Investigating Results Issues - Thermo Scientific ISQ User Manual

Investigating Results Issues

Table 4. Troubleshooting Results Issues in Your Data (Sheet 1 of 2)
Behavior Characteristic
Low General
Reproducibility of
Peaks Area
Thermo Scientific
Cause
Detector gain is set too low Retune the gain.
Concentration is not
compatible with the
dynamic range of the
detection system
Chromatogram and
spectrum are blank
Injection technique is not
appropriate
Injection parameters are
not appropriate
Sample injection technique
is not reproducible
Syringe or septum is
leaking
Injection port is leaking
Injection technique is not
suitable
Ion source is dirty
Split flow or ratio control is
inadequate
Investigating Results Issues
Remedy
Increase the electron multiplier voltage.
Increase the target ion count.
Verify that the sample concentration is
suitable for the MS.
Make sure the tune file is correct.
Verify that the Busy light is on during
acquisition.
Make sure the filament is not burned
out.
Use a different injection technique.
Verify the injection temperature and
flow rates.
Evaluate the sample preparation
sequences.
Compare the results with a series of
standard injections.
Check and replace the syringe and/or
septum at regular intervals.
Check the column connections.
Run a leak check.
Carefully meter the injected amount.
Use a clean, good-quality syringe.
Clean the ion source and retune the
instrument.
Monitor the flow.
Replace the in-line filter.
ISQ User Guide
8
Troubleshooting
113