New Spectrofluorimetric Method for Determining Cadaverine Following Derivation with Orthophthalaldehyde: Application in Fish Tissue

A new spectrofluorimetric method was developed in this study for simple determination of cadaverine (CD) (1,5-diaminopentane) in flesh of mackerel fish. This method required homogenization of the flesh, solid phase extraction (SPE) with 0.4M HCl/methanol or water/methanol (25/75 v/v), centrifugation and derivation with orthophthalaldehyde (OPA). Physico-chemical parameters that affected the sensitivity of the fluorescence signal of the cadaverine-dihydrochloride/orthophthalaldehyde complex (CD/OPA), were optimised; these included reaction time, temperature, solvent system, pH and reactants concentrations (OPA/CD). The study was conducted in acetate buffer (pH 3.5 and 7) and showed low limits of detection (LOD), 0.6 and 25.5 ng.mL– 1 respectively. The limits of quantification (LOQ) obtained were 3.5 ngmL–1 (pH 3.5) and 122 ngmL–1 (pH 7). The sensitivity of the results allowed its satisfactory application for quantification of cadaverine in fish.