The performance of the Stepped Normalized Collision Energy technique is demonstrated with a mixture of four compounds: neocuproine [MH+=209], alpha-naphthylred [MH+=248], ellipticene [MH+=247] and triamterene [MH+=254], each having two or more aromatic rings. Each of these compounds has a different energy threshold for fragmentation. Using the standard NCE technique with a setting of 40%, alpha-naphthylred was completely fragmented, neocuproine was not fragmented at all and ellipticene and triamterene were barely fragmented. At a Stepped Normalized Collision Energy of 40% with 3 steps and a 20% window, all of the compounds including the neocuproine were fragmented (Figure 2). Using SNCE on this mixture resulted in better fragmentation efficiency for all of the compounds.

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