I am testing an ECD that has been sitting around for 5+ years with mixed results. The baseline seems ok ~90-110 on a 6890 GC. But the peaks from a simple TCE standard of 10ppm has yielded very broad peaks (about 6 minutes in width).
The method consists of:
6890 GC with EPC
carrier He = 1ml/min (have tried 0.5 to 4 ml.min) and the ret time changes but not the width
make-up N2 50 ml/min
anode N2 5 ml/min
oven 35 C to 200 C at 10 oC/min
split ratio, 20:1 (tried 10:1, 5:1 as well)
If there is something obvious I am missing here, I would appreciate any comments...
By Jason Ellis on Thursday, March 18, 2004 - 04:29 pm:
What type of column are you using? What are the dimensions of that column? There is a detector checkout procedure and standard that you could use to evaluate your instrument. The procedure can be found in your instrument operating manual. If you can't locate it, then please feel free to contact me directly.
By Anonymous on Friday, March 19, 2004 - 09:23 am:
DB5-HT column, 30m, 0.250mm, 0.1um
there is no ECD checkout procedure in the HP6890 Series GC Operating manual that I have.
Any help would be appreciated.
By Anonymous on Wednesday, March 24, 2004 - 01:05 pm:
Jobber and Jason,
If I remember right (may not be the case) but I think carbon disulfide will cause quite a response in the ECD, I think a different solvent is in order here.
By Anonymous on Thursday, March 25, 2004 - 04:53 am:
You are quite correct.
By Jason on Thursday, March 25, 2004 - 09:22 am:
Aaaaah, yep...you're right. Didn't catch that one the first time around.