Table 4

 Survey of internal industry methods for measurement of free-base nicotine45,49,56,58,62,76–80

MethodDescriptionIndustry commentsIndustry 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 spectroscopyLTC (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 PMBWTC (1965): Good agreement with strength perception, and smoke pH measurementsBWTC: 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 padBWTC: Experiments in 1984
Gas phase nicotine- denuder tubes (PMTC -1991)Use of open-tube denuders to separate vapour phase from PM nicotinePMTC (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 differencesPMTC: 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 mediumRJRTC (1991): Mimics vapour removal with minimal particle deposition characteristic of the human airwayRJRTC: “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 coatingRJRTC (1991): “Incorporates physical properties of upper airway”… “quantitative measures… can be related to human experience”RJRTC: Proposed in 1991; results unknown