Sensitizers for the room temperature phosphorescence of biacetyl in fats

Abstract

The determination of the biacetyl concentration in fats can be achieved by measuring the phosphorescence emission of biacetyl at room temperature. The biacetyl phosphorescence can be sensitized using suitable donors by means of a triplet–triplet energy transfer. The spectroscopic characteristics of four newly synthesized coumarin derivatives, which are soluble in non-polar solvents, have been studied. In order to determine whether a triplet–triplet energy transfer is possible, the energy of the lowest triplet state of these derivatives was determined by using phosphorescence spectroscopy. Their ability to sensitize the biacetyl phosphorescence has been investigated and the 6,7-dihydro-3-ethoxycarbonylpsoralen appeared to be the best sensitizer. In this instance, a biacetyl concentration as low as 0.05 ppb (µg kg^–1) can be determined in butter samples.