Abstract
A procedure is described for the improved identification of compounds in rums. It includes the preparation of rum concentrates using a Kuderna concentrator (KC), and the profiles of the resultant products using a gas chromatographic (GC) system, where the separation with a packed column is compared with that of a capillary column. The packed column was connected in the chromatograph to the flame ionization detector (FID) whereas the capillary column was interfaced, in the same chromatograph, with the mass spectrometry (MS) probe. These techniques assessed simultaneously, provided alternative methods for compound profiles, one using the capillary column only for identification purpose with the GC-MS, and the other with a high performance gas chromatograpy-flame ionization detector (HPGC-FID) with a column. The HPGC-FID offered the best combination for the direct quantitative identification of compounds in rum concentrates. As expected, the number of compounds separated by the two procedures was the same, although some signals in the chromatogram of the packed column were too broad and unresolved. This is the case when highly polar compounds are separated in a packed column with an unmodified liquid phase such as Carbowax 20M. Twenty-two compounds were identified in one rum concentrate, 16 with a probability of 70% or higher of being correctly identified. The present procedure resulted in about a 250 to 500- fold increase in the concentration of compounds, as compared with the concentration of compounds in the original rum sample. The vast majority of these compounds were found at a concentration of 20 ppb or less.