CORE--ANALYTIC CHEMICAL SERVICES

这一核心为定量和定性分析提供了工具支持和技术专长。这包括自动定量硝酸盐和硝酸盐/亚硝酸盐；测量一氧化氮、硝酸盐或亚硝胺中的~5N；烷基化嘌呤的定量；甲基、二甲基和三甲胺；胸腺嘧啶、黄嘌呤、鸟嘌呤、8-氧鸟嘌呤和5-羟甲基尿嘧啶等；挥发性N-亚硝基化合物的定量和表征；游离一氧化氮和一氧化二氮；谷胱甘肽、谷胱甘肽和S-亚硝基谷胱甘肽；修饰或未经修饰的蛋白质、多肽或寡核苷酸的分子量测定；合成模型化合物和实验反应产品的表征；修饰和未修饰的多肽和寡聚核苷酸的表征。主要设备包括三台质谱仪，即惠普5989A GC-MS(具有电子电离、正离子化学电离和负离子化学电离)、惠普5989B电喷雾。质谱仪和芬兰TSQ7000串联质谱仪，具有电喷雾、常压化学电离和纳米电喷雾功能。HP 5989B可用于常规的电喷雾MS，其他设备包括液相色谱仪(二极管阵列检测、荧光、电化学和激光诱导荧光(LIF))、紫外可见光谱仪、一氧化氮输送系统。核心的具体目标源自计划项目的目标，可能包括为8-氧代-2‘-脱氧鸟苷与过氧亚硝酸根的反应等系统开发分析方法，或开发软件来解释修饰寡核苷酸的碰撞诱导分解质谱图。除了在项目期间提出的目标外，核心还有增强其整体能力的目标，例如，用激光诱导荧光检测对毛细管LC进行评估，将其作为量化与一氧化氮和过氧亚硝酸盐相关的DNA和蛋白质损伤的超灵敏方法，以及用于表征未知因素的纳米电喷雾和微电喷雾。

This Core provides instrumental support and technical expertise for quantitative and qualitative analyses. This includes, e.g., automated quantitation of nitrate and nitrate/nitrite; measurement of '5N in nitric oxide, nitrate, or nitrosamines; quantitation of alkylated purines; methyl-, dimethyl-, and trimethylamine; thymine, xanthine, guanine, 8-oxoguanine, and 5-hydroxymethyluracil, etc.; quantitation and characterization of volatile N-nitroso compounds; free nitric oxide and nitrous oxide; glutathione (GSH), GSSG, and S-nitrosoglutathione; molecular weight determination for modified or unmodified proteins, peptides, or oligonucleotides; characterization of synthetic model compounds and experimental reaction products; characterization of modified and unmodified peptides and oligonucleotides. Major equipment includes three mass spectrometers, i.e., a Hewlett Packard 5989A GC-MS (with electron ionization, positive chemical ionization, and negative ion chemical ionization), a Hewlett Packard 5989B electrospray. mass spectrometer, and a Finnigan TSQ7000 tandem mass spectrometer with electrospray, atmospheric pressure chemical ionization, and nanoelectrospray. The HP 5989B has open-access for routine electrospray MS. Other equipment includes liquid chromatographs (detection by diode- array, fluorescence, electrochemistry, and laser-induced fluorescence (LIF)), uv-visible spectrophotometers, a nitric oxide delivery system. The specific objectives for the Core derive from those of the Program Projects, and may include development of analytical methods for systems such as the reaction of 8-oxo-2'-deoxyguanosine with peroxynitrite or development of software to interpret the collisionally-induced decomposition mass spectra of modified oligonucleotides. In addition to objectives that arise during a project, the Core has objectives to enhance its overall capabilities, e.g., assessment of capillary LC with LIF detection as an ultrasensitive method for quantitating nitric oxide-related and peroxynitrite-related DNA and protein damage, and nanoelectrospray and microelectrospray for the characterization of unknowns.