A method for transferring a quantity of analytes comprising at least stages of: predisposing a substantially homogeneous mixture of a predetermined initial quantity of at least an analyte and a liquid, obtaining a known concentration value or known amount of the analyte in the mixture introducing into the mixture at least a collecting portion (3) of a sampling device (1) having a support body (2), the collecting portion (3) comprising a plurality of fibers (6) attached to and arranged on a first portion (2a) of the support body (2) by means of flocking, in order to define a flocked collecting portion (3) or a flocked tampon, such as to collect a part of the mixture on the collecting portion (3) and extracting the collecting portion (3) of the sampling device (1) of the mixture, retaining on the sampling portion (3) a predetermined known quantity of the mixture to be transferred.
