Abstract: A polymer for liquid chromatography or solid phase extraction is provided. The polymer is prepared by polymerizing styrene and divinylbenzene to form a styrene-divinylbenzene copolymer; soaking the styrene-divinylbenzene copolymer in a swelling agent to form nano-scale micropores; and soaking the microporous styrene-divinylbenzene copolymer in methanol. When packed in a chromatographic column, the polymer can be used to produce produce natural health or medicinal products from Cannabis species, for example, industrial hemp.