SBIR Phase II: A Compact Accelerator Mass Spectrometer for the Analysis of Biological Samples

*9634259 Klinkowstein这个小型企业创新研究第二阶段项目将开发一种紧凑、低成本的加速器质谱学系统，用于测量标记生物样品中超低数量的碳-14和氚。该仪器的灵敏度将比液体闪烁衰变计数器高100-1000倍，并将允许测量当代样品中处于或低于自然发生水平的碳14浓度。AMS提供的高灵敏度允许在极低水平的暴露下在分子水平上研究环境致癌物、诱变剂和毒素的去向。现有的AMS系统使用大型、昂贵的核物理加速器，生物医学研究人员通常无法获得这些加速器，并且与用于提纯生物样品的标准色谱仪的接口不兼容。这项研究旨在开发一种专用的生物医学AMS系统，该系统基于一种新的方法，允许加速器能量与现有系统相比降低约三倍。这极大地降低了仪器的尺寸、成本和复杂性。这一方法的可行性在第一阶段实验中得到了证明，这表明使用1 mV串联加速器的AMS系统将允许在标记的当代样品中明确地检测14C。第二阶段的研究将集中在生物医学AMS的第一个在线样品纯化和注射接口的建设和测试。该接口将使直接将生物样品从气相色谱仪引入AMS系统成为可能，从而使AMS与标准的高分辨率化学分离技术结合使用。该系统将为专用的低能量AMS仪器提供关键的前端技术，并将使任何现有的AMS系统用于生物样本的在线分析成为可能。该系统将对研究和分析实验室研究环境致癌物和遗传毒素的生物效应很有意义。***

*** 9634259 Klinkowstein This Small Business Innovation Research Phase II project is to develop a compact, low cost accelerator mass spectrometry (AMS) system for the measurement of ultra-low quantities of carbon-14 and tritium in labeled biological samples. The instrument will have a sensitivity 100-1000 times higher than that of liquid scintillation decay counters and will allow the measurement of carbon-14 concentrations at or below naturally occurring levels in contemporary samples. The high sensitivity afforded by AMS allows the fate of environmental carcinogens, mutagens, and toxins to be studied on the molecular level at extremely low levels of exposure. Existing AMS systems use large, costly nuclear physics accelerators which are not generally available to biomedical researcher and are not compatible with interface to standard chromatographs used for the purification of biological samples. The research is intended to lead to development of a dedicated, biomedical AMS system based on a new approach which allows the accelerator energy to be lowered by approximately a factor-of-three compared with existing systems. This greatly reduces the size, cost, and complexity of the instrument. The feasibility of this approach was demonstrated in the Phase I experiments which showed that an AMS system using a 1 MV tandem accelerator will allow the unambiguous detection of 14C in labeled contemporary samples. The Phase II research will focus on the construction and testing of the first on-line sample purification and injection interface for biomedical AMS. The interface will make possible the direct introduction of biological samples from a gas chromatograph into an AMS system thereby allowing the use of AMS in conjunction with standard, high resolution chemical separation techniques. The system will provide the critical front-end technology for a dedicated low energy AMS instrument and will also make possible the use of any existing AMS system for on-line analysis of biological samples. This system will be of interest to research and analytical laboratories studying the biological effects of environmental carcinogens and genotoxins. ***