Measurement of formaldehyde in a single puff of cigarette smoke using tunable diode laser infrared spectroscopy

A mettled has been developed for measuring formaldehyde in single puffs of mainstream (MS) and per cigarette in sidestream (SS) smoke with the use of tunable diode laser (TDL) infrared spectroscopy, Thirty to fifty percent of the total MS formaldehyde delivery per cigarette is generated in the lighting puff. This phenomenon is unique to formaldehyde compared to most other gaseous smoke components. The effect of the lighting technique, parking density of the tobacco in the cigarette rod, flow rate of air (heating rate) through the cigarette coal (burning zone), and tobacco type on the formaldehyde levels were studied. Calibration was based on measuring the second-derivative spectral response of formaldehyde generated from certified paraformaldehyde permeation tubes. The accuracy of the measured value of this standard was determined to be within +/-0.7% of the certified formaldehyde delivery by performing periodic gravimetric measurements. In addition, the formaldehyde standard was collected in a water trap and analyzed by using a colorimetric analytical technique, providing an agreement of +/-2% with the TDL measurement, The TDL method precision was less than or equal to1% with the use of the permeation standard. The MS formaldehyde deliveries for a Philip Morris monitor and Kentucky Reference 1R4F cigarette were 37 +/- 5 and 27 +/- 5 mug/cigt., respectively. The 1R4F value was in close agreement with results found by using an HPLC method reported in the literature. The MS sampling system can be quickly modified to determine formaldehyde levels in sidestream smoke. The SS formaldehyde delivery for the Philip Morris monitor cigarette was 2.1 +/- 0.1 mg/cigt. (i.e., 0.27 +/- 0.01 mg/min). The range of SS deliveries for reference, experimental, and commercial brands was much less than that observed for the MS smoke deliveries of similar cigarettes.