Page 10 - CRFTApplication Compendium_090613

6 Development of a Method for Evaluation of Mass Spectrometer Performance in Real Time
Conclusion
 A research method has been developed to evaluate the health or status of a
mass spectrometer in real time while performing routine quantitative analysis
 This method can be used to flag suspicious data or to reduce or remove the
need for manual review. Other possible outcomes are automated initiation of
system evaluation and/or system tune and calibration
 The method is constructed to avoid any negative impact on quantification,
particularly are the limits of quantitation.
drifts, the observed response in the analyte and internal standard responses are shown in
table 3. This can help to elucidate the cause of a change in internal standard.
Figure 8 shows a series of injections representing Q3 resolution/mass drift across the
range. The induced drift represents a Q3 mass position moving from 96 to 97.12 Da and an
associated change in peakwidth from 1.29 down to 0.11 Da FWHM. The effect on the
analyte and internal standard response are shown in table 4.
The output of these measurements are placed in an instrument database. These results,
and evaluation with respect to the given tolerances, are interpreted by the application
software. Responses can be limited to: a) simply alerting the user to the failure; b) provide a
snapshot of the instrument state at the moment of failure; c) aiding in data evaluation during
manual review; d) automatically rejecting data and remove the need for manual review; e)
rerun of the sample; f) triggering a system evaluation, an automatic recalibration and / or
triggering a series of self-diagnostic routines to fully evaluate and respond to the failure. In
the extreme, the response may go to the extent of alerting the operator and service
organization that a failure has been detected and needs attention.
Method Complexity
The method is constructed to allow full characterization of the analyte ions without
compromise, while taking a portion of the internal standard time to evaluate the precursor
and product ions. To this end, limits must be placed on the number of internal standards
that can be used at any given time with respect to the analyte ions.
In general two ISV ions with four quantitative ions (eight transitions) is the practical limit of
the method as it is currently implemented. This limit can be relaxed for wider
chromatographic peaks or must be tightened for faster chromatography.
of failures were induced in the mass
detect these situations. Figure 7
s drift across the peak. The induced
293.7 to 292.5 Da. As the mass
Standard for simulated Q1 mass
IS. Expected values and
TABLE 4. Effect on Testosterone and Internal Standard for simulated Q3
resolution and mass drift.
h Area M/Z Width Area
0.75 231442 97.23 0.68 13568
0.81 221995 97.22 0.62 14817
0.78 229631 97.22 0.71 15039
0.82 212293 97.21 0.73 13212
0.84 202647 97.23 0.76 13327
0.81 215050 97.20 0.70 11670
0.79 242640 97.21 0.71 14245
0.73 271143 97.21 0.71 16265
0.81 210047 97.22 0.67 13511
0.73 198064 97.23 0.69 13579
0.76 252640 97.21 0.72 17258
0.76 218588 97.22 0.66 13602
0.86 254163 97.24 0.75 16117
0.84 230583 97.20 0.74 14974
0.83 193470 97.21 0.69 9932
0.75 203190 97.23 0.77 12087
0.83 168075 97.20 0.63 9974
0.78 163832 97.25 0.73 9507
0.79 237080 97.22 0.73 14948
0.69 239721 97.21 0.65 14157
0.80 195292 97.22 0.68 12073
0.75 185614 97.22 0.77 11653
0.82 227182 97.22 0.72 14333
0.76 205373 97.20 0.72 12130
0.83 190210 97.20 0.78 11908
0.88 171022 97.20 0.74 11208
0.88 169641 97.22 0.72 11265
0.85 137600 97.20 0.74 7165
0.90 144843 97.19 0.67 9442
0.85 121133 97.19 0.67 8480
200000 97.2 0.7 12500
50000 0.1 0.1 3125
150000 97.1 0.6 9375
250000 97.3 0.8 15625
tation
nt Product
Conc
fg/uL Analyte nternal Std Resp/IS M/Z Width Area M/Z Width Area
400 129983 4524398 292.51 0.83 233924 96.97 1.29 78059
400 81433 2660164 292.51 0.79 183366 97.02 1.22 52724
400 62903 2114164 292.51 0.86 199773 97.06 1.16 42173
400 71324 2315379 292.53 0.87 229089 97.12 0.87 38967
400 37355 1268617 292.51 0.80 212764 97.12 0.71 23975
400 25779 813788 292.52 0.85 227637 97.22 0.66 15397
400 15637 550496 292.51 0.88 225702 97.25 0.63 9629
400 7182 259348 292.67 0.73 204002 97.30 0.69 5379
400 2169 77429 292.68 0.90 189833 97.32 0.11 1689
400 572 19136 292.67 0.73 196620 97.27 0.15 400
400 200 6462 292.67 0.76 208027 97.12 0.11 120
400 ND ND 292.66 0.74 231238 ND ND ND
400 ND ND 292.67 0.85 232639 ND ND ND
ISV Table for Demonstation of Q3 Resolution Drift
Response Parent Product
Area M/Z Width Area
D ND ND ND
28377 97.21 0.71 1768
203190 97.23 0.77 11695
178890 97.23 0.77 12729
214418 97.24 0.72 15903
69596 97.24 0.73 3798
5000 ND ND ND
f Q1Mass Drift
Product
Figure 8. Simulated Q3 resolution / mass drift.
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