Metabolic profile of nicotine excretion in human urine according to the literature
| Investigated substances | Nicotine | Cotinine | trans-3′- hydroxycotinine |
|---|---|---|---|
| Human excretion (%)—free form* | 10 | 13 | 35 |
| Human excretion (%)—conjugated† form* | 3 | 17 | 9 |
| Sum free+conjugated forms (%) | 13 | 30 | 44 |
*Data from Ref. 14; amounts excreted were corrected to nicotine equivalents (nicotine molecular weight/metabolite molecular weight).
†Conjugated form consists of glucuronides.