AB Sciex QTRAP 4500 LC/MS/MS system, System User'S Manual, Page: 60 / 138

Operating Instructions — Acquisition Methods
4500 Series of Instruments System User Guide
60 of 138 RUO-IDV-05-0264-A
3 CE (Collision
Energy)
Compound The CE parameter controls the
potential difference between Q0 and
Q2 (collision cell). It is used only in
MS/MS-type scans. This parameter
is the amount of energy that the
precursor ions receive as they are
accelerated into the collision cell,
where they collide with gas
molecules and fragment.
Use the preset value and optimize for
the compound.
MRM, MS2,
Prec, NL,
and LIT
3 CES (Collision
Energy Spread)
Compound The CES parameter, in conjunction
with the Collision Energy (CE),
determines which three discreet
collision energies are applied to the
precursor mass in an Enhanced
Product Ion (EPI) or MS/MS/MS
(MS3) experiment when CES is
used. When a collision energy
spread value is entered, CES is
automatically turned on.
Use the preset value and optimize for
the compound.
EPI and
MS/MS/MS
4 CXP (Collision
Cell Exit
Potential)
Compound The CXP parameter is only used in
Q3 and MS/MS-type scans, where it
transmits the ions into Q3.
Use the preset value and optimize for
the compound.
Q3, MRM,
MS2, Prec,
and NL
4 TDF CE (Time
Delayed
Fragmentation
Collision Energy)
Compound This is the amount of energy that the
precursor ions receive as they are
accelerated into Q3, where they
collide with gas molecules and
fragment.
Use the preset value.
TDF
5 Q3 Entry Barrier Compound The Q3 Entry Barrier parameter is
used to transfer the ions from Q2 into
the LIT.
Use the preset value.
EMS, EMC,
EPI, ER, and
MS/MS/MS
5 Q3 Empty Time Compound The Q3 Empty Time parameter
controls the amount of time that
singly-charged ions are removed
from the LIT.
Use the preset value.
EMC
Item
Parameter Parameter
Type
Use Scan Type