A carbon column-based liquid chromatography electrochemical approach to routine 8-hydroxy-2 '-deoxyguanosine measurements in urine and other biologicmatrices: A one-year evaluation of methods

8-Hydroxy-2'-deoxyguanosine (80H2'dG) is a principal stable marker of hydro xyl radical damage to DNA. It has been related to a wide variety of disorde rs and environmental insults, and has been proposed as a useful systematic marker of oxidative stress. Analytic procedures for 80H2'dG in DNA digests are well established; however, routine measurement of free 8OH2'dG in other body fluids such as urine or plasma has been problematic. This has hindere d its evaluation as a general clinical, therapeutic monitoring, or environm ental assessment tool. Therefore, we developed a liquid chromatography elec trochemical column-switching system based on the use of the unique purine s electivity of porous carbon columns that allows routine accurate measuremen t of 80H2'dG in a variety of biologic matrices. This paper describes the ra tionale of the system design and the protocols developed for 80H2'dG in uri ne, plasma, cerebrospinal fluid, tissue, DNA, saliva, sweat, kidney dialysi s fluid, foods, feces, culture matrix, and microdialysates. Concentrations in both human and animal body fluids and tissues are reported. The system p erformance is discussed in the context of a 1-year evaluation of the method s applied to approximately 3600 samples, using internal quality control and external blind testing to determine long-term accuracy. The methods are re liable and accurate, and therefore should prove useful in assessing the rol e and utility of oxidative DNA damage in aging and human illness. (C) 1999 Elsevier Science Inc.