Jiye A, Huang Qing, Wang Guangji, Zha Weibin, Yan Bei, Ren Hongcan, Gu Shenghua, Zhang Ying, Zhang Qi, Shao Feng, Sheng Longsheng, Sun Jianguo
Center of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, 24 Tongjia Xiang, Nanjing 210009, China.
Anal Biochem. 2008 Aug 1;379(1):20-6. doi: 10.1016/j.ab.2008.04.025. Epub 2008 Apr 23.
Sediment in urine may contain low-molecular-weight compounds that should be included in the analysis. To date, no systematic investigation has addressed this issue. We investigated three primary factors that influence the extraction efficiency of metabolites during preparation of urine samples for metabolomic research: centrifugation, pH, and extraction solvents. Obtained with the use of gas chromatography/time-of-flight mass spectrometry (GC/TOFMS) technique and principal component analysis (PCA), our results indicate that (1) conventional centrifugation causes an apparent loss of some metabolites, indicating that urine samples for metabolomic research should not be centrifuged before procedures are undertaken to recover the metabolites; (2) pH adjustment has a large impact on the recovery of metabolites and is therefore not encouraged; (3) with design of experiment analysis, methanol and water yield the optimal extraction efficiency. Differences between rat and human urine were observed and are discussed. Ninety-nine metabolites identified in rat and human urine are presented. An efficient protocol is proposed for the pretreatment of urine samples.
尿液中的沉积物可能含有应纳入分析的低分子量化合物。迄今为止，尚无系统研究探讨过这一问题。我们研究了代谢组学研究尿液样本制备过程中影响代谢物提取效率的三个主要因素：离心、pH值和提取溶剂。通过气相色谱/飞行时间质谱（GC/TOFMS）技术和主成分分析（PCA）获得的结果表明：（1）传统离心会导致一些代谢物明显损失，这表明代谢组学研究的尿液样本在进行回收代谢物的操作之前不应进行离心；（2）pH值调节对代谢物的回收率有很大影响，因此不建议进行；（3）通过实验设计分析，甲醇和水的提取效率最佳。观察并讨论了大鼠和人类尿液之间的差异。列出了在大鼠和人类尿液中鉴定出的99种代谢物。提出了一种有效的尿液样本预处理方案。
