GC-microECD analysis question

Question

Hello All, 
 My lab has been trying to analyze fluorinated compounds in solvent on GC-uECD for a few weeks now and have noticed that the signal is very low compared to chlorine/bromine. I know that is to be expected, but it is so low sensitivity that it will be hard to analzye at any lower concentration. (Which will be necessary) 
 I am wondering if anyone out there has done work with fluorinated compounds on GC-ECD and has any advice. (Or knows whether or not this is feasible). 
 
 Thank you! 
 Madison Malone

Dr. Know · Accepted Answer

When I need information about detectors I use the following books: 
 
 Raymond P. W. Scott "Chromatographic Detectors - Design, Function, and Operation", Chromatographic Science Series Volume 73, Marcel Dekker, New York (1996). ISBN 0-8247-9779-5. 
 Raymond Annino, Richard Villalobos "Process Gas Chromatography - Fundamentals and Applications", Instrument Society of America (1992), ISBN 1-55617-272-9. 
 
 For the ECD there was also a separate Volume from J. Chromatogr. A, full of useful articles, (gave it to someone and never got it back :-( ) 
 
 
 
 Here are some pages from a presentation of mine. 
 I will add a Wiki article here in the Community in the Consumables area about the ECD, so please check every once in a while. 
 Norbert

Dr. Know · Answer

Hi Madison, 
 that is unfortunately true. Compared to chlorobenzene as reference fluoro-compounds range from 0.01 to 10 times the response, thus not very big, whereas chloro-, bromo- or iodo-compounds go up to 10000 times the response. If you have very low concentrations (and nothing very big in the mix) a PD-HID might give you better results, but it's easily overloaded and you might need some switching techniques. 
 Regards, 
 Norbert

malonemr76 · Answer

Thank you for your response. Is there any literature I can see on your reference of chlorobenzene? Asking as I would like to learn some more about it. (It is odd to me that Agilent's manuals do say that poly-fluorinated species see detects in the 10^7 Hz range - I have not seen that, and have asked Agilent application techs who have not seen it either) 
 Sadly, I believe you may be correct - we got this instrument as hand-me-down, and were hoping to use it as screening tool, while our high-use instruments run our grant work. Fluorinated compounds are currently our target of interest, but we may adapt down the line if there is a need.

GC-microECD analysis question

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