32nd ISCCRiva del GardaGC/MS Users Meeting
ISCC User Meeting
May, 2008Page 1
Agilent GC/MS Portfolio
Smallest footprint, single GC column
Power of MRM
Industry leading GC/MS System
5975C with 7890GC
7000A GC/MS/MS
5975VL with 6850GC
32nd ISCCRiva del GardaGC/MS Users Meeting
ISCC User Meeting
May, 2008Page 2
Agilent 7000A GC/MS/MS
Platform2.5 cm/ 1 inches
7000A Width36 cm/14 inches
5975: 31 cm/12 inches
32nd ISCCRiva del GardaGC/MS Users Meeting
ISCC User Meeting
May, 2008Page 3
GC/MS Triple Quad (QQQ)
DetectorQuad 1Mass
Analysis
Collision Gas (Ar, N2, He)
Quad 2 Collision
Cell
Ion Source•Ionize
Quad 3Mass
Analysis
Carrier Gas (He, H2 )
32nd ISCCRiva del GardaGC/MS Users Meeting
ISCC User Meeting
May, 2008Page 4
GC/MS Triple Quad (QQQ)
DetectorQuad 1Mass
Analysis
Collision Gas (Ar, N2, He)
Quad 2 Collision
Cell
Ion Source•Ionize
Quad 3Mass
Analysis
Carrier Gas (He, H2 )
Mean Free Path
Long LongShort
32nd ISCCRiva del GardaGC/MS Users Meeting
ISCC User Meeting
May, 2008Page 5
GC/MS Triple Quad (QQQ)
DetectorQuad 1Mass
Analysis
Collision Gas (Ar, N2, He)
Quad 2 Collision
Cell
Ion Source•Ionize
Quad 3Mass
Analysis
Carrier Gas (He, H2 )
Q1 Post-filter
Q2 Pre-filter
32nd ISCCRiva del GardaGC/MS Users Meeting
ISCC User Meeting
May, 2008Page 6
Agilent 7000 GC/MS/MS (QHQ)
DetectorQuad 1
Collision Gas (N2 )
Hexapole Collision
Cell
Ion Source•Ionize Quad 2
The hexapole field has excellent transmission efficiency for precursor and product ions
Q1 Post-filter
Q2 Pre-filter
32nd ISCCRiva del GardaGC/MS Users Meeting
ISCC User Meeting
May, 2008Page 7
What is MRM MS/MS?Multiple Reaction Monitoring
Product 3
Product 2
EI: many ions from the source
Product 1
EI-MS/MS
Q1 SIM isolate precursor before CID
CID + Q2 SIM
32nd ISCCRiva del GardaGC/MS Users Meeting
ISCC User Meeting
May, 2008Page 8
Why MS/MS?Greater Selectivity Than SIM
PrecursorIon
Product 1Product 3
Product 2
EI-SIMselectivity proportional to
spectral resolutionno selectivity against ions
with same m/z
EI-MS/MSPrecursor selectivity same as SIM
High probability that at least one product ion will be a unique dissociation product
of the precursor BUT not the interferenceinterference
analyte
interference
The precursor ion should NOT be used for ion ratios or quantitation since the interferences will
be the same as the SIM ion
unit mass resolution
32nd ISCCRiva del GardaGC/MS Users Meeting
ISCC User Meeting
May, 2008Page 9
Why MS/MS?Lower detection limits by reducing noise
EI: many ions from the source
Q1 SIM isolate precursor before CID
chemical noise eliminated
Product ion signal often decreases, but the percentage decrease in noise is much larger for real samples; S/N and detection limits improve
Product 1Product 3
Product 2
CID + Q2 SIM
Product ion measured against zero chemical noise
32nd ISCCRiva del GardaGC/MS Users Meeting
ISCC User Meeting
May, 2008Page 10
Why a GC/MS/MS System?
Allows for the selective quantitation of target compounds in high chemical background samples
Better S/N in complex matrices than can be achieved by single quadrupole scan or SIM approaches.
Newer regulations in some markets specify analytical power commensurate with GC/MS/MS
32nd ISCCRiva del GardaGC/MS Users Meeting
ISCC User Meeting
May, 2008Page 11
Why GC/MS/MS? A Picture Is Worth a Thousand Words
GC/MS/MS QQQ MRM
GC/MS Single Quad SIM
EI 100fg HCB in “DIRTY” Matrix
S/N: 116:1 RMS
100 fg HCB
MS SIM
MS/MS MRM
A chromatographer’s dream: single peak on flat baseline
32nd ISCCRiva del GardaGC/MS Users Meeting
ISCC User Meeting
May, 2008Page 12
Why GC/MS/MS? A Picture Is Worth a Thousand Words
GC/MS/MS QQQ MRM
GC/MS Single Quad SIM
EI 100fg HCB in “DIRTY” Matrix
S/N: 116:1 RMS
100 fg HCB
MS SIM
MS/MS MRM
A chromatographer’s dream: single peak on flat baseline
Top Related