Ammonia is listed as one of the Harmful and Potentially Harmful Constituents in tobacco products and tobacco smoke under Section 904(a)(3) of the Federal Food, Drug, and Cosmetic Act. Lancaster Laboratories, Inc has developed an analytical method that can effectively quantitate ammonia in tobacco mainstream smoke. Our modified and improved method is specific, sensitive, simple and robust. The new developed and validated method is an improvement over the historical method as it is run on the new Dionex ICS-2100 ion chromatograph which is equipped with an eluent generator and which utilizes a lower flow rate which in turn saves the amount of chemical waste generated. Also the new method uses a new Cerulean SM450 smoke machine equipped with a Hoffman capture system. Sample preparation is now simple and consistent where as previously the volume and presence of a smoke pad varied by smoke regime. An Ionpac CS12 column is now used to provide better separation of ammonia from interference. Mainstream cigarette smoke is collected onto a Cambridge filter pad and only one impinger containing 40 mLs of 0.006 M HCl is used for effectively trapping ammonia. The average recoveries obtained from the validation studies for 3R4F cigarettes were within ±15% for both ISO and the Health Canada smoke regimes. The established Limits of Quantitation and Limits of Detection are 0.055 μg/mL and 0.016 μg/mL, respectively. The results obtained by running the above method for IR5F, 2R4F and 3R4F cigarettes were within the range of results from the CORESTA Special Analytes Task Force.