Table 1. Urinary biomarkers of exposure and bioanalytical methods.
| Biomarkera | Abbreviation | Chemical Constituent | Method | LLOQ | LOD |
|---|---|---|---|---|---|
| Nicotine equivalents | NicEq | Nicotine | NA | ||
| Unconjugated nicotine | NIC-U | Nicotine | LC-MS/MS | 10 mg mL−1 | 5 ng mL−1 |
| Unconjugated cotinine | COT-U | Nicotine | LC-MS/MS | 7.4 ng mL−1 | 2.5 ng mL−1 |
| Unconjugated trans-3′-hydroxycotinine | OHCOT-U | Nicotine | LC-MS/MS | 12.3 ng mL−1 | 4.1 ng mL−1 |
| Nicotine-glucuronide | NIC-G | Nicotine | LC-MS/MS | 10 ng mL−1 | 3 ng mL−1 |
| Cotinine-glucuronide | COT-G | Nicotine | LC-MS/MS | 25 ng mL−1 | 10 ng mL−1 |
| Trans-3′-hydroxycotinine-glucuronide | OHCOT-G | Nicotine | LC-MS/MS | 21.6 ng mL−1 | 7.2 ng mL−1 |
| Cotinine-N-oxide | CNO | Nicotine | LC-MS/MS | 10 ng mL−1 | 4 ng mL−1 |
| Nicotine-N-oxide | NNO | Nicotine | LC-MS/MS | 10 ng mL−1 | 5 ng mL−1 |
| Norcotinine | NCOT | Nicotine | LC-MS/MS | 10 ng mL−1 | 3 ng mL−1 |
| Nornicotine | NNIC | Nicotine | LC-MS/MS | 10 ng mL−1 | 4 ng mL−1 |
| Total 4-(methylnitrosamino)-1(3-pyridyl)-butanol | NNAL-T | NNK | LC-MS/MS | 5 pg mL−1 | 2 pg mL−1 |
| Unconjugated 4-(methylnitrosamino)- 1(3-pyridyl)-butanol | NNAL-U | NNK | LC-MS/MS | 5 pg mL−1 | 2 pg mL−1 |
| 4-(Methylnitrosamino)-1(3-pyridyl)-butanol glucuronide | NNAL-Gb | NNK | Calculated | NA | NA |
| 3-Hydroxypropylmercapturic acid | 3-HPMA | Acrolein | LC-MS/MS | 20 ng mL−1 | 6.2 ng mL−1 |
| S-phenylmercapturic acid | S-PMA | Benzene | LC-MS/MS | 0.05 ng mL−1 | 0.03 ng mL−1 |
| Monohydroxybutenylmercapturic acid | MHBMA | 1,3-Butadiene | LC-MS/MS | 0.10 ng mL−1 | 0.03 ng mL−1 |
| 3-Hydroxy-1-methylpropyl-mercapturic acid | HMPMA | Crotonaldehyde | LC-MS/MS | 52 ng mL−1 | 17 ng mL−1 |
| total 1-hydroxypyrene | 1-OHP-T | Pyrene | GC-MS/MS | 0.01 ng mL−1 | 0.003 ng mL−1 |
| o-Toluidine | o-T | o-Toluidine | GC-MS | 2.5 ng L−1 | 0.8 ng L−1 |
| 2-Aminonaphthalene | 2-AN | 2-Aminonaphthalene | GC-MS | 1.7 ng L−1 | 0.6 ng L−1 |
| 3-Aminobiphenyl | 3-ABP | 3-Aminobiphenyl | GC-MS | 1.3 ng L−1 | 0.5 ng L−1 |
| 4-Aminobiphenyl | 4-ABP | 4-Aminobiphenyl | GC-MS | 1.5 ng L−1 | 0.5 ng L−1 |
| N-Acetyl-S-(2-carbamoylethyl)cysteine | AAMA | Acrylamide | LC-MS/MS | 4.1 ng mL−1 | 1.2 ng mL−1 |
| N-acetyl-S-(2-hydroxy-2-carbamoylethyl)cysteine | GAMA | Acrylamide | LC-MS/MS | 1.0 ng mL−1 | 0.3 ng mL−1 |
| Creatinine | CRE | Creatinine | Picric acid assay | 13.1 mg dL−1 | NA |
aAnalyzed at Analytisch Biologisches Forschungslabor (ABF, Munich, Germany) except for creatinine, which was analyzed at Celerion (formerly MDS Pharma, Lincoln, NE).
bCalculated as NNAL-T–NNAL-U
LLOQ, lower limit of quantitation; NA, not applicable; LC-MS/MS, liquid chromatography-tandem mass spectrometry; GC-MS, gas chromatography–mass spectrometry.