The fate of tobacco ingredients during combustion is of major interest and has been discussed in many publications and CORESTA papers. Pyrolysis experiments have been used to identify possible breakdown products and to estimate their potential contribution to Hoffmann Analytes yield. However, reliable predictions are limited since combustion of ingredients applied onto tobacco cannot be simulated by pyrolysis in a straightforward manner. Tracer experiments with radioactive (¹⁴C) or stable ¹³C labelled compounds have been described as an alternative technique to track volatile and non-volatile ingredients and their combustion products in mainstream and sidestream tobacco smoke. For this study, ¹³C labelled glycerol, propylene glycol, geranyl acetate, and tetramethyl pyrazine were applied on tobacco. The test cigarettes were smoked and smoke collected using the sidestream fishtail chimney device. For the examination of fate and behaviour of these ingredients, ¹³C concentrations in CO, CO₂ and volatile hydrocarbons were determined for mainstream and sidestream smoke, the smoked cigarette butt and ash. The ¹²C/¹³C ratio for the different smoking traps was determined using isotope mass spectrometry and the contribution of tracer labelled ingredient to the natural abundance was estimated. The newly developed experimental set-up for the simultaneous determination of CO and CO₂ and for oxidation of volatile hydrocarbons is described. It is confirmed that ¹³C labelled humectants and semi-volatile ingredients significantly contribute to the ¹³C concentration in CO and CO₂. Experimental recovery rates for ¹³C ranged from 92 to 103%.