In this paper, a modification of the Health Canada method for volatile compounds in mainstream smoke in one analytical run, is described. The goal behind developing this method was to extend the number of target compounds of potential health risk that could be analyzed from one sample. Existing methods for the determination of ethylene oxide in mainstream smoke either employ Tedlar→ bags for collection of the volatiles, therefore limiting the compounds which can be collected, or chemical absorbants which are specific to ethylene oxide alone. Compared to methods based on the collection of gaseous samples, this method is easier to calibrate, more amenable to automation, and has the potential to be extended to less volatile compounds. In this new method, mainstream smoke is passed through a 92 mm pad followed by dry ice cooled impingers containing methanol. Volatile compounds are determined by a combination of ion-trap and selective ion monitoring GC-MS on both a pad extract and the impinger solution. Typical analytical run times were 25 minutes. For control cigarettes (Kentucky Reference 3R4F) smoked under ISO (35/60/2) conditions, the concentration of ethylene oxide and propylene oxide determined (n=18) using this method was 20 µg/cig. and 460 ng/cig. respectively, and for intense smoking conditions (55/30/2, vents blocked), 53.4 µg/cig. and 1162 ng/cig. respectively. These results are comparable to those obtained using the Tedlar→ bag method for other control cigarettes. Ethylene oxide can be determined with a limit of detection (LOD) of 0.4 µg/cig., and propylene oxide 15 ng/cig. Relative standard deviations for measurements of the epoxides under both ISO and intense conditions were between 10 and 15%. The other analytes were determined within 95-108% of the expected values, with relative standard deviations less than 10% and LOD's between 0.1 and 2.5 µg/cig.