An analytical method, specifically developed and used to determine the presence of geosmin in wine, was evaluated for the simultaneous determination of geosmin, responsible for an earthy off-flavour, 4-ethylphenol and 4-ethylguaiacol, responsible for phenolic off-flavour and of selected volatile wine aroma compounds. The method consists of a liquid-liquid extraction with n-pentane followed by GC-MS/SIM analysis. The linearity of the response was very good (r2>0.9956) in the usual concentration ranges of the volatiles in wines. The precision was also very good (%RSD less than or near 10%) and the accuracy of the method, was satisfactory. LOD and LOQ were below 1 or a few mg/L for most compounds. The method was then applied to evaluate the efficacy of a treatment with deodorant activated charcoal to decrease the amount of geosmin, 4-ethylphenol, 4-ethylguaiacol and its effect on the concentration of the volatile aroma compounds, both in red and white wines.