Disclosed herein are apparatus and methods for detecting and quantifying contaminants in aqueous solutions. The vulcanizing press further includes a lockingunlocking device comprising a first movable stop that can move between a rest position and an active position, in which said stop is interposed between the head of the pin and the support plate in order to keep said pin in the bore, the shank of said pin being fixed to the mold. The catalysts exhibit reduced agglomeration of catalyst particles as compared to conventional noble metal catalysts.