DETERMINATION OF DAMINOZIDE AND DIMETHYLHYDRAZINE RESIDUES IN SWISS APPLE JUICE CONCENTRATES USING GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

Apple juice concentrates analyzed for daminozide and 1,1-dimethylhydrazine (UDMH) by a sensitive gas chromatographic mass spectrometric (GC-MS) method showed with the exception of one sample no detectable concentrations of daminozide. The exceptive sample showed traces of daminozide (0.07 ppm) that could have resulted from the illegal use of daminozide by one fruit grower from more than a hundred. The samples were collected from large-scale storage tanks in different regions in Switzerland and represented a cross section of Swiss production. The samples were analyzed for daminozide after alkaline digestion to UDMH and derivatization to pentafluorobenzoyl derivatives. The exceptive apple juice concentrate was further analyzed directly for UDMH by isolation via cation-exchange chromatography and derivatization. No UDMH was found in this analysis. Comparative analysis showed the GC-MS method to be much less susceptible to interfering compounds than electron capture detection. Other hydrazines were comparatively analyzed and GC and MS properties of the pentafluorobenzoyl derivatives reported.