Abstract
Urinary kynurenine was converted into 2-aminoacetophenone by heating with barium hydroxide and was analyzed in the form of its trifluoroacetyl derivative by gas chromatography. The peak having a retention time equal to that of authentic 2-trifluoroacetylaminoacetophenone was investigated by combined gas chromatography-mass spectrometry. The procedures are shown in the following lines.
Ten ml of saturated barium hydroxide and 1g of barium hy droxide powder were added to 10ml of urine sample, and the mixture was heated in a boiling water bath under ref lux for 20min. After cooling in an ice bath, 1.0ml of chloroform solution containing p-xylene-dichloride as an internal standard was added, and the solution was extracted with twice 5ml of chloroform. The combined chloroform extract was evaporated to dryness under reduced pressure, and a drop of ethylacetate and two drops of trifluoroacetic anhydride were added to the residue, and the reaction solution was injected onto the gas chromatograph.
