A non-fluorescent derivative from derivatizing trans, trans-muconic acid with 2-(2-naphthoxy)ethyl-2-(piperidino)ethanesulfonate.

trans, trans-Muconic acid (MA) is a polar metabolite of benzene and used as a biomarker for monitoring human exposure to benzene. Because MA is a trace metabolite, sensitive method is required for its detection. In addition, MA is a highly polar compound with dicarboxyl functions that could incur unfavorable adsorption on silica-based stationary phase usually used for separation. To address these problems, we planned to derivatize MA with a fluorescent reagent 2-(2-naphthoxy)ethyl-2-(piperidino)ethanesulfonate to give a naphthoxy derivative of MA for improving detection sensitivity and chromatographic properties. Surprisingly, the resulting derivative shows no fluorescent activity (lambda(ex): 226 nm; lambda(em): 350 nm). The negative results could be used as an instructive example for discussing on fluorescence quenching.