What can cause a dip before the samples/standards that is not a refractive index?

Document ID

Document ID TE7963

Published Date

Published Date 05/21/2019
Print
Question
What can cause a dip before the samples/standards that is not a refractive index?
Summary
Dips before peaks not caused by a refractive index
Answer
When a base line fluctuation or small dip/peak is visible before a sample and/or standards within Lachat data, the issue can also be a valve turning artifact. A valve turning artifact occurs when there is a back pressure issue which is momentarily relieved when the valve turns to load or inject. This can be caused by the valve itself but can also be the result of the back pressure from a clog, crimp, or waste line issue.

When the cause of a base line fluctuation or small dip/peak is not apparent, there is a simple way to determine if it is a valve turning artifact. Place the probe or sample into the carrier solution. Run a few injections and observe if the fluctuation occurs. If it goes away, the issue is likely a refractive index. If the fluctuation is still present, it is likely a valve turning artifact.

Was this answer helpful?

Submitting...
Thank you for your feedback!
There was an error with your submission. Please try again.