Ultrasensitive Measurement of Estrogens

描述(由申请人提供)：雌激素的测量是为了更好地了解它们在健康和疾病中的作用，特别是乳腺癌。在这个项目中，我们将开发一种超灵敏的方法来测定血清和血浆中的雌激素(雌二醇及其代谢物)。该方法主要包括五个步骤：(1)在稳定的同位素内标物存在的情况下从血清中提取雌激素；(2)通过蒸发、进一步的溶剂分配和/或固相萃取来净化提取物；(3)用电子电话试剂和封顶试剂衍生化雌激素；(4)进行衍生化后的样品清理；(5)用气相色谱-电子捕获飞行时间-飞行时间质谱仪(GC-EC-TOF-MS)检测雌激素的衍生物。该项目的部分工作将涉及制备新的电子电话衍生化试剂，这些试剂有望提供比现有试剂更高的灵敏度来测量雌激素。我们试图在一次程序中测量200亩L血清或血浆中的15种雌激素，其量小至200fg。具有这种性能的方法可以用于测量流行病学研究中的队列样本、绝经后妇女的血清和组织显微活检样本中的雌激素。虽然有必要进行这种分析，但目前的方法对实际样品的灵敏度无法达到这一水平。

DESCRIPTION (provided by applicant): The measurement of estrogens is of interest for a better understanding of their role in both health and disease, especially breast cancer. In this project we will develop an ultrasensitive method for measuring estrogens (estradiol and its metabolites) in serum and plasma. The method will basically consist of five steps: (1) extract the estrogens from serum in the presence of stable isotope internal standards; (2) clean up the extract by evaporation and further solvent partitioning and/or solid phase extraction; (3) derivatize the estrogens with an electrophone reagent and capping reagent; (4) conduct post derivatization sample cleanup; (5) detect the estrogen derivatives by gas chromatography electron capture time-of-flight mass spectrometry (GC-EC-TOF-MS), a technique that has emerged recently. Part of the work in the project will involve the preparation of new electrophone derivatizing agents that are anticipated to provide higher sensitivity than current reagents for measurement of estrogens. We seek to measure 15 estrogens in a single procedure in amounts as small as 200 fg in 200 mu l of serum or plasma. A method with this performance could be used to measure estrogens in cohort samples from epidemiology studies, in serum of postmenopausal women, and in tissue microbiopsy samples. While there is a need for such analysis, the sensitivity of current methods fails to reach this level for real samples.