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MRM: Multiple Reaction Monitoring
This mode is the MS-MS equivalent of SIR (Selected Ion Recording). As both MS1
and MS2 are static, this allows greater “dwell time” on the ions of interest and
therefore better sensitivity (~100×) compared to scanning MS-MS.
Typical application:
•
Rapid screening of “dirty” samples for known analytes.
Drug metabolite and pharmacokinetic studies
Environmental, for example pesticide and herbicide analysis.
Forensic or toxicology, for example screening for target drugs in sport.
Example:
Monitor the transition (specific fragmentation reaction)
m
609
→
195 for
reserpine in electrospray positive ion LC-MS-MS mode.
The result:
MRM does not produce a spectrum as only one transition is monitored. As in
SIR, a chromatogram is produced.
Instrument Description
Page 21
Quattro Ultima
User's Guide
MS1
static at m/z 609
(parent mass)
MS2
static at m/z 195
(daughter mass)
Collision Cell
RF only
(pass all masses)
LC-MRM
!
!
High specificity
Good signal / noise
LC-MS
!
!
Low specificity
Poor signal / noise
Time
Time
Содержание Quattro Ultima
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Страница 100: ...Data Acquisition Page 100 Quattro Ultima User s Guide...
Страница 117: ...Mass Calibration Page 117 Quattro Ultima User s Guide...
Страница 140: ...Mass Calibration Page 140 Quattro Ultima User s Guide...
Страница 212: ...Maintenance and Fault Finding Page 212 Quattro Ultima User s Guide...
Страница 222: ...Reference Information Page 222 Quattro Ultima User s Guide...