The IT MS2 product-ion spectrum of the ion at m/z 1411.9 (a), and its MS3 product-ion spectra of the ions at m/z 1157 (1411 → 1157) (b), at m/z 1113 (1411 → 1113) (c), at m/z 1155 (1411 → 1155) (d), at m/z 1129 (1411 → 1129) (e), and at m/z 1141 (1411 → 1141) (f). The product-ion spectra from MS2 and MS3 confirm that the ion at m/z 1411 consists of a major 16:0-(19:0/16:1)-PIM2 structure and several monoacyl-PIM2 isomers.