Cyclodextrin enhanced fluorimetric determination of malonaldehyde by the thiobarbituric acid method

The enhancement effects of alpha-, beta-, gamma;- and hydroxypropyl-beta-cyclodextrins on the fluorescence of a 2:1 thiobarbituric acid/malonaldehyde adduct in acid aqueous solutions have been studied. The best characteristics as a fluorescence enhancement agent showed hydroxypropyl-beta-cyclodextrin which bound the adduct sufficiently tightly (K = 180 1 mol(-1)) mol(-1)) and caused a five-fold increase in its fluorescence. A kinetic-fluorimetric method of determination of malonaldehyde in the range 0.1-10 microM at room temperature with hydroxypropyl-beta-cyclodextrin as the enhancement agent is proposed and applied for the analysis of raw and cooked meat samples.