Analytical methods for measurement of biomarkers of secondhand smoke exposure (SHSe)
| Method | Sensitivity | Specificity | Cost | Comments |
| Cotinine | ||||
| Radioimmunoassay (RIA)13 14 | 0.10–2.00 ng/ml | Variable (poorest in urine) | Low | Quick and relatively low cost analysis of large number of samples |
| ELISA14 15 | 0.10–0.20 ng/ml | Good | Low | Quick and relatively low cost analysis of large number of samples |
| Gas chromatography-nitrogen-phosphorous detection (GC-NPD)16 | 0.10–0.20 ng/ml | Good | Moderate | Lacks sensitivity for very low level of SHSe |
| Gas chromatography-mass spectrometry (GC-MS)18 | 0.10–0.20 ng/ml | Excellent | High | |
| Liquid chromatography-atmospheric pressure chemical ionization tandem mass spectrometry (LC-APCI MS/MS)21 | <0.05 ng/ml | Excellent | Extremely high | Current state-of-the-art method for urine cotinine. It can perform 100 samples/day |
| High performance liquid chromatography (HPLC)22 23 | 0.13–1.00 ng/ml | Good | Moderate | |
| Nicotine | ||||
| GC-MS23 | 0.02–0.25 ng/ml | Excellent | Moderate-high | It has been used for nicotine determination in hair and toenails |
| HPLC19 23 | 0.10–0.32 ng/ml | Good | Low | It has been used for nicotine determination in hair and with electrochemical detection for toenails |
| NNAL (4-[methylnitrosamino]-1-[3-pyridyl]-1-butanol) | ||||
| Liquid chromatography-tandem mass spectrometry (LC-MS/MS)20 | 0.25 pg/ml | Excellent | Extremely high | NNAL assay of choice. |
| Gas chromatography-thermal energy analysis (GC-TEA)17 | 0.15 pmol/ml | Excellent | Moderate | Difficult implementation |
Modified from Benowitz 1996.4