to clean or not to clean?

[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.?

[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.

[scbowman]

Can you recommend a company for that service?

[vballchemist]

We use CJ Bruyn & Co. in Ca.

http://www.cjbruynco.com

[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.

[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.