Shimadzu GCMS-QP2010 Series, Service Manual, Page: 52 / 168

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4.2 Checking the medium mass-number range (169, 219)
The medium mass-number range is adjusted using AC1, AC Coeff, and RES Coeff
parameters.
Fig. 4-3 Insufficient AC Fig. 4-4 Appropriate AC Fig. 4-5
Excess AC
At m/z 219 and 169, the peak separation of isotopes deteriorates with insufficient AC,
as shown in Fig. 4-3. With excess AC, a ridge appears before the peak, as shown
in Fig. 4-5, and signal strength (sensitivity) deteriorates. If the m/z169 peak width
(FWHM) becomes too small, adjust it by decreasing RES Coeff.
The peaks appear as shown in Fig. 4-4 when the AC1, AC Coeff, and RES Gain
parameters are adjusted correctly.
5. When the checks are complete, confirm that FWHM lies in the range 0.6
±
0.05AMU.
6. Close the window after the adjustments are complete.
7. The set values are automatically stored in the instrument EEPROM.
8. When the adjustments are complete, run GCMSsolution and conduct auto-tunig.