SEPARATION OF STIGMASTA-3,5-DIENE SQUALENE ISOMERS, AND WAX ESTERS FROM OLIVE OILS BY SINGLE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY RUN

To ascertain the authenticity of olive oils, the European Community Re gulation requires the stigmasta-3,5-diene and wax ester contents to be determined. The official methods are time-consuming and not suitable for many daily analyses, as quality-control laboratories need. A metho d is presented here that allows single high-performance liquid chromat ography separation of stigmasta-3,5-diene and wax esters, as well as o f the squalene isomers, which give further information on the oil's au thenticity. For stigmasta-3,5-diene, the comparison with results obtai ned with the official method is good. Also for wax esters, the agreeme nt was good, even if they were compared with results obtained from a q uicker method as reliable as the official one. The possibility of sepa rating the squalene isomers also at the same time makes the proposed m ethod more advantageous. On the whole, the method, which is suggested for routine and quick screening but not for the exact evaluation of th e analyte contents, seems to be a convenient choice for ascertaining o n a daily basis the samples' legal compliance (i.e., whether the analy te content is or is not below the legal value).