Dehmelt potential

Figure 2.27 displays this Dehmelt potential graphically as a function of qz, itself a function of V. 

Actually, when an ion produces fragments, they need to be efficiently trapped, which depends on the value of the Dehmelt potential. Otherwise, parts of the fragments are lost by lack of trapping efficiency. There is thus a compromise to find between loss of sensitivity and loss of lower m/z fragment ions. 

FIGURE 4.24 Scheme of the Dehmelt potential in a quadmpole ion filter and cylindrical FAIMS. 

---