CONCENTRATION AND FRACTIONATION OF AROMAS ON REVERSE-PHASE ADSORBENTS

A new procedure for concentration and fractionation of volatile aroma chemicals was devised. The dilute aroma-bearing aqueous solution is passed over a reverse-phase packing and concentration of the volatiles is achieved. A solvent gradient is generated and the aroma chemicals are desorbed. Retention of the aromatics is proportional to the number and type of hydrocarbon groups present; thus fractionation occurs. Fractions are obtained which may be subjected to organoleptic analysis, GC, HPLC or GC-MS [gas chromatography, high performance liquid chromatography, gas chromatography-mass spectrometry]. Recoveries are generally > 80%. Experimental details are discussed, and the technique is applied to a homologous series of methyl esters, a mixture of flavor chemicals, a peppermint oil and a carbonated beverage.