SIMPLE AND SENSITIVE DETERMINATION OF DIACETYL AND ACETOIN IN BIOLOGICAL SAMPLES AND ALCOHOLIC DRINKS BY GAS-CHROMATOGRAPHY WITH ELECTRON-CAPTURE DETECTION

Acetoin was quantitatively oxidized into diacetyl by Fe3+ in 1 M perchloric acid. The reaction of diacetyl with 4,5-dichloro-1,2-diaminobenzene afforded 6,7-dichloro-2,3-dimethylquinoxaline (DCDMQ), which was extracted by benzene containing aldrin (25 ng/ml) as an internal standard, and determined by gas chromatography with electron-capture detection. The method is very simple and sensitive. The detection limit of DCDMQ (either diacetyl or acetoin) was 10 fmol/mu-l of the benzene extract, and the determination limit of DCDMQ (either diacetyl or acetoin) was 50 fmol/mu-l of the extract. Both acetoin and diacetyl could be determined in 0. 1 ml of normal human urine or blood, and both were found in rat liver, kidney and brain. The method was also applied to the determination of acetoin and diacetyl in alcoholic drinks.