ISOTOPE RATIO MONITORING MASS SPECTROMETER

华盛顿大学光谱分析设施的功能是 地方、地区、国家和国际的群众资源 自1969年我们的第一台仪器投入使用以来 手术。在其间的几年里，该设施已经发展到 包括5台四极GCMS仪器、1台LC MS仪器、1台质量 选择性探测器，双聚焦扩展质量范围 仪器和自动同位素比对系统。在最后一次 年，该设施记录的实际仪器时间为7810小时 样本分析。 据我们所知，我们是唯一的NIH质谱学资源 提供常规、高稀释、高精度、双进双出. 生物医学界的收集器同位素比率分析。这个 用于此目的的工具是用当地资金购买的 以“最小”配置。因为，在当时，没有 商业上可获得的自动IRMS机器、自动化和 该装置实现了仪器的软件控制。 由于最初的制造商设计/施工缺陷，这 仪器从未在预期的规格和范围内运行 总是受到不可接受的“停机时间”的影响。此外， 因为开发硬件和软件的个人 这个仪器现在已经让资源，它变成了 要保持这一“非标准”越来越难 仪器面对不断增加的、沉重的样品负载。 我们正在请求支持以购买当前的、自动的同位素 比率仪器与制造商的数据系统，以允许我们 继续为国家用户群体提供综合信息管理系统服务。 此外，由于a)当前发展的很大一部分 在人类稳定同位素示踪动力学方面的工作涉及前体- 产品关系，b)传统的GCMS通常不 灵敏度足以测量产品的同位素丰度，而不需要 在前驱体内产生“非示踪”质量微扰效应 C)IRMS需要困难的样品制备才能获得 IRMS同位素分析所需的高纯度产品，我们是 请求GC/Burning/IRMS接口以实现简便性 生物样品中产物同位素丰度的测定 稀释度高于常规离子的稀释度 监测GCMS。

The Washington University Spectrometry Facility has functioned as a local, regional, national, and international resource for mass spectrometry since 1969 when our first instrument was put into operation. In the intervening years, the facility has grown to include 5 quadrupole GCMS instrument an LCMS instrument, a mass selective detector, a double focusing extended mass range instrument, and an automated isotope ratio system. In the last year, this facility logged 7810 hours of instrument time for actual sample analysis. To our knowledge, we are the only NIH Mass Spectrometry Resource providing routine, high dilution, high precision, dual-inlet dual- collector isotope ratio analyses to the biomedical community. The instrument used for this purpose was purchased with local funds in a "minimal" configuration. Since, at the time, there were no commercially available automated IRMS machines, automation and software control of the instrument was implemented in the facility. Because of initial manufacturer design/construction flaws, this instrument has never functioned within expected specifications an has always been subject to unacceptable "down time". Further, since the individual who developed the hardware and software for this instrument has now let the resource, it has become increasingly more difficult to maintain this "non-standard" instrument in the face of an increasing, heavy sample load. We are asking for support to purchase a current, automated isotope ratio instrument with the manufacturer's data system to allow us to continue to provide IRMS services to the national user's group. In addition, since a) a significant fraction of current development work in human stable isotope tracer kinetics involves precursor- product relationships, b) conventional GCMS is generally not sensitivity enough to measure product isotope enrichments without producing "non-tracer" mass perturbation effects in the precursor pool, and c) IRMS requires difficult sample preparation to obtain the highly pure product required for IRMS isotopic analyses, we are requesting a GC/combustion/IRMS interface to allow facile determination of product isotopic enrichments in biological samples at dilutions higher than those possible by conventional ion monitoring GCMS.