液液萃取-气相色谱-质谱联用法同时检测烟用水基胶中的23种酯类化合物

建立了一种同时检测烟用水基胶中23种酯类化合物的液液萃取-气相色谱-质谱联用方法。23种酯类化合物包括乙酸酯类、丙烯酸酯类、甲基丙烯酸酯类、邻苯二甲酸酯类化合物。水基胶样品经水分散后,用含内标物丙酸苯乙酯的正己烷溶液振荡萃取,萃取液离心后过0.45 μm有机相滤膜,用DB-WAXETR气相色谱柱(60 m×0.25 mm×0.25 μm)分离,质谱选择离子模式监测,内标法定量。结果表明,23种酯类化合物在0.4~50.0 mg/L范围内线性关系良好,线性相关系数大于0.998,样品加标回收率为81.8%~109.1%,相对标准偏差(RSD, n=5)小于4%,检出限为0.02~0.76 mg/kg,定量限为0.04~2.52 mg/kg。该方法前处理简便、快速、分析时间短、灵敏度高、重复性好,可用于烟用水基胶中23种酯类化合物的同时检测。     

顶空-气相色谱法测定烟用水基胶中乙酸乙烯酯的残留量

采用顶空-气相色谱法测定烟用水基胶中乙酸乙烯酯的残留量。以N,N-二甲基甲酰胺为基质校正剂、正丙醇为内标,通过顶空进样后,采用HP-VOC色谱柱分离,火焰离子化检测器(FID)检测。乙酸乙烯酯的质量浓度在0.51~50mg·L-1范围内呈线性,方法的检出限(3S/N)为0.82μg·g-1。方法用于不同烟用水基胶中乙酸乙烯酯残留量的测定,加标回收率在96.2%~101%之间,测定值的相对标准偏差(n=6)小于3%。     

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。     

固相萃取-超高效液相色谱法测定烟用水基胶中丙烯酰胺

建立了采用固相萃取-超高液相色谱/紫外检测测定烟用水基胶中丙烯酰胺的分析方法。样品经超纯水进行超声提取,固相萃取柱进行富集净化后,经HSS T3色谱柱分离,以甲醇和水为流动相等度洗脱,紫外检测,外标法定量。结果显示,丙烯酰胺在浓度0.01~20.0μg·mL-1范围内有良好的线性关系,相关系数为0.9999。丙烯酰胺三个不同浓度的加标回收率为91.7%~105.1%;相对标准偏差为1.3%~4.7%(n=6);检出限为3.5μg·L-1。该方法分析时间短、结果准确可靠,满足烟用水基胶中丙烯酰胺的测定。     

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%。     

超高效液相色谱-串联质谱法测定烟用水基胶中邻苯二甲酸酯类化合物

建立了一种测定烟用水基胶中17种邻苯二甲酸酯类(PAEs)化合物的超高效液相色谱-串联质谱(UPLC-MS/MS)法。样品经水分散,以甲醇定容,涡旋振荡萃取。萃取液离心后,过有机相滤膜进行UPLC-MS/MS分析。通过增加延时柱的方法,排除色谱系统带入的PAEs干扰。结果表明:在0~5μg/m L范围内,方法的线性关系良好,相关系数均大于0.994,定量下限为0.010~0.479μg/g。该方法的回收率为87.6%~106.0%,相对标准偏差(RSD,n=6)为0.8%~6.2%。将该方法与YC/T 333-2010标准方法进行对比,结果显示两种方法的检测数据不存在显著性差异。方法用于烟用水基胶中17种PAEs的测定,操作简单,稳定性好。     

超高效液相色谱-飞行时间质谱法测定水基胶中甲醛

本文建立了超高效液相色谱-飞行时间质谱法(UPLC-TOF MS)测定水基胶中甲醛含量的分析方法。水基胶用去离子水进行振荡提取,经2,4-二硝基苯肼衍生后,衍生物直接用UPLC-TOF MS法检测。结果表明,检测甲醛的线性范围在0.0746~8.93mg/L之间,线性相关系数r2=0.9990,检出限为0.5mg/kg,平均加标回收率范围为94.43%~105.27%。样品重复8次测定的相对标准偏差(RSD)均小于10%。该方法灵敏度高、重复性好、定量准确,满足水基胶中甲醛的检测要求。     

磁性石墨烯分散固相萃取结合液相色谱-串联质谱法测定水基胶中的双酚A和烷基酚

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)与磁性石墨烯相结合测定水基胶中双酚A、壬基酚和辛基酚的方法。样品提取后,以磁性石墨烯分散固相萃取净化,经BEH C18色谱柱分离。分析物的回收率在81.5%～97.9%之间,日间相对标准偏差(RSDs)小于8.0%。所有化合物均获得了良好的线性系数(r≥0.9996),检出限(LOD)和定量限(LOQ)范围分别为3～8μg/kg和10～26μg/kg。采用该方法对20个水基胶实际样品进行检测,仅有1个样品检出4-正壬基酚。该方法可用于测定水基胶中双酚A和4种烷基酚的含量。     

酶解-高效液相色谱法检测麦片和啤酒中β-葡聚糖的含量

用纤维素酶将样品提取液中的β-葡聚糖酶解为葡萄糖,高效液相色谱-示差折光检测葡萄糖,从而确定样品中β-葡聚糖的含量.0.1g粉碎后的麦片用1mL80%乙醇洗涤,5mL 水提取,检测提取液中β-葡聚糖的含量.用该方法检测标准物质大麦,回收率大于72.0%,相对标准偏差为2.5%,检出限为2%.10mL 啤酒样品用40mL95%乙醇沉淀,离心,沉淀物于80℃烘干,用1.8mL水溶解,测定溶液中β-葡聚糖的含量.啤酒中β-葡聚糖的检出限为40mg/L.方法可对大麦和啤酒中β-葡聚糖含量进行检测.     

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     

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.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

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。     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

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.

     

Investigation of Kinetics of Solid-Phase Synthesis of Lithium Orthosilicate

The kinetics of the interaction between lithium carbonate and silica with various degrees of dispersion was investigated by TG and DTA methods. It was found that the utilization of pyrogenic silica with a specific surface area of about 300 m²g^-1 instead of aerosil with one of 175 m²g^-1 leads to an increase of the reaction rate between lithium carbonate and silica, which depends on the formation and growth of lithium orthosilicate crystals in the first stage, and is conditioned by the diffusion of lithium and oxygen ions through the lithium orthosilicate layer formed at temperatures above 800 K. This supposition is supported by the kinetic analysis results obtained with the use of the different models. The optimal regime of heating is recommended. This revised version was published online in July 2006 with corrections to the Cover Date.     

小环化合物中饱和碳质子化学位移的计算

小环化合物由于其张力、构型、构象和各向异性效应等原因,环碳上质子化学位移缺乏规律性,难以预测,对此作者曾提出一种近似算法。本文根据303种小环化合物中饱和碳质子的化学位移实验数据,将适于计算这类质子化学位移的公式表述为:     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.