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Divide & Conquer Troubleshooting

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A mixture of fundamental knowledge and appropriate application of helpful techniques is the recipe for successfully troubleshooting gas chromatography. One of the challenges of troubleshooting is that you can look in so many areas for causes of your problem. Divide & conquer is a tool that is used to try to quickly limit the possible sources of your issue, so you can quickly narrow your focus and then find and fix the problem. 

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Hi and welcome to this Restek Tip. So, your data or your instrument, or both, are telling you you've got a problem somewhere. You have to do some troubleshooting. Now, the first step for any trouble shooting is to get an accurate description of the problem that you are seeing. However, we all know that a given problem could conceivably actually stem from a variety of sources. So how do you know where to focus your attention when you are doing troubleshooting? This is where a troubleshooting technique called divide and conquer can really come to your assistance.

Imagine your instrument as a series of components, and your process as a series of components, working together to produce your data. If you can begin to isolate those components and interrogate them individually, you can figure out where your problem is and focus your troubleshooting attention.

So let me give you some examples. Take, for instance, you have an extraneous peak and you don't know where it's coming from. You might, for instance, go and spend a lot of time on your sample handling and preparation and syringes and rinse vials, but before you do that, let's figure out if the peak is in the instrument, coming from the instrument, or coming from outside of the instrument. And to do that, for instance, we could run a no injection instrument blank where you don't make any injection at all. If the peak is still there then you know you have to focus your efforts somewhere probably in the inlet. If it isn't, then now you have to focus your attention outside of the instrument.

Or take for instance, if you happen to have a situation where you have a two channel instrument where both channels are configured the same, say a split splitless to an FID both in the front and the back. If you're experiencing a problem in the front, say, you might want to first switch the detector ends of the columns so the front column is going into the back detector and now the back column is going into the front detector. Rerun your analysis. If the problem stays with the front detector, well you've changed everything else. It's the only thing that's the same. And so, chances are, that's where your issue is. But if it suddenly hops to the back detector, now you've said, “It's probably not my detector. It's probably my column or my inlet.” So, divide and conquer can really help focus your troubleshooting efforts. And good luck. And thanks for joining us for this Restek Tip.

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