Improved determination of malonaldehyde by high-performance liquid chromatography with UV detection as 2,3-diaminonaphthalene derivative.

•Malonaldehyde (MA) is a marker used to follow lipid oxidation phenomena in food.•MA reacted with 2,3-diaminonaphthalene giving a product suitable to HPLC-UV.•The UV response was better than that obtained by MA with 2,4-dinitrophenylhydrazine.•The method were optimized with respect to the longer previously reported one.•The method was applied to estimate free MA in commercial canned mackerel fillets.