Nitrosamines are chemical compounds that are present in tobacco and tobacco smoke. When tobacco burns during smoking, the tobacco specific nitrosamines can transfer to smoke as well as decompose thermally, and additional amounts of the nitrosamines can be formed pyrosynthetically. The purpose of our work is to setup a reliable method for the quantification of tobacco specific nitrosamines in mainstream smoke by using combined gas chromatography-thermal energy analysis. One of the main objectives is to reduce the quantity of solvents used for extraction and cleanup without compromising sensibility and reproducibility. Mainstream smoke is collected on Cambridge filter pads soaked in a methanol solution of ascorbic acid. Cigarettes are smoked under ISO conditions. The TSNAs are extracted from the filter pads with dichloromethane. The extract is then passed through a chromatography column packed with anhydrous sodium sulphate, silica and alumina. The column is first eluted with dichloromethane and successively with dichloromethane/acetone. The latter fraction, in which the TSNAs elute, is collected and concentrated. Finally, after transferring to GC vials, the samples are analyzed by capillary-column gas chromatography and thermal energy analysis. Quantitative determination is carried out by the internal standard technique (N-nitrosoguvacoline as the internal standard).This method was used for the quantitative determination of the following TSNAs: N-nitrosonornicotine (NNN), 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK), N-nitrosoanatabine (NAT) and N-nitrosoanabasine (NAB). Validation tests were carried out to assess recoveries and repeatability of the method for the four target compounds, at various levels of concentrations. Then limits of detection and quantification of the method were determined and reported.