Fast quantification of the urinary marker of oxidative stress 8-hydroxy-2'-deoxyguanosine using solid-phase extraction and high-performance liquid chromatography with triple-stage quadrupole mass detection.
Exogenous and endogenous oxidants constantly cause oxidative damage to DNA. Since the reactive oxidants itself are not suitable for analysis, oxidized bases like 8-hydroxy-2'-deoxyguanosine (8OHdG) are used as biomarkers for oxidative stress, either in cellular DNA or as elimination product in urine. A simple, fast and robust analytical procedure is described for urinary 8OHdG as an indicator of oxidative damage in humans. The adduct was purified from human urine by applying a single solid-phase extraction step on LiChrolut EN. After evaporation of the eluate, the residue was resolved and an aliquote was injected into a HPLC system with a triple quadrupole mass spectrometer. The limit of detection was 0.2 ng ml(-1) (7 fmol absolute) when using one product ion as quantifier and two further product ions as qualifier. The coefficient of variation was 10.1% (n=5 at 2.8 ng ml(-1) urine). The sample throughput was about 50 samples a day. Thus, this method is more sensitive and much faster than the common method using HPLC with electrochemical detection. The results of a study with nine volunteers investigated at six time-points each over 5 days are presented. The mean excretion of 8OHdG was 2.1 ng mg(-1) creatinine (range 0.17-5.9 ng mg(-1) creatinine; 4 of 53 samples were below the LOD). A relatively large intra- (relative SD 66%) and inter-individual (relative SD 71%) variation in urinary 8OHdG excretion rates was found.
Renner
T
T
ABF, Analytisch-biologisches Forschungslabor, Munich, Germany.
Fechner
T
T
Scherer
G
G
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000328:Adult; D015415:Biomarkers / Q000652:urine*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000652:urine; D005260:Female; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D018384:Oxidative Stress; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D015415:Biomarkers; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine