Survey of internal industry methods for measurement of free-base nicotine45,49,56,58,62,76–80
| Method | Description | Industry comments | Industry use |
|---|---|---|---|
| BWTC, Brown & Williamson Tobacco Company; LTC, Lorillard Tobacco Company; PMTC, Philip Morris Tobacco Company; RJRTC, RJ Reynolds Tobacco Company. | |||
| Shmuk (1953) | Selective solvent extraction, with quantification by chromatography or spectroscopy | LTC (1976): “this should not be a difficult analysis.” | LTC: “Quick check” GC method in place; however, the proposed standard assay “was never acted upon” |
| Extractable nicotine (BWTC -1965) | Chloroform extraction of free base nicotine from aqueous solution of smoke PM | BWTC (1965): Good agreement with strength perception, and smoke pH measurements | BWTC: Standard use of extractable nicotine measurements maintained at least until 1984 |
| BWTC (1974, 1977): Unusually high results/adjustments required for low-tar, low weight cigarettes | |||
| Nuclear magnetic resonance (PMTC -1975) | Measure of changes in the chemical shift of the n-methyl resonance of nicotine. | PMTC (1975): “The results obtained by this method indicate that the condensates are not acidic and the majority of nicotine in condensate exists as the free base” | PMTC: Published research using NMR technology in 1977; further internal use undetermined |
| Headspace nicotine (BWTC -1984) | Headspace GC determined for PM collected via Cambridge pad | BWTC: Experiments in 1984 | |
| Gas phase nicotine- denuder tubes (PMTC -1991) | Use of open-tube denuders to separate vapour phase from PM nicotine | PMTC (1991): “technique seems to be sufficiently definitive for any significant changes in relative deliveries of nicotine in the vapor phase”; not effective for defining small differences | PMTC: Experiments throughout 1991 |
| (RJRTC -1990) | RJRTC (1990): “low rates of nicotine removal relative to expected vapor deposition rates” | RJRTC: used in 1990, replaced by bubbler adsorption 1991 | |
| RJRTC (1991): “uncertainty that the inner walls of the syringe remained sufficiently wetted throughout the smoke aging to act as perfect sinks for nicotine vapor.” | |||
| Bubbler adsorption—volatile nicotine (RJRTC -1991) | Smoke passed through bubbler containing water as adsorption medium | RJRTC (1991): Mimics vapour removal with minimal particle deposition characteristic of the human airway | RJRTC: “converted to standard method” in 1991, with major improvement in results; technique “being applied to many studies.” |
| Spinning denuder-volatile nicotine (RJRTC -1991) | Denuder-based method, using spinning to ensure uniform solvent coating | RJRTC (1991): “Incorporates physical properties of upper airway”… “quantitative measures… can be related to human experience” | RJRTC: Proposed in 1991; results unknown |