Methods, compositions and kits are disclosed. Enzyme conjugates of Formula I are employed in assays for the determination of an methylenedioxyamphetamine, a methylene-dioxyethamphetamine, and/or a methylenedioxymethamphetamine. Immunogenic conjugates of Formula I are employed to prepare antibodies for an methylenedioxyamphetamine, a methylenedioxyethamphetamine, and/or for a methylene-dioxymethamphetamine for use in assays for the determination of an methylenedioxyamphetamine, a methylenedioxyethamphetamine, and/or a methylene-dioxymethamphetamine. The enzyme conjugates may also be employed to screen antibodies for use in such methods.