Thermo Finnigan LTQ - Page 41

Introduction
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____________________________________________________________ Ionization Techniques
_______________________ Finnigan LTQ Hardware Manual _____________________
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Figure 1-5. Energetics of photoionization
Figure 1-6. Illustration of selective photoionization
Photoionization
Gases in air,
solvent molecules
Fragment ion
thresholds
Molecular ion
thresholds
Drugs and other
compounds
Energy
Photoionization
hν
Threshold
H
2
O, CO
2
, O
2
, N
2
Drugs
Steroids
MeOH, AcCN
Chlorinated-solvents
Ionized Not Ionized
Agricultural
compounds
Threshold
H
2
O, CO
2
, O
2
, N
2
DrugsDrugs
Steroids
MeOH, AcCN
Chlorinated-solvents
Ionized Not Ionized
Agricultural
compounds
Agricultural
compounds
Threshold
Not IonizedIonized