SENSITIVE DETECTION OF BIACETYL IN LIQUID-CHROMATOGRAPHY USING TIME-RESOLVED SENSITIZED PHOSPHORESCENCE

A detection method in liquid chromatography for blacetyl [a flavor component] is described. This method, called sensitized room-temperature phosphorescence in liquids (RTPL), is based on triplet-triplet energy transfer from a donor, 1,5-naphthalenedisulfonic acid disodium salt, to blacetyl, acting as acceptor. In this way (despite its low absorptivity) a high number of analyte molecules are transferred to the triplet state. The choice of an optimal donor compound is discussed. By use of a reversed-phase HPLC [high performance liquid chromatography] system, a detection limit of 1 .times. 10-8 M blacetyl in standard solutions can be obtained. The linearity of response is more than 2 orders of magnitude; for standard samples the relative SD is smaller than 3.4% (n = 5). A luminescence detector working in the pulsed source-time resolved mode is used. Optimization of the instrumental parameters leads to an improved signal to noise ratio compared to conventional detectors. The practical applicability of the method is indicated by the measurement of blacetyl in a beer sample.