Optimum Waveforms in Realistic FAIMS Regimes

FIGURE 3.15 Measured a2/a values for representative type B cations and anions amino acids (A, A), benzene and amines (+), ketones ( , o), organophosphorus compounds ( , ), and explosives (O). (From Shvartsburg, A.A., Smith, R.D., J. Am. Soc. Mass Spectrom., 19, 1286, 2008.) 

The situation with other gases is similar, and the typical a la and thus IarI values in some exceed those in N2. For example, field analyses often use ambient air which contains humidity that modifies a EjN) functions for all ions. At any water vapor pressure tried (from 120 to 6000 ppm), ions of four common explosives and their environmental degradants retained oi 0 and U2 0, and the maximum fl2/ i increased at higher humidity from 6 x 10 Td to 8 x 10 Td that leads to Or = —0.5 already at d/A= 80 Td.  

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