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New developments on high-resolution luminescence spectroscopy and their application to the direct analysis of organic pollutants in environmental samples.

机译：高分辨率发光光谱学的新进展及其在环境样品中有机污染物直接分析中的应用。

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摘要

Polycyclic aromatic compounds (PACs), which comprise a complex class of condensed multi-ring benzenoid compounds, are important environmental pollutants originating from a wide variety of natural and anthropogenic sources. PACs are generally formed during incomplete combustion of pyrolisis of organic matter containing carbon and hydrogen. Because combustion of organic materials is involved in countless natural processes or human activities, PACs are omnipresent and abundant pollutants in air, soil, and water. Chemical analysis of PACs is of great environmental and toxicological importance. Many of them are highly suspect as etiological agents in human cancer. Because PACs carcinogenic properties strongly depend on molecular structure and differ significantly from isomer to isomer, it is of paramount importance to determine the most toxic isomers even if they are present at much lower concentrations than their less toxic isomers. Gas chromatography (GC), high-resolution GC, and high-performance liquid chromatography (HPLC) are the basis for standard PACs identification and determination. Many cases exist where GC, HPLC, and even HR-GC have not been capable to provide unambiguous isomer identification. The lack of reliable analytical data has lead to serious errors in environmental and toxicological studies.; This dissertation deals with the development of novel instrumentation and analytical methods for the analysis of PACs in environmental samples. The developed methodology is based on two well-known high-resolution luminescence techniques, namely Shpol'skii Spectroscopy (SS) and Fluorescence Line Narrowing Spectroscopy (FLNS). Although these two techniques have long been recognized for their capability in providing direct determination of target PACs in complex environmental samples, several reasons have hampered their widespread use for the problem at hand. These include inconvenient sample freezing procedures; questions about signal reproducibility; lengthy spectral acquisition, which might cause severe sample degradation due to prolonged excitation; broadband fluorescence background that degrades quality of spectra, precision of measurements and detection limits; solvent constrains imposed by the need of optically transparent media; and, most importantly, the lack of selectivity and sensitivity for unambiguous determination of closely related PACs metabolites. This dissertation presents significant advances on all fronts.; The analytical methodology is then extended to the analysis of fluoroquinolones (FQs) in aqueous samples. FQs are one of the most powerful classes of antibiotics currently used for the treatment of urinary tract infections. Their widespread use in both human and animal medicine has prompted their appearance in aquatic systems. The search for a universal method capable to face this new environmental challenge has been centered on HPLC. Depending on the FQ and its concentration level, successful determination has been accomplished with mass spectrometry, room-temperature fluorescence (RTF) or UV absorption spectrometry. Unfortunately, no single detection mode has shown the ability to detect all FQ at the concentration ratios found in environmental waters. We provide a feasible alternative based on FLNS.; On the instrumentation side, we present a single instrument with the capability to collect multidimensional data formats in both the fluorescence and the phosphorescence time domains. We demonstrate the ability to perform luminescence measurements in highly scattering media by comparing the precision of measurements in optically transparent solvents (Shpol'skii solvents) to those obtained in "snow-like" matrixes and solid samples. For decades, conventional low-temperature methodology has been restricted to optically transparent media. This restriction has limited its application to organic solvents that freeze into a glass. In this dissertation, we remove this limitation with the use of cryogenic fiber-opt
机译：多环芳族化合物（PAC）包含一类复杂的稠合多环苯并类化合物，是重要的环境污染物，其源于多种自然和人为来源。 PAC通常是在不完全燃烧包含碳和氢的有机物的热解过程中形成的。由于有机材料的燃烧涉及无数的自然过程或人类活动，因此PAC是无处不在的，并且在空气，土壤和水中都是丰富的污染物。 PAC的化学分析具有重要的环境和毒理学重要性。他们中的许多人被认为是人类癌症的病因。由于PAC的致癌特性在很大程度上取决于分子结构，并且异构体之间存在显着差异，因此即使毒性最高的异构体比毒性较低的异构体低得多，确定毒性最高的异构体也至关重要。气相色谱（GC），高分辨率GC和高效液相色谱（HPLC）是标准PAC鉴定和确定的基础。在许多情况下，GC，HPLC甚至HR-GC都无法提供明确的异构体鉴定。缺乏可靠的分析数据导致在环境和毒理学研究中的严重错误。本文研究了新型的仪器和分析方法用于环境样品中PAC的分析。所开发的方法基于两种众所周知的高分辨率发光技术，即Shpol'skii光谱（SS）和荧光线窄光谱（FLNS）。尽管这两种技术早已被公认具有直接测定复杂环境样品中目标PAC的能力，但有几个原因阻碍了它们广泛用于当前问题。这些措施包括不方便的样品冷冻程序；有关信号再现性的​​问题；较长的光谱采集，可能由于长时间的激发而导致严重的样品降解；宽带荧光背景会降低光谱质量，测量精度和检测限；由于需要光学透明介质而施加的溶剂限制；最重要的是，缺乏明确确定紧密相关的PAC代谢物的选择性和敏感性。本文提出了各个方面的重大进展。然后将分析方法扩展到分析水性样品中的氟喹诺酮类（FQ）。 FQ是目前用于治疗尿路感染的最强大的抗生素类别之一。它们在人类和动物医学​​中的广泛使用促使它们出现在水生系统中。寻找能够应对这一新的环境挑战的通用方法的重点是HPLC。根据FQ及其浓度水平，已经成功地通过质谱，室温荧光（RTF）或UV吸收光谱法进行了测定。不幸的是，没有单一的检测模式能够以环境水域中的浓度比检测所有FQ。我们提供基于FLNS的可行替代方案。在仪器方面，我们提出了一种能够在荧光和磷光时域中收集多维数据格式的仪器。通过将光学透明溶剂（Shpol'skii溶剂）中的测量精度与“雪状”基质和固体样品中获得的测量精度进行比较，我们证明了在高散射介质中执行发光测量的能力。几十年来，常规的低温方法一直局限于光学透明的介质。该限制将其应用限制在冻结到玻璃中的有机溶剂中。在本文中，我们通过使用低温光纤来消除这一限制。

著录项

  • 作者

    Yu, Shenjiang.;

  • 作者单位

    University of Central Florida.;

  • 授予单位 University of Central Florida.;
  • 学科 Chemistry Analytical.
  • 学位 Ph.D.
  • 年度 2006
  • 页码 209 p.
  • 总页数 209
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 化学;
  • 关键词

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