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GC Inlet Maintenance

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Routine maintenance is an important step in getting the best performance from your gas chromatograph. There are numerous parts just in the inlet that require regular replacement including inlet liners, liner O-rings, septa, ferrules, and, for some instruments, inlet seals. Replacement schedules can vary depending on samples and run conditions, but you will reduce your need for troubleshooting when you get your systems on a preventative maintenance schedule. Components and steps may vary based on the instrument or its configuration. Your instrument manual is always the definitive source of instructions.  

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Hello, and welcome to another Restek Tip. In today’s tip, we will be covering GC inlet maintenance. So, for many labs out there who are running complex samples with dirty matrices, you’ve probably experiencing your chromatography getting worse over time. This comes in the form of loss of signal or response, peak tailing, or extra peaks due to analyte breakdown. Chances are, you probably need to do some inlet maintenance, which will help your chromatography bounce back. To do this, we’ll replace a septum, inlet liner, and O-ring, inlet seal, and possibly cut a section of column to remove any residue buildup on the front end. First, we will cool our inlet and oven, as well as turn off the instrument flow. Once these have cooled, we will uninstall the inlet end of our column and trim it if needed. After this, we will replace the septum and remove the inlet liner and O-ring.

Next, using the appropriate-sized wrench, remove the inlet reducing nut so that the inlet seal can be replaced. Once the inlet seal has been replaced, and the inlet reducing nut has been reconnected, place a new clean liner and O-ring into the inlet. Our chromatography should be back to normal or looking much better. To prevent unwanted instrument downtime before a major problem occurs, I like to put my instruments on a preventative maintenance schedule. Once you understand the sample matrix you are working with, plan ahead by setting a routine schedule for replacing your inlet supplies. Keeping your inlet clean and happy will prevent frustration and allow you more time for analyzing samples. If you enjoy these videos, please like and subscribe. You can also share your own ideas for a future tip in the comments below. Thanks again for watching this Restek Tip.


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