WHAT IT IS
Collision energy is the amount of kinetic energy applied to ions as they pass through the collision cell in GC-MS/MS. It controls how strongly precursor ions are fragmented into product ions during collision-induced dissociation (CID).
Collision energy is a key parameter in Multiple Reaction Monitoring (MRM) methods. The correct energy setting ensures that target compounds produce abundant, stable, and specific fragment ions, which are essential for sensitive and selective quantification.
HOW IT WORKS
Precursor Ion Selection (Q1) – A specific ion from the analyte is selected in the first quadrupole.
Collision Cell (Q2) – This ion enters the collision cell, where it collides with inert gas molecules (typically argon or nitrogen).
Fragmentation – The energy of these collisions – set by the collision energy parameter – causes the precursor ion to break into smaller product ions.
Product Ion Detection (Q3) – The resulting fragments are filtered and detected in the third quadrupole.
The collision energy (measured in volts) directly affects which product ions are formed and how abundant they are.
IMPACT ON PERFORMANCE
Selectivity: Proper collision energy ensures the formation of specific product ions, helping to clearly distinguish the analyte from background noise or co-eluting compounds.
Sensitivity: Too little energy may result in incomplete fragmentation and weak signals. Too much energy may over-fragment the molecule, reducing the intensity of the desired ion.
Quantification Accuracy: Consistent and optimized fragmentation leads to stable and reproducible signal intensities, critical for calibration and quantitation.
Confirmation: Using multiple product ions (e.g., quantifier and qualifier) at optimized energies allows confident compound identification.