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to clean or not to clean?
Posted: Wed Jul 13, 2005 6:00 pm
by scbowman
When do you know that you should send your ECD detector out for cleaning? I ask because we have been having a pretty consistent problem getting our standard checks to pass. The tend to increase to such an extent that they are outside QC criteria. We recently had a lot of work done on the GC itself resulting in a new inlet (liners, septa, housing, etc.) and new column and new gas lines, so I feel confident that they can be ruled out as the culprits. Is increasing signal of standards within a run a possible indication that a 2 year old ECD needs to be cleaned/repaired/etc.?
Posted: Thu Jul 14, 2005 2:06 pm
by vballchemist
Yes, this is exactly what happens. Depending on the usage of the instrument, ECD reconditioning may be needed anywhere from every 18 months to every 3 years. Foil replacement should only be needed after 10 years or if the ECD has been compromised.
Posted: Thu Jul 14, 2005 4:04 pm
by scbowman
Can you recommend a company for that service?
Posted: Thu Jul 14, 2005 5:05 pm
by vballchemist
We use CJ Bruyn & Co. in Ca.
http://www.cjbruynco.com
Posted: Thu Jul 14, 2005 6:31 pm
by JI2002
vballlchemist,
I heard most problems with ECD is anode contamination, it needs to be cleaned every a couple years, maybe. When you send ECD out for service, what exactly do they do for reconditioning? Thanks.
Posted: Thu Jul 14, 2005 6:53 pm
by vballchemist
Yes, this is correct. Typically, a good bake of the detector at 400C for a couple of hours can buy you some time - be sure Nitrogen or P5 flow is flushing the ECD while baking.
I believe the anode is "cleaned" and the rest of the ECD that is in contact with the sample is cleaned. I do not know, specifically, the procedures used. I do know that these are sealed units and the party cleaning the ECD needs to have a current radioactivity license.
You may want to contact CJ Bruyn to get specific questions answered.