Micromass Quattro Ultima, User Manual

Page: 126 / 227

Preparing for Calibration
Reference Compound Introduction
It is best to use a large volume injection loop (50µl) with a solvent delivery system set
up to deliver 0.2 ml/min of 50:50 acetonitrile:water or methanol:water through the
injector and into the APcI source. An injection of 50µl of reference solution lasts for
approximately 15 seconds, allowing enough time to perform a slow scanning
calibration.
Tuning
Before beginning calibration:
Set Multiplier to 650V.
Adjust source and lens parameters to optimise peak intensity and shape.
Set the resolution and ion energy parameters for unit mass resolution on MS1
and
MS2
.
When a full calibration is completed it is possible to acquire data over any mass
range within the calibrated range. It is therefore sensible to calibrate over a
wide mass range and in this example the calibration covers up to 1000 amu.
Calibration Options
To access the calibration options click on Calibrate on the acquisition control panel.
Selecting Reference File
Set pegh1000.ref as the reference file by clicking on the arrow in the reference
file box and scrolling through the files until the appropriate file can be selected.
Leave the Use Air Refs box blank when calibrating in APcI.
Removing Current Calibrations
Select uncal.cal from the File , Load Calibration... menu option.
Select Process , Delete all calibration... followed by File ,
Save Calibration
.
This ensures that a file with no calibration is currently active on the instrument
and prevents any previously saved calibrations from being modified or
overwritten.
Selecting Calibration Parameters
A number of parameters needs to be set before a calibration is started. Most of these
parameters can be set at the same value as for electrospray. However, a
Polynomial order of 2 is recommended for the calibration Curve Fit .
Mass Calibration
Page 126
Quattro Ultima
User's Guide