Maintaining the flow cell
4-5
Flushing the flow cell
Flush the flow cell when it becomes contaminated with the residues of
previous runs and after each detector shutdown. A dirty flow cell can cause
baseline noise, decreased energy levels, calibration failure, and other
problems. Always flush and purge the flow cell as your initial attempt to
correct these problems.
You should flush the flow cell whenever
•
noise is higher than expected.
•
Raman signal-to-noise test results are not meeting specifications.
•
the detector fails to normalize.
If you use buffered mobile phase, flush it from the detector before
powering-off.
Tip:
Always use well-degassed eluents.
To flush the flow cell:
1.
Stop the solvent flow, and remove the column.
2.
Replace the column with a union or piece of tubing.
3.
Flush the detector with HPLC-quality water.
Caution:
To avoid damaging the flow cell during reverse flushing, do
not overpressure the cell.
Caution:
• If the flow cell will not be used for several days, flush it with the
clean mobile phase, such as a water/acetonitrile or
water/methanol, then cap the flow ports or dry the flow cell with
pure nitrogen or pure helium.
• To prevent flow cell failure, do not connect any tubing or device
that can create backpressure exceeding the flow cell’s maximum
rating of 3447 kPa (34 bar, 500 psi).
Caution:
If the mobile phase is not compatible with water, flush
with an intermediate solvent first.
Summary of Contents for 2489
Page 8: ...viii...
Page 32: ...1 16 Theory and Principles of Operation...
Page 134: ...3 66 Preparing the Detector...
Page 193: ...Warnings that apply to all Waters instruments A 9...
Page 204: ...B 6 Detector Specifications...
Page 220: ...D 14 Solvent Considerations...
