Poly (N-octyl-4-vinylpyridinium) bromide was used as solid phase for adsorption of As (V) from aqueous solutions. The direct measurement of fluorescence from the solid phase can be used to develop a method for determination of As (V). The fluorescence of the solid phase increases with increasing the concentration of adsorbed As (V). Application of a method for the direct determination of As (V) on the solid phase.