Mass Spectrometric Quantitation of N'-Nitrosonornicotine-1N-oxide in the Urine of Cigarette Smokers and Smokeless Tobacco Users.

ABSTRACT: N'-Nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), which always occur together and are present exclusively in tobacco products, are classified as "carcinogenic to humans" (Group 1) by the International Agency for Research on Cancer. While 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) serves as an excellent biomarker for NNK exposure, the currently available biomarker for NNN exposure is urinary "total NNN" (free NNN plus its N-glucuronide). Quantitation of urinary NNN requires extensive precautions to prevent artifactual formation of NNN resulting from nitrosation of nornicotine during analysis. NNN itself can also be formed endogenously by the same nitrosation reaction, which may sometimes cause an overestimation of exposure to prefo

SUBMITTER: Li Y 

PROVIDER: S-EPMC9608542 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature