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