LC-APCI-MS/MS Analysis of urinary 8-hydroxy-2’-deoxyguanosine

8-hydroxy-2'-deoxyguanosine (8-HO-dG) is regarded as un important biomarker of oxidative DNA damage, and it may be estimeted by using different techniques in various biological matrices, most notabily DNA and urine., In the case of DNA artifactual oxidation may take place during the isolation of DNA, its hydrolysis and possible derivatization (as for GC-MS) , invalidating the measurement of 8-OH-dG. Therefore, the direct analysis of 8-OH-dG excreted into urine was preferred. Interferences from the urine matrix were excluded by applying LC-APCI-MS/MS in Multiple Reaction Monitoring (MRM) mode. The abundant fragment ion at m/z 168 arising from 8-OH-dG was monitored in urine sample of volunteers supplemented with tomato concentrate for different times. The procedure allowed to detect levels of 8-OH-dG as low as 1 ng/mL urine sample.