Analysis of methylated and oxidized purines in urine by capillary gas chromatography-mass spectrometry.
Methylated purine bases from urine can be quantitated by capillary gas chromatography-mass spectrometry with selected ion monitoring. The method is based on a separation of the purines in urine using XAD-2 column chromatography and bonded-phase extraction methods. The extracted samples are derivatized with N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide and analyzed by capillary gas chromatography-mass spectrometry. The tert-butyldimethylsilyl derivatives of the purines showed excellent GC and GC/MS properties suitable for low-level detection in extracts of human urine as well as in urine extracts from animals treated with the methylating carcinogen N-nitrosodimethylamine. The oxidized purine bases 7-methyl-8-hydroxyguanine, 8-hydroxyadenine, and 8-hydroxyguanine were also detected in urine. To our knowledge, the latter two modified bases have not been previously reported in normal urine.
Stillwell
W G
WG
Division of Toxicology, Massachusetts Institute of Technology, Cambridge 02139.
Xu
H X
HX
Adkins
J A
JA
Wishnok
J S
JS
Tannenbaum
S R
SR
D000225:Adenine / Q000031:analogs & derivatives / Q000652:urine; D000818:Animals; D004128:Dimethylnitrosamine / Q000378:metabolism; D005289:Ferrets; D008401:Gas Chromatography-Mass Spectrometry; D006147:Guanine / Q000031:analogs & derivatives / Q000652:urine; D006801:Humans; D008745:Methylation; D010084:Oxidation-Reduction; D011687:Purines / Q000652:urine*; D051381:Rats; D011916:Rats, Inbred F344
D011687:Purines; C002992:8-hydroxyadenine; C022595:3-ethyladenine; C025946:3-methyladenine; C024829:8-hydroxyguanine; D006147:Guanine; C008450:7-methylguanine; D000225:Adenine; D004128:Dimethylnitrosamine