Identification of New Geometric Isomers of Methyl Linoleate Hydroperoxide and Their Chromatographic Behavior

New geometric isomers, methyl (9Z,11Z)-13-hydroperoxy-9,11-octadecadienoate and methyl (10Z,12Z)-9-hydroperoxy-10,12-octadecadienoate, were proved to be present in methyl linoleate hydroperoxide produced by autoxidation. They were identified from their UV, MS, and 1H-NMR spectra after conversion to the corresponding oxo derivatives: methyl (9Z,11Z)-13-oxo-9,11-octadecadienoate and methyl (10Z,12Z)-9-oxo-10,12-octadecadienoate. Their chromatographic behavior is described.