DIFFERENT DETECTION SYSTEMS FOR THE HPLC ANALYSIS OF OXYLIPINS, BY-PRODUCTS OF THE ENZYMATIC GENERATION OF 2E-HEXENAL

The incubation of 13-hydroperoxy-9Z,11E,15Z-octadecatrienoic acid (13- HPOT) with a hydroperoxide lyase containing extract of mung bean seedl ings (Phaseolus radiatus L.) led not only to the formation of 2E-hexen al, but also to the generation of several non-volatile by-products (ox ylipins). These oxylipins, generated by the catalysis of other 13-HPOT metabolizing enzymes, were analyzed by high performance liquid chroma tography (HPLC) without time-comsuming derivatization procedures, whic h would be necessary for their volatilization and stabilization during gaschromatography (GC). Different detection systems such as an evapor ative light-scattering detector (ELSD), diode-array detector (DAD), an d particle beam-mass spectrometry (PB-MS) were applied. The utilizatio n of an ELSD represented an improvement of sensitivity compared to a D AD, especially in the case of substances with low UV-activity.