Chromatographic Troubleshooting
Peak symptoms
CInteraction with column material is a frequent cause. Silanized support may help. An all•glasssystem may be required if metal column tubing is the source.
CColumn overload with a gas sample often shows this effect; try injecting less.
CThis may be a merged peak situation: Running at lower (30^C) oven temperature will increase resolution, perhaps enough to reveal merged peaks.
CLow inlet temperature may cause this, as can poor injection technique.
3.Top (apex) of the peak is deformed:
Figure
Detector Overload
CDetector overload is the probable cause: The distortion is not easily seen on the chart but reveals itself in an integrator report. In extreme cases, doubling amount injected causes little or no increase in peak size.
Inject less sample, or dilute it, whichever is more convenient (dilution is usually the best approach). Since the detector is at the upper limit of its response, substantial dilution (100 times or more) is needed to be well within normal operating range of the detector.
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