Increased levels of nucleosides modified by oxidation in human cerebrospinal fluid (CSF) have several times been reported in Alzheimer patients and patients suffering from Parkinson’s disease. The focus has especially been on nucleosides containing the 8-hydroxylation of guanine. Only few reports on quantification of the ribonucleoside 8-oxo-7,8-dihydro-guanosine (8oxoGuo) in CSF have been published, whereas more have been published on the quantification of the deoxy-ribonucleoside 8-oxo-7,8-dihydro-2′-deoxyguanosine (8oxodGuo). The reports on the quantification of 8oxodGuo concentrations in CSF report absolute concentrations varying by a factor >10⁵ in healthy humans. This could indicate that there is a serious specificity problem in some of the methods. In this paper an isotope-dilution UPLC–MS/MS method with high specificity and sensitivity for the quantification of 8oxoGuo and 8oxodGuo in CSF is presented. LLOQ for the two analytes is determined to 4pM and 2pM, respectively. The calibration curves has been tested to be linear in the range from 4 to 3,000pM for 8oxoGuo and between 2 and 3,000pM for 8oxodGuo. Using a weighting factor of 1/x the correlation coefficient “r” for both analytes is >0.999.

在人脑脊髓液（CSF）中被氧化修饰的核苷水平增加的报道在阿尔茨海默氏病患者和帕金森氏病患者中已有数次报道。焦点尤其集中在含有鸟嘌呤的8-羟基化的核苷上。关于脑脊液中核糖核苷8-oxo-7,8-二氢-鸟苷（8oxoGuo）定量的报道很少，而有关脱氧核糖核苷8-oxo-7,8-dihydro的定量报道更多。 -2′-脱氧鸟苷（8oxodGuo）。关于脑脊液中8oxodGuo浓度定量的报告，绝对浓度相差> 10 ⁵在健康的人类中。这可能表明某些方法存在严重的特异性问题。本文提出了一种同位素稀释UPLC-MS / MS方法，该方法具有高特异性和灵敏度，可定量测定脑脊液中的8oxoGuo和8oxodGuo。两种分析物的LLOQ分别确定为4pM和2pM。已对8oxoGuo的4至3,000pM范围和8oxodGuo的2至3,000pM范围内的校准曲线进行了测试。使用1 / x的加权因子，两种分析物的相关系数“ r”均大于0.999。