title: Gas chromatography--mass spectrometry studies of tetramethyl uric acids.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D002849:Chromatography, Gas; D003978:Diazomethane; D013058:Mass Spectrometry; D008697:Methane; D008722:Methods; D000644:Quaternary Ammonium Compounds; D013237:Stereoisomerism; D014527:Uric Acid / Q000138:chemical synthesis
chemical_list: D000644:Quaternary Ammonium Compounds; D014527:Uric Acid; D003978:Diazomethane; D008697:Methane