卷烟主流烟气中芳香胺检测的研究进展

芳香胺被列为卷烟烟气中的有害成分,由于卷烟烟气成分非常复杂,而芳香胺为痕量分析物。为了获得低的检出限和可靠的测定结果,烟气样品需经过富集、提取,衍生、浓缩等前处理,并结合适当的分离和检测仪器才能完成对其中芳香胺的测定。本文介绍了近年来测定卷烟主流烟气中芳香胺的一些研究成果。     

多孔材料降低卷烟烟气中七种有害气体的研究进展

卷烟烟气中含有的7种有害成分是危害人体健康的一大原因。这七种有害气体为羰基化合物﹑α苯并芘﹑亚硝胺﹑CO﹑苯酚﹑氨﹑氢氰酸。近年来,研究者将多孔材料用于烟草吸附有良好的效果。文章综述了各种多孔材料的合成方法和通过在卷烟中添加各种多孔材料对七种有害气体吸附效果的研究进展。     

卷烟主侧流烟气中烟草生物碱的快速测定及对比分析

建立了一种卷烟主测流烟气中生物碱的快速测定方法 ,并应用于多个牌号卷烟烟气的分析比较。该方法将卷烟主侧流烟气收集处理后 ,应用固相微萃取 (SPME)富集并结合GC/MS进样测定其中生物碱的含量 ,具有快速、灵敏、高效、所需样品量少的特点。所得数据对卷烟主侧流烟气成分及特性的研究提供了客观依据     

同时蒸馏萃取和超临界流体萃取研究卷烟主流烟气香气成分

为考察卷烟主流烟气中的香气成分,先用剑桥滤片收集主流烟气的总粒相物,再对同时蒸馏萃取和超临界流体萃取条件进行优化,然后分别采用这两种萃取方法对捕集了烟气粒相物的剑桥滤片进行前处理,再经气相色谱质谱联用仪分析所得样品。结果表明,同时蒸馏萃取得到94种挥发性香气成分,超临界流体萃取得到118种挥发性香气成分,两者共得到香气成分总量达181种。可见,两种方法结合起来分析烟气中香气成分更具优势。     

微粉吸附技术在焙烧炉烟气处理中的研究与应用

传统焙烧烟气净化系统,采用电捕焦油器+湿式脱硫+湿式电除尘的工艺技术路线,该工艺设备使用年限较长,存在着设备腐蚀、电捕冲洗水二次污染、电捕着火、电捕净化效率逐渐降低、维修量大、捕集下来的焦油属于危险废物,难以处理等问题,且该工艺对高致癌物质苯并芘没有好的处理效果,不能实现长期稳定达标排放。而采用微粉吸附技术除去烟气中的颗粒物和沥青烟,同时不再产生固体废物、危险废物,实现环保超低排放的目标。     

热脱附—气相色谱/质谱联用分析卷烟主流烟气主要气相有机化合物

以热脱附法捕集卷烟主流烟气气相成分,利用气相色谱/质谱联用仪对卷烟主流烟气气相成分进行了分析,并以内标为参照,计算卷烟主流烟气主要气相有机化合物的相对释放量。     

卷烟爆珠质量检测研究进展

为了掌握卷烟爆珠质量检测研究现状,从卷烟爆珠安全性指标质量检测、理化指标品质稳定性检测以及对烟气成分影响相关检测研究三个方面进行了综述,并展望未来卷烟爆珠质量检测研究方向。结果表明:1)卷烟爆珠安全性指标质量检测涉及主动添加的着色剂和非主动添加的溶剂残留、增塑剂等的检测,检测方法主要包括液相色谱法(HPLC)及气相色谱-质谱联用法(GC-MS);2)卷烟爆珠品质稳定性主要考察产品物理、化学稳定性,通过检测分析技术与统计学方法相结合的方式进行评价;3)卷烟爆珠对烟气成分影响的研究集中于爆珠中致香成分的迁移率分析、以及对烟气常规组分的作用两个方面,通过分析卷烟爆珠对烟气成分的影响可以用于评价卷烟爆珠对卷烟产品质量的影响。     

聚乳酸纤维滤棒在卷烟中的应用研究

对聚乳酸(PLA)纤维滤棒在卷烟中的应用效果进行了评价,重点分析了PLA纤维滤棒对卷烟烟气中主要酚类物质的过滤效率,并与二醋酸(CA)纤维滤棒进行对比。结果表明:与CA纤维滤棒相比较,采用PLA纤维滤棒后,卷烟烟气中常规成分基本不变,有害成分中亚硝胺释放量略有降低,氢氰酸、巴豆醛和苯酚释放量有一定程度升高,卷烟感官质量有一定程度提升; PLA纤维滤棒对卷烟烟气中酚类物质的过滤效率具有选择性,对烟气中单酚类物质的过滤效率明显高于双酚类物质的过滤效率,且PLA纤维滤棒越长对卷烟烟气中酚类物质的过滤效果越好; PLA纤维滤棒的综合性能接近CA纤维滤棒,作为卷烟滤棒具有良好的应用前景。     

过滤型色谱瓶在离子色谱法测定卷烟主流烟气中氨的应用

为了减少玻璃器皿中钠对检测结果的影响,同时提高卷烟主流烟气中氨含量测定效率,减少卷烟主流烟气中氨含量测定的样品前处理耗时,开发了一种具有过滤功能的、塑料材质的、可用于离子色谱仪自动进样器的色谱瓶。分别采用过滤型色谱瓶和传统过滤装置在相同实验条件下处理参比卷烟样品及商品卷烟样品,实验表明,所得检测结果无显著性差异(Pt0.05)。     

卷烟中添加α-紫罗兰酮对主流烟气挥发性成分影响的研究

为了准确评价香料单体α-紫罗兰酮在卷烟燃吸中对卷烟主流烟气的影响,了解其对卷烟的加香效果,采用吸烟机捕集卷烟抽吸过程中的主流烟气,用GC-MS分析了含有添加剂和空白卷烟主流烟气中的挥发性成分、为α-紫罗兰酮的致香作用提供更加科学的依据,为其在卷烟中的应用提供参考、     

Effect of heat pretreatment and strain rate on tensile properties of polycarbonate sheet

The effects of heat pretreatment and ambient gas (air and vacuum) on selected properties of the polycarbonate sheet have been studied. Changes in tensile properties as functions of heat pretreatment temperature (up to 160°C) and strain rate (wide range of 1.7 × 10^?4 ? 13.1 m/sec = 0.29 ? 2.3 × 10⁴ %/sec) were determined and these are discussed in relation to changes in differential scanning calorimetry (DSC) and gel permeation chromatography (GPC) data. The performance characteristics of the present tensile testing are obtained over a wide range of extension rates without changing the mode of deformation and the shape of the test pieces. It was suggested from the experimental results that heat pretreatment below the glass transition temperature (T_g) causes ordered molecular domains to grow on the free surfaces of the sheet, consisting of thermally deteriorated macromolecules and possessing lower crazing stresses (exhibiting more brittle mechanical responses, leading to the decrease in breaking strain and energy). The effect of annealing above T_g on the tensile properties, and on the results of DSC and GPC, could not be precisely understood.     

离子液体与水混合溶剂应用于微晶纤维素溶剂液化研究

将离子液体氯化1-丁基-3-甲基咪唑（[BMIM]C1）、水、固体酸催化剂组成的混合溶剂应用于微晶纤维素的预处理过程中,并尝试把经过预处理的微晶纤维素应用于随后的溶剂液化的研究中,对经过混合溶剂处理后的微晶纤维素进行表征分析。通过测定纤维素的聚合度、官能团基变化、热重分析、结晶结构和表面结构等对微晶纤维素结构进行比较分析。通过对苯酚溶剂液化的基本表征、残渣物的结晶结构以及生成物相对分子质量的变化了解了混合溶剂对微晶纤维素的处理效果。结果表明,通过混合离子液体[BMIM]C1和水并且添加固体酸催化剂形成新的混合溶剂体系对微晶纤维素进行预处理,发现溶剂在保留纤维素主要葡萄糖单元的同时能够有效地降低聚合度。聚合度从未处理时的190降到样品[B]C1（10）的165和样品[B]C1（10）＋NR50的151。混合溶剂对非结晶或低结晶物质具有一定的溶解能力,并且对高结晶性纤维素部分的氢键结构起到破坏作用和造成整体结晶结构的歪曲。在随后的液化过程中,处理后的纤维素液化效率有所提高,在反应2min时,固体酸加混合溶剂处理的微晶纤维素液化残渣率为19％,而未处理的液化残渣率29％。表明使用了混合溶剂添加固体酸的溶剂体系对加速液化的效果更佳,预处理对最终液化生成物的性质影响不大。     

Carbonization properties of partially hydrogenated aromatic compounds—II: Factors influencing the coke yield in the carbonization of hydrogenated pyrene

Factors influencing the coke yield in the carbonization of hydrogenated pyrenes were investigated from the view of reactivities of their hydrogens. The amount of hydrogen located at 4 ppm in their proton NMR spectrum was found to be intimately related to the coke yield of hydrogenated pyrenes. Oxidative pretreatment at 150°C significantly increased the coke yield. The structural changes of hydrogenated pyrenes by oxidative pretreatment were investigated by means of GPC, IR and NMR. The scheme of oligomerization as the first step of carbonization is discussed in connection with the reactivities of hydrogens in hydrogenated pyrenes.     

The surface modification of medical polyurethane to improve the hydrophilicity and lubricity: The effect of pretreatment

The medical polyurethane (PU) film was grafted with poly(acrylic acid) (PAA) to improve the hydrophilic and lubricious properties. The influences of pretreatment by ozone or potassium peroxydisulfate on themorphologies of PU films and grafting results were systematically investigated. The grafted PU films were characterized using attenuated total reflection Fourier transformed infrared spectroscopy (ATR‐FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM) and gel permeation chromatography (GPC). The hydrophilic and lubricious properties were evaluated by water contact angle and friction coefficient, respectively. The results showed that PAA could be grafted firmly on PU activated by both ozone and potassium peroxydisulfate, and the PAA‐grafted PU showed good hydrophilic and lubricious performance. More importantly, the PAA‐grafted PU films with the pretreatment of ozone were better in surface roughness, hydrophilicty and lubricity, compared to those with the pretreatment of potassium peroxydisulfate. Hence, surface ozonation could be a better choice for the pretreatment of medical polymer. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

GPC技术在合成纤维相对分子质量及其分布测试中的应用

综述了凝胶渗透色谱(GPC)技术在腈纶、涤纶、聚酰亚胺纤维、氯纶、氨纶、尼龙纤维和聚乙烯醇纤维的相对分子质量及其分布测试中的应用的研究进展。重点对各合成纤维的GPC测试条件进行了总结,揭示了色谱条件的优化机理,并对GPC方法开发方向及在合成纤维工业中的进一步应用提出了建议。指出在以后的合成纤维生产和研究过程中,可以挖掘GPC的更多用途,如将GPC与多检测器联用或作为多维色谱的一部分,以获得更多的结构-性能信息,明确制备工艺的关键质量控制指标,为合成纤维的生产提供新方法与新思路。     

GPC characterization for assessing compatibility problems with heavy fuel oils

Precipitation of solids is one of the major problems associated with the shipping and handling of heavy residual oils especially No. 6 heating oil. ASTM specifications which currently include viscosity, flash point and pouring point are not adequate to predict the handling problems. The residual oils are becoming more complex in composition due to modern refinery techniques for cracking the heavier residues into distillable fractions. In this study, several heating oil samples, including a sample which partially solidified during transport, were analyzed using various techniques including separation by gel permeation chromatography (GPC), vacuum distillation, separation of petroleum asphaltenes by ASTM method, elemental analysis and proton and ¹³C NMR spectroscopy. The distillable species in the fraction separated by GPC were characterized by high resolution gas chromatography—mass spectroscopy (GC—MS). The study showed that the GPC can be used as a reliable technique for the analysis of heavy residual oils. The GPC separation of No. 6 heating oil gave three fractions enriched with chemically distinct species. The first fraction was composed of heavy molecular species generally known as asphaltenes. The second fraction was mostly straight chain paraffins. The third fraction was composed of low molecular weight aromatics. Although occasional verification of GPC data by GC—MS and by NMR spectroscopy is desirable, the GPC alone is an efficient analytical tool for evaluating the composition as well as predicting the handling problems associated with shipping and storage of various residual oils.     

Chloride-induced corrosion of reinforcement in low-calcium fly ash-based geopolymer concrete

Geopolymer concrete (GPC) has significant potential as a more sustainable alternative for ordinary Portland cement concrete (PCC). However; as a rather new engineering material, there are some concerns over the durability aspects of geopolymer-based binders. In this study, the performance of chloride-contaminated reinforced GPC specimens manufactured using a blended low-calcium fly ash and slag cement is investigated by long-term monitoring of corrosion parameters such as open circuit corrosion potential, polarization resistance and Tafel slopes. The electrochemical results are validated by contrasting the electrochemical mass losses with the mass losses obtained from the gravimetric measurements. The investigated low-calcium fly ash-based GPC exhibit a comparable electrochemical performance to a similar strength PCC during the propagation phase of corrosion. Additionally, some of the conventional classifications which are commonly used to assess the severity of corrosion in Portland cement-based corroding systems might need some recalibration to be used for low-calcium fly ash-based corroding systems.     

Adaptive generalised predictive control of high purity internal thermally coupled distillation column

Internal thermally coupled distillation column (ITCDIC) is a frontier in the energy‐saving distillation researches. One of the bottlenecks to prevent the column from being commercialised is the difficulty in control design due to the high sensitivity to disturbances, strong asymmetric nonlinearity and inverse response especially under high purity. An adaptive multivariable generalised predictive control (AM‐GPC) strategy of ITCDIC process is proposed to solve the difficulties in high purity. The simulation results of AM‐GPC are compared with single input and single output GPC (S‐GPC), multivariable GPC (M‐GPC), modified IMC (M‐IMC) and traditional PID control in detail. The performances confirm the accuracy and validity of AM‐GPC for the high‐purity ITCDIC process. © 2011 Canadian Society for Chemical Engineering     

Fractionation of Linear Polyethylene with Gel Permeation Chromatography. Part III

Abstract

Many commercial linear polyethylenes have very broad distributions of molecular weight. The high molecular weight fractions often extend beyond the highest molecular weight calibration standard of GPC. For this reason the reliability of information obtainable from GPC has been examined with attention to the average molecular weights. Calibration range is a serious limitation for the accurate determination of the - weight-average and the higher averages of molecular weight. Uncertainty in the baseline at the high molecular weight region, however, does not produce a significant error. With a four-column GPC having 10³ to 10⁷ A nominal capacity, improved resolution is needed in the high molecular weight range. In order to examine the resolution and to improve the calibration, a polyethylene standard of ca. 3–4 million molecular weight is required. With the present limitation of GPC the greatest amount of information can be obtained by examining and intercomparing the cumulative distribution curves. With this representation ca. 95% or more of the cumulative weight range is free from uncertainty in calibration and resolution. A question is raised as to whether melt index is precisely a function of the weight-average molecular weight. This question is pertinent when significantly different molecular weight distributions are involved. GPC offers an opportunity to resolve the question.     

甘油磷酰胆碱的分析、制备及纯化研究进展

甘油磷酰胆碱（GPC）作为重要神经递质乙酰胆碱的生物合成前体,能够促进乙酰胆碱在脑部的合成,增强人体的记忆力和认知能力,预防老年痴呆类疾病,已引起医药界的高度关注。为进一步促进GPC相关产品的研究与应用,本文重点介绍了近几年GPC的分析、制备及纯化技术的研究进展,并比较了不同方法的优缺点。指出高效液相色谱法（HPLC）是分析GPC的主流方法,但没有一种检测器能检测到所有关键的杂质,需要多种检测器联用才可判断GPC的质量是否达到要求。全化学合成和水解卵磷脂（PC）是制备GPC的主要方法。文中指出全化学合成法具有收率高、产品纯度高和制备工艺完善的优点,但起始原料昂贵,全化学合成的GPC中会残留基因毒性杂质,严重影响产品品质。水解PC法能够制备出食品级GPC,所得产品无毒无害,但水解法收率低,产品纯度低,纯化难度大,难以规模化生产。结晶法和柱色谱法是纯化GPC粗品的主要方法。结晶法得到的产品纯度高,但收率低,生产成本高。柱色谱法能除去大量杂质,除杂效果好,但生产过程中会产生大量“三废”,纯化周期长。文中分析表明,HPLC和多种检测器联用是定量分析GPC及其相关杂质的最有效方法,水解PC以制备食品级GPC是如今的研究热点,开发出高效的纯化技术是工业化生产GPC的关键和难点。