Micromass Quattro Ultima, User Manual

Page: 104 / 227

Preparing for Calibration
Reference Compound Introduction
The example given here describes an automatic calibration which requires reference
compound to be present for several minutes. The introduction of the reference
compound is best achieved using a large volume Rheodyne injector loop (50 or 100µl)
or an infusion pump (for example, a Hamilton syringe pump).
When using a large volume injection loop:
Set up a solvent delivery system to deliver 4-5 µl/min of 50:50 acetonitrile:water
or 50:50 methanol:water through the injector into the source.
An injection of 50µl of reference solution then lasts for at least 10 minutes.
When using an infusion pump:
Fill the syringe with the reference solution.
Couple the syringe to the electrospray probe with fused silica tubing.
Set the pump to a flow rate of 4-5 µl/min.
Tuning
Before beginning calibration, and with reference solution admitted into the source:
Set Multiplier to 650V.
Adjust source parameters to optimise peak intensity and shape.
Set the resolution and ion energy parameters for unit mass resolution on MS1
and MS2 .
For a good peak distribution across the full mass range:
Check the intensity of some of the reference peaks above 1000 amu.
Check also the intensity of the peak at
m
173.
Ensure that no peaks are saturated. If necessary, reduce
Multiplier
.
A cone voltage in the region of 90 is usually suitable.
Mass Calibration
Page 104
Quattro Ultima
User's Guide