Abstract: A well known technique to determine the decay amplitudes of non-leptonic B meson processes is QCD factorization. One of the main issues faced by this procedure is the analytical determination of power suppressed terms, for instance of annihilation topologies. In this talk we describe the extraction of the annihilation contributions from data. Our method is based on establishing a set of rules which allows us to transform the SU(3)-invariant description of B decay amplitudes into pairs of pseudoscalar particles and the QCD factorization decomposition. Our approach provides not only the size of this contributions from phenomenological considerations but also a formal proof of the maximal number of degrees of freedom in the SU(3)-invariant, the topological and the QCD-factorization representations of B decay amplitudes into Pseudoscalar particles.