"Quenching" a sample of solution

[MedPR]

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Not sure what this means. Actually, I have no idea what it means. This is in regard to measuring reaction rates via gas chromatography.

From TBR:

Aliquots can be collected at uniform intervals and analyzed using GC. This requires mremoving some of the reaction mixture while the reaction is still proceeding, but the amount is generally so small that it has a negligible effect on the rate of the reaction. A bigger problem is that the reaction may continue to react in the syringe or pipette after it has been removed from the original flask. To avoid this problem, the sample of solution is quenched upon removal (to prevent further reaction). Once the samples are quenched, they are analyzed by a quantitative technique, such as GC or NMR.

Quenched?

 

[milski]

Not sure what this means. Actually, I have no idea what it means. This is in regard to measuring reaction rates via gas chromatography.

From TBR:



Quenched?

One of the reactants is neutralized by adding something that quickly reacts with it. For example, a bromination reaction can be 'quenched' by adding sodium bisulfite - the sodium bisulfite reacts with the bromine and stops any further bromination.

 

[MedPR]

So you have to be sure to add something that only reacts with one of the reactants in the sample, otherwise your data will be really screwed up/

 

[milski]

So you have to be sure to add something that only reacts with one of the reactants in the sample, otherwise your data will be really screwed up/

As long as it stops them reacting with each other and you're able to separate the original product, you're good. But you're right, typically it will be only one of the reactants that is being 'quenched.' And it certainly should not react with the product.