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首页> 外文学位 >Analytical separation methods development: Size-exclusion and reversed-phase liquid chromatography of homopolymer polystyrenes and micellar electrokinetic capillary electrophoresis of the organic constituents of gunshot residues and explosives.
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Analytical separation methods development: Size-exclusion and reversed-phase liquid chromatography of homopolymer polystyrenes and micellar electrokinetic capillary electrophoresis of the organic constituents of gunshot residues and explosives.

机译：分析分离方法的发展：均聚物聚苯乙烯的尺寸排阻和反相液相色谱法以及枪击残留物和炸药的有机成分的胶束电动毛细管电泳。

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摘要

Part I of this study involved the development of a liquid chromatography column for the size-exclusion analysis of macromolecules over a wide range of molecular weights. By using a mixture of silicas containing 80A diameter pores and 500A diameter pores, a column was constructed which provided for the size-exclusion analysis of polystyrene homopolymers from 517 D to 1.8 {dollar}times{dollar} 10{dollar}sp6{dollar} D. This column was then used to study the retention behavior of the polystyrene homopolymers using two different binary mobile phases. It was found that the behavior of the polymers differed in the two mobile-phase systems. It has previously been observed that a transition from low retention to very high retention occurs over a narrow range of mobile phase compositions. In the present study this was found to be true using a mobile phase consisting of CH{dollar}sb2{dollar}Cl{dollar}sb2{dollar}:MeOH. However, using THF:ACN it was possible to measure retention over a wider range of mobile phase compositions. Thus it was found that not only is the retention process for macromolecules dependent on the nature of the molecules, on the nature of the stationary phase, and on the percentage of "good" and "poor" solvents used in the mobile phase, but it is also dependent on the solvents that make up the mobile phase.; Part II of this study demonstrated the use of capillary electrophoresis (CE) for the analysis of samples of interest to forensic scientists. The use of micelles in CE provides an interactive media for analytes that would not otherwise separate under electrophoretic conditions. The organic constituents of gunshot and explosive materials are largely neutral species. By using micellar CE it was possible to effect the separation of 26 of these constituents in under 10 minutes with efficiencies in excess of 200,000 theoretical plates. Four isomers of dinitrotoluene were resolved to the baseline. Detection limits were found to be around 20 pg for the aromatic constituents and around 100 pg for the aliphatic constituents. The method was applied to the analysis of ammunition shell casings, reloading powders, and plastic explosives, resulting in the identification of the various gunshot and explosive constituents making up each sample.
机译：这项研究的第一部分涉及液相色谱柱的开发，该色谱柱用于在宽分子量范围内对大分子进行尺寸排阻分析。通过使用包含80A直径孔和500A直径孔的二氧化硅混合物，构建了一个色谱柱，该色谱柱用于分析聚苯乙烯均聚物从517 D到1.8 {dollar}乘以{dollar} 10 {dollar} sp6 {dollar}的尺寸D.然后，使用该色谱柱研究使用两种不同的二元流动相的聚苯乙烯均聚物的保留行为。发现在两种流动相系统中聚合物的行为不同。先前已经观察到，在窄范围的流动相组成中发生了从低保留到非常高保留的转变。在本研究中，使用由CH {dollar} sb2 {dollar} Cl {dollar} sb2 {dollar}：MeOH组成的流动相发现这是正确的。但是，使用THF：ACN可以在更广泛的流动相组成范围内测量保留度。因此，发现大分子的保留过程不仅取决于分子的性质，固定相的性质以及流动相中使用的“良”和“劣”溶剂的百分比，而且还取决于组成流动相的溶剂。本研究的第二部分展示了毛细管电泳（CE）在法医科学家感兴趣的样品分析中的应用。 CE中胶束的使用为在电泳条件下原本不会分离的分析物提供了一种交互式介质。枪击和爆炸材料的有机成分主要是中性物种。通过使用胶束CE，可以在不到10分钟的时间内分离出26种这些成分，效率超过200,000个理论塔板。将二硝基甲苯的四个异构体解析到基线。芳香族成分的检出限约为20 pg，脂肪族成分的检出限约为100 pg。该方法用于弹药外壳，重装粉末和塑料炸药的分析，从而鉴定出构成每个样品的各种枪弹和炸药成分。

著录项

  • 作者

    Northrop, David Mark.;

  • 作者单位

    Georgetown University.;

  • 授予单位 Georgetown University.;
  • 学科 Chemistry Analytical.
  • 学位 Ph.D.
  • 年度 1991
  • 页码 187 p.
  • 总页数 187
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 化学;
  • 关键词

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