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Pyrolysis GC or LC/MS?

Posted: Tue May 17, 2011 2:50 pm
by 135223395
Chlorinated hydrocarbons in soil can be analyzed by pyrolysis GC or by LC-MS. Why is pyrolysis GC preferred?

Help me, plzzzzz

Re: Pyrolysis GC or LC/MS?

Posted: Tue May 17, 2011 3:04 pm
by 135223395
Here is my teacher's hints, don't know what to do. >:( >:(

Rather than answer the question for you, let me ask some questions that will lead you to the answer.

What is the boiling point of 2,4-D and related compounds?
What is the solubility of 2,4-D and related compounds in common solvents?
How polar is 2,4-D? Is it a compound that would work well on normal phase LC? Reverse-phase LC?
If you can vaporize 2,4-D, what would a good GC column be? At what temperature would it run?
What interferents would pyrolysis eliminate? What interferents would be unaffected? Which would be enhanced?
What interferents would solvent extraction eliminate? What interferents would be unaffected? Which would be enhanced?
What detector would be best for the molecule in each system? What is the likely detection limit? What about selectivity?
Now, given the totality of the evidence, what are the chemical and physical reasons for choosing one method over the other?

Re: Pyrolysis GC or LC/MS?

Posted: Thu May 19, 2011 7:01 am
by DSP007
If you have LC-MS - you may use LC-MS. Its metod from this question - "fire of aircraft gun from small on the sparrow, small bird" But if you have gun an unlimited fire shorts - may fire.

But GC /from ECD detector/ - its good old method detection of pesticides, wary sensitive selective and quickly. You may be use non pyrolisis but solvent extaction and evaporated solvent concentration. See sea manuals (newslatter papers) from this method with 1951 for 2011 year. As we say in Russia "from the good deed goes unpunished"