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LC UV Detector Issues

Description 

UV detectors are the most common type used in liquid chromatography. Many of us rely on them every day, but if you start to notice errors in your chromatogram, there could be a problem with your detector.  

In this Restek Tip, we look at some of the issues you might encounter with a UV detector. What should you look out for and what troubleshooting steps can you take? 

Additional Resources 

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Transcript 

UV detectors are the most common type used in liquid chromatography. Many of us rely on them every day, but if you start to notice errors in your chromatogram there could be a problem with your detector. 

In this Restek Tip, we’re going to look at some of the issues you might encounter with a UV detector. What should you look out for and what troubleshooting steps can you take? 

Drift, signal noise, or low sensitivity in your chromatogram may be the first sign of a problem with the UV detector. And one of the most common causes is cell leakage. 

Cell leakage can occur when there is a leak in the tube fitting that connects the column to the cell.  

We recommend that you stop the flow, push the tubing into the connection firmly, and retighten it. If the leak is occurring inside the cell, consult your user manual to check if the cell can be repaired with a rebuilding kit or if it requires service. 

If you’re seeing a loss in sensitivity, a dirty detector could be the cause.  

Depending on your specific detector, it may be possible to clean it, but keep in mind that there is a pressure limit on your detector cell. Check with your manufacturer before attempting cleaning as you could damage the detector. 

Detector issues can also cause baseline errors in your chromatogram: 

Noise spikes in your baseline can come from poorly degassed solvents, a failing lamp, or simply a dirty detector cell. Routine maintenance can help you spot these problems early and fix them before they become an issue.  

A gradual increase in baseline noise can be attributed to an old lamp or column contamination. The best way to avoid baseline noise is to use HPLC-grade solvents and degas them before use.  

It is also good to flush your column at the end of the day with a strong solvent, especially if you are using buffers or salt additives. While doing so, it is recommended that you remove the outlet tubing from the detector, so you don’t further contaminate the cell. 

Thank you for joining us for this Restek Tip! 

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