N-aryl-1,8-naphthalimides as highly sensitive fluorescent labeling reagents for carnitine

4-(2-Aminoethylamino)-N-(4-methoxyphenyl)-1,8-naphthalimide can be used as a fluorescent labeling reagent for carnitine. The excitation and emission m axima of this reagent were observed at 436 and 524 nm in acetonitrile, resp ectively and the reagent reacted smoothly with carnitine to afford the labe led product under mild conditions. The detection limit of carnitine by usin g this reagent was ca. 30 fmol. (C) 1999 Elsevier Science Ltd. All rights r eserved.