Agilent InfinityLab LC Series RID User Manual
78
5
Optimizing the Detector
Refractive Index Detector Optimization
Refractive Index Detector Optimization
Follow these thirteen points to optimize the performance of your refractive index
detector.
1
Position the solvent and waste reservoirs correctly
Position the solvent and waste reservoirs above the level of the refractive
index detector and solvent pump. This maintains a slight pressure in the
sample cell and will improve the performance of the detector.
2
Do not overpressurize the flow cell
Be aware to not exceed a 5 bar pressure drop after the flow cell when hooking
up additional devices like other detectors or a fraction collector. If an
additional detector is installed place upstream in the flow path it before the
refractive index detector.
3
Use the correct solvents
To minimize baseline noise and drift solvents must be LC grade and filtered
prior to use.
4
Check for leaks
Leaks within the LC instrument that the refractive index detector is connected
to will cause problems with baseline long term noise or drift. Confirm that the
instrument is free from leaks by performing the diagnostic pressure test (for
the high pressure parts of the system between pump and column). Ensure
that the connections from the on-line vacuum degasser to the pump and the
detector inlet, waste and recycle connections are air tight.
5
Verify frit, filter and fitting quality
Partially blocked frits, filters and fittings can cause baseline long term noise.
Verify that the pressure drop across all such parts is within expected limits.
NOTE
Depending on the detector different inlet tubings are used (from the Accessory
Kit):
•
G7162A:
•
Interfacing capillary (G1362-87300)
•
G7162B:
•
Capillary ST 0.075 mm x 220 mm (5067-4784) (Sampler to TCC/MCT)
•
Capillary ST 0.075 mm x 340 mm (5067-4783) (Column to RID)