SELECTIVE/SENSITIVE ANALYSIS OF ANABOLIC STEROIDS

在这个应用中，我们提出了选择性和可选性的发展 尿液中合成代谢物质定量分析的灵敏方法 类固醇。该方法将基于电子捕获负片 样品电离(ECNI)或电子轰击质谱学 用气相色谱进样器进样。该计划的一个主要推动力 建议是基于将分析物转化为 亲电物种通过氧化反应转化为 结构。一种平行的方法是将亲电基团添加到 通过更传统的衍生化反应得到母体结构。 初步实验表明，氧化法允许 检测中对生化本底的显著区分 生物样品基质中的地塞米松；这些实验还 表现出异常高的ECNI响应来自选定的 氧化修饰的类固醇。 该提案包括两个主要部分。第一个将利用 ECNI质谱学的分析优势通过评估 传统的衍生化方法以及氧化 用于分析的合成类固醇的制备方法的改进。在……里面 与本实用研究同时进行的分析物修饰的目的 在发展定量分析的同时，我们还将追求一个基本的 研究结构与ECNI反应的关系。这项调查 涉及模型化合物将有助于理解基础 对于电子俘获截面的急剧增加， 某些类固醇结构。这两个部分的其他努力 拟议的工作将涉及化学氧化的最优化。 条件，简化样品的处理，制备和 对合适的内部标准进行评估，并对 开发方法学的初步结果。成功 完成结构VS基础研究中提出的工作 ECNI的回应将使人们更好地理解 为合理推广电子俘获过程提供了依据 ECNI分析方法学适用于更大范围的生物医学化合物 重要性。

In this application, we propose the development of selective and sensitive methodology for the quantitative analysis of urine for anabolic steroids. The methodology will be based on electron capture negative ionization (ECNI) or electron impact mass spectrometry with sample introduction by gas chromatographic inlet. A major thrust of the proposal is based on the novel strategy of transforming the analyte to an electrophilic species via an oxidation reaction to a transformed structure. A parallel approach involves adding electrophilic moieties to the parent structure via more conventional derivatization reactions. Preliminary experiments have shown that the oxidative approach permits remarkable discrimination against biochemical background in the detection of dexamethasone in a biological sample matrix; these experiments also have demonstrated an unusually high ECNI response from selected oxidatively modified steroids. The proposal consists of two major parts. The first will exploit the analytical advantage of ECNI mass spectrometry by assessing both the conventional derivatization approach as well as the oxidative modification approach to prepare the anabolic steroids for analysis. In parallel with this practical study of analyte modification for purposes of developing a quantitative assay, we also will pursue a fundamental investigation of structure vs ECNI response. This investigation involving model compounds will be directed toward understanding the basis for the dramatic increase in the electron-capture cross section of certain steroid structures. Other efforts in these two parts of the proposed work will involve optimization of the chemical oxidation conditions, simplification of sample processing, preparation and evaluation of suitable internal standards, and statistical evaluation of preliminary results from the developing methodologies. Successful completion of the work proposed in the fundamental study of structure vs ECNI response will lead to a greater understanding of the electron-capture process and provide a basis for rationally extending ECNI analytical methodology to a larger scope of compounds of biomedical importance.