4,5-DIAMINOPHTHALHYDRAZIDE AS A HIGHLY SENSITIVE AND SELECTIVE CHEMILUMINESCENCE DERIVATIZATION REAGENT FOR ALDEHYDES IN HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

4,5-Diaminophthalhydrazide is shown to be a highly sensitive chemiluminescence derivatization reagent for aldehydes, especially for aromatic aldehydes, in high-performance liquid chromatography (HPLC). The reagent reacts selectively with aldehydes in acidic media to give highly chemiluminescent benzimidazol derivatives which produce chemiluminescence by reaction with hydrogen peroxide and potassium hexacyanoferrate(III). The derivatives in the reaction mixture of four aldehydes are separated by reversed-phase HPLC with isocratic elution, followed by chemiluminescence detection. For a 20-mu l injection volume, the detection limits (S/N=3) for aromatic and aliphatic aldehydes are in the ranges 1 - 150 fmol and 0.05 - 2.8 pmol, respectively.