CORE--ANALYTIC CHEMICAL SERVICES

该核心为定量和定性分析提供工具支持和技术专长。这包括，例如，硝酸盐和硝酸盐/亚硝酸盐的自动定量；一氧化氮、硝酸盐或亚硝胺中'5N的测定；烷基化嘌呤的定量；甲基胺、二甲基胺和三甲胺；胸腺嘧啶、黄嘌呤、鸟嘌呤、8-氧鸟嘌呤、5-羟甲基尿嘧啶等；挥发性n -亚硝基化合物的定量和表征；游离一氧化氮和氧化亚氮；谷胱甘肽（GSH）、谷胱甘肽、s -亚硝基谷胱甘肽；修饰或未修饰的蛋白质、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物的表征；修饰和未修饰肽和寡核苷酸的特性。主要设备包括三台质谱仪，即一台惠普5989A气相色谱-质谱仪（带电子电离、正离子化学电离和负离子化学电离），一台惠普5989B电喷雾。质谱仪，以及一台带有电喷雾、常压化学电离和纳米电喷雾的Finnigan TSQ7000串联质谱仪。其他设备包括液相色谱仪（检测二极管阵列，荧光，电化学，激光诱导荧光（LIF）），紫外可见分光光度计，一氧化氮输送系统。核心的具体目标来自于计划项目，可能包括开发系统的分析方法，如8-氧-2'-脱氧鸟苷与过氧亚硝酸盐的反应，或开发软件来解释修饰寡核苷酸的碰撞诱导分解质谱。除了项目中出现的目标外，核心还有提高其整体能力的目标，例如，评估毛细管LC与LIF检测作为定量一氧化氮相关和过氧亚硝酸盐相关DNA和蛋白质损伤的超灵敏方法，以及纳米电喷雾和微电喷雾用于未知特性的表征。

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.