离。方法的线性关系良好,RSD均小于5%,甲胺检出限为0.04μg/支,加标平均回收率为92.7%~94.3%,乙胺检出限为0.05μg/支,加标平均回收率为93.5%~103.0%。该方法灵敏度高、准确性好、前处理简单,有良好的可靠性和实用性。     

离子色谱法测定卷烟烟气中氨

用离子色谱法测定卷烟主流烟气中氨。选取同一包装中的卷烟,按行标YC/T 29-1996的规定用吸烟机抽吸。用剑桥滤片捕集卷烟烟气粒相部分,将所得滤片用0.005 mol.L-1盐酸溶液提纯。用0.005 mol.L-1盐酸溶液吸收卷烟烟气气相部分。将两份盐酸溶液合并后再通过装填有MCI-GEL反相树脂的固相萃取柱除去焦油和烟碱类物质,然后用离子色谱测定氨。方法的检出限(3S/N)为0.006 mg.L-1。在吸烟所得提取液中的加标回收率在95.6%~102.5%之间。试样平行7次测定的相对标准偏差为3.1%。方法用于10种品牌卷烟中氨的测定,氨量范围为7.62~14.0μg.支-1。     

超声萃取-气相色谱-质谱法测定卷烟主流烟气中的6种挥发酚

采用气相色谱-质谱法测定卷烟主流烟气中的苯酚、对甲酚、间甲酚、邻甲酚、对苯二酚和间苯二酚等6种挥发酚的含量。用剑桥滤片在标准抽吸条件下采集5支卷烟烟气粒相物,用甲醇超声萃取10min。所得萃取液用DB-624毛细管色谱柱(30m×0.25mm,1.4μm)为固定相进行分离,在质谱分析中采用全扫描和选择离子监测模式。以苯酚-D_5为内标物。方法的检出限(3S/N)在10~16ng·支~(-1)之间,测定下限(10S/N)在28~40ng·支~(-1)之间。加标回收率在84.6%~99.1%之间,测定值的相对标准偏差(n=6)在2.1%~6.4%之间。     

离子色谱法同时测定卷烟主流烟气中氨和烟碱的含量

建立离子色谱仪同时测定卷烟主流烟气中氨和烟碱含量的方法。对样品前处理条件和色谱分离条件进行了优化,最终选择10 mmol/L盐酸作为气相捕集液和总粒相物的萃取液,在梯度淋洗条件下使用电导检测器进行测定,色谱柱为CS17阳离子分析柱,检测温度为40℃。方法学考察表明,氨和烟碱标准工作曲线线性相关系数分别为0.999 8和0.999 9,检出限分别为0.31μg/支和22μg/支。氨和烟碱测定结果的相对标准偏差分别为1.86%,2.23%(n=5),氨加标回收率在98.8%~104.9%之间,烟碱加标回收率在96.7%~103.1%之间。该方法能有效去除干扰,方法可操作性强,可同时测定卷烟主流烟气中多种成分。     

连续流动法测定卷烟侧流烟气中的氨

建立了用稀硫酸溶液吸收—连续流动法测定卷烟测流烟气中氨的方法。通过对吸收条件、精密度、稳定性和加标回收率的全面考察,结果表明:1在2~30μg·m L-1范围内方法具有良好的线性关系(R2=0.9994),,加标回收率在95.74%~107.32%之间,RSD小于3%,方法的检测限为1.45μg/支;2侧流烟气中氨的释放量是主流烟气中的数百倍,且其主要存在于气相部分;3该方法快速准确,重复性好,适合卷烟侧流烟气中氨的大批、快速测定。     

离子色谱法测定博物馆室内空气中氨的含量

对比了Dionex IonPac CS12A和IonPac CS16两种阳离子色谱柱的分离特性,通过优化色谱条件,使两种色谱柱分别适用于被动法和主动法空气采样分析。根据铵为弱碱性阳离子发生不完全电离的特点,提出了离子色谱法测定博物馆室内空气中氨浓度的方法。绘制了低浓度和高浓度两条标准曲线,线性范围分别为0.01~0.50 mg.L-1和0.50~5.00 mg.L-1,被动法采样法得氨的检出限(3S/N)为0.9μg.L-1,回收率在97.2%~105.7%之间;主动法采样法得氨的检出限(3S/N)为1.6μg.L-1,回收率在102.8%~104.7%之间。     

离子色谱法测定电子烟烟液中氨的含量

建立了测定电子烟烟液中的氨含量离子色谱法。样品经10 mol·L-1盐酸溶液萃取10 min后,采用Dionex Ion Pac CS16A阳离子交换柱分离,以MSA为淋洗液进梯度洗脱,用电化学检测器检测。氨的质量浓度在0.05~1.0 mg·L-1范围内与峰面积呈线性关系,检出限(3S/N)为0.035μg·g-1,测定下限(10S/N)为0.12μg·g-1。方法用于12种市售品牌电子烟烟液中氨的测定,加标回收率在93.2%~106%之间,测定值的相对标准偏差(n=5)小于4%。     

超低温溶剂提取-全二维气相色谱/飞行时间质谱法测定卷烟主流烟气中有机酸成分

建立了超低温溶剂提取结合全二维气相色谱/飞行时间质谱(GC×GC-TOF/MS)测定卷烟主流烟气中有机酸类成分的方法。首先利用乙醚为提取溶剂的超低温溶剂提取装置对卷烟主流烟气进行捕集,然后将提取液通过液液萃取、N,O-双(三甲基硅烷)三氟乙酰胺(BSTFA)衍生化后,以DB-1(30 m×0.25 mm,1.0μm)为一维色谱柱、DB-wax(1.5 m×0.1 mm,0.1μm)为二维色谱柱组成的柱系统对目标物进行分离,在调制周期为6 s、质量扫描范围为m/z 45~450的条件下,卷烟主流烟气中12种有机酸成分可以在58 min内得到准确的检测。实验结果表明,卷烟主流烟气中12种有机酸标准曲线相关系数R2>0.99,加标回收率为80.2%~107.8%,相对标准偏差(RSD)的范围为0.4%~12.1%(n=5),方法检出限为1.3~24.5μg/kg,定量限为4.1~77.1μg/kg。     

卷烟主流烟气气相水分的捕集及气相色谱法测定

提出了用剑桥滤片捕集烟气粒相物,以异丙醇和乙醇为吸收液、两级碰撞捕集器串联捕集烟气气相物,用气相色谱法测定主流烟气粒相和气相水分含量的方法。试验结果表明:线性范围为0.8～6.0g.L-1,相对标准偏差(n=5)小于2.5%之间,回收率为93.46%～106.15%。采用该法对7种卷烟主流烟气中粒相和气相水分进行测定,烟气总水分含量为6.77～9.43mg.支-1,其中气相水分约占总水分的65%～75%,表明气相水分是研究卷烟品质的重要参数。     

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。     

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.     

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。     

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。