We present in this article a stochastic algorithm based mainly on [Monte Carlo Methods and Applications 5(1) (1999) 1; Stochastic particle approximations for Smoluchowski's coagulation equation. Technical Report, Weierstrass-Institut for Applied Analysis and Stochastics, 2000. Preprint No. 585] applied to the integration of the General Dynamics Equation (GDE) for aerosols. This algorithm is validated by comparison with analytical solutions of the coagulation-condensation model and may provide an accurate reference solution in cases for which no analytical solution is available.