A method of enriching a solution of an adenovirus comprising applying a mixed solution comprising an adenovirus and at least one undesired type of biomolecule to an anion exchange chromatography resin containing a binding moiety selected from the group consisting of dimethylaminopropyl, dimethylaminobutyl, dimethylaminoisobutyl, and dimethylaminopentyl and eluting the adenovirus from the chromatography resin. Also provided is a method of purifying an adenovirus from adenovirus-infected cells comprising lysing such cells, applying the lysate to a single chromatography resin, eluting the adenovirus from the chromatography resin, and collecting a fraction containing adenovirus that is substantially as pure as triple CsCl density gradient-purified adenovirus. The present method further provides a method of accurately quantifying the number of adenoviral particles in a solution of adenovirus comprising applying to and eluting from an anion exchange chromatography resin a sample solution of adenovirus, comparing the absorbance of the sample solution of adenovirus and the absorbance of a standard solution of adenovirus, and quantifying the number of adenoviral particles in the sample solution.