Consecutive Reactions Observed Using Floated Collision Cells

Sequential processes occurring in one field-free region of a sector-type mass spectrometer were observed by floating the collision cell. This way four overall processes were identified; (a) both processes occurring outside the cell, (b) both processes inside the cell, (c) the first process outside and the second inside, and (d) the first inside, the second outside the cell. Positions of these peaks are derived and several examples are shown (for CsI clusters, benzophenone and nitrobenzene). This is a unique technique for distinguishing sequential and one-step processes like the (sequential) loss of two monomers and loss of a dimer from a supramolecular cluster.