Molecular Ion Minus Fragment Lost 53 Chi c互=CHcH=c 55 CHa=CHCHCHa CHa-CHCH3CH3, CH3 CH=CHCH3, 2CO 58 NCs, (NO+ Co), CH3COCH3 59 CH3 CNH3 C3HgOH 五IacH [Has and CHa=CH=] 63 CHaCHa Cl CsH4, S2, SO? 68 CH2-C-CH=CH2 eEa·,CsH 73 CH3 CHa OC 74 CaLgON 75 C6H3 CsHs, Csh 78 C6H6, CSaH2, CsH4N Br. CsHsN 80 HBr CCIF CF?=CF. 19 CF3-CH 122 6Hs COOH ◆127 128