A fluorometric determination of sodium glyoxylate (II), using phenylephrine HCl (I) has been established and the method was applied to the determination of allantoin and aluminium chlorohydroxy allantoinate in pharmaceutical preparations. II was condensed with I into a cyclic substance (V) which was oxidized by K3Fe(CN)6 to a fluorescent substance (VI). Chemical structures of V and VI were found to be 4, 6-dihydroxy-2-methyl-1, 2, 3, 4-tetrahydroisoquinoline-1-carboxylic acid and 6-hydroxy-2-methyliso-quinolinium chloride, respectively. The analytical procedure was as follows : To 1 ml of II solution (5 μg/ml), 1 ml each of 0.2 N NaOH and 0.1% solution of I were added and the mixture was heated for 75 min at 80°. To this mixture, 1 ml each of 2.5N NaOH and 0.06% K3Fe(CN)6 were added and the mixture was further heated for 5 min at 80°. When cooled, it was diluted to 10 ml with methanol. The fluorescence intensity of the solution was measured at 450 nm under excitation at 370 nm.
