Objective To provide researchers an extensive characterization of the SPECTRUM variable nicotine research cigarettes. Methods Data on cigarette physical properties, nicotine content, harmful and potentially harmful constituents in the tobacco filler was compiled. Results Data on physical properties, concentrations of menthol, nicotine and minor alkaloids, tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons, ammonia, and toxic metals in the filler tobacco for all available varieties of Spectrum research cigarettes are provided. The similarity in the chemistry and physical properties of SPECTRUM cigarettes to commercial cigarettes renders them acceptable for use in behavioral studies. Baseline information on harmful and potentially harmful constituents in research tobacco products, particularly constituent levels such as minor alkaloids that fall outside typical ranges reported for commercial, provide researchers with the opportunity to monitor smoking behavior and to identify biomarkers that will inform efforts to understand the role of nicotine in creating and sustaining addiction. Conclusions Well characterized research cigarettes suitable for human consumption are an important tool in clinical studies for investigating the physiological impacts of cigarettes delivering various levels of nicotine, the impact of reduced nicotine cigarettes on nicotine addiction, and the relationship between nicotine dose and smoking behavior.

Ammonia and other alkaline substances have been postulated to be important in cigarette design. The most significant potential contribution of ammonia is a possible interaction with the native, protonated nicotine in the smoke. Ammonia is more alkaline than nicotine and could facilitate a shift in the acid/base equilibrium where a fraction of the total nicotine converts to the more lipophilic, non-protonated form. This non-protonated, or free-base, form of nicotine absorbs more efficiently across membranes, resulting in more rapid delivery to the smoker’s bloodstream. Ammonia and other potential ammonia sources, such as additives like diammonium phosphate, could influence the acid–base dynamics in cigarette smoke and ultimately the rate of nicotine delivery. To examine and characterize the ammonia content in modern cigarettes, we developed a fast, simple and reliable ion chromatography based method to measure extractable ammonia levels in cigarette filler. This approach has minimal sample preparation and short run times to achieve high sample throughput. We quantified ammonia levels in tobacco filler from 34 non-mentholated cigarette brands from 3 manufacturers to examine the ranges found across a convenience sampling of popular, commercially available domestic brands and present figures of analytical merit here. Ammonia levels ranged from approximately 0.9 to 2.4 mg per gram of cigarette filler between brands and statistically significance differences were observed between brands and manufacturers. Our findings suggest that ammonia levels vary by brand and manufacturer; thus in domestic cigarettes ammonia could be considered a significant design feature because of the potential influence on smoke chemistry.

Mixed WO 3 -CuWO 4 films have been prepared from aqueous solution of copper sulfate and polytungsten gel with molar ratio Cu/W from 0 to 100 %. These solutions were sprayed onto alumina substrates at 220 ºC. The obtained films were amorphous, and crystallized after an annealing at 300 ºC in air for 3 h. The annealed films were composed by a mixture of CuWO 4 and WO 3 phases. The film obtained from a solution with an equimolar ratio of Cu/W was a pure CuWO 4 . The pure WO 3 films obtained have a high surface "irregularities" (eventually the porosity). Those surface "irregularities" in the films were maintained or eventually increased as Cu/W molar ratio augments in the starting solution up to 10%. The gas sensitivities to butanol and ethanol vapors are also enhanced when the CuWO 4 phase increases in the film up to 7% -10%; further increments to this proportion the detection sensitivity decreases, so compromises are around 7% -10%. The gas sensitivity of pure CuWO 4 was lower than pure WO 3 .