ECD base line Problem?

[rajdeeproy]

Dear all

Can ECD sensitivity get effected if samples are run with autozero enabled in the system.
I ask this question because my ECD base line is quite high at 89mv which was not there inititally. I have tried changing the oxy trap but it is not responding.

Please give me suggestion.

Best Regrads,
Rajdeep

[AICMM]

Rajdeeproy,

I would not necessarily say that AZ would limit sensitivity. However, if I assume that your full signal out is 1 Volt then you have eaten up at least 10% of you linear range if not more. Furthermore, if you normally run at a few mV as I suspect, the real issue is that your detector is probably dirty and THAT would cause a loss of sensitivity. You might try hydrogen cleaning your ECD if there are instructions on how to do that or you might send you ECD off to a reputable shop for cleaning or to PE for cleaning. I am not familiar with PE ECD but when the HP ECD is running about 10% of full scale, it desperately needs cleaning. Sorry bud.

Best regards.

[AICMM]

rajdeeproy,

Sorry, one other thing. Make sure you don't have a leak at the base of the detector or in the inlet. If you did, this would cause an elevated baseline but it would also cause significant baseline rise as the oven temp ramps up and you cook of column phase.

Best regards.