FIG. 6.

Tandem mass spectroscopic analysis of an ion with an m/z value of 1,013.1. (A) The MS² spectrum of an ion (m/z 1,013.1) from a reduced sample (Fig. 5) is shown. (B) The deduced structure and fragmentation pattern of the [M + H]⁺ ion is shown. Structure I shows the origin of fragments A through E and I. Fragments F through H, J, and K are the result of double cleavage events; the origins of these fragments are shown in structures II and III. Fragment B is not found in the scan shown in panel A but was present in others.