[yang11225]

I am working on quantitation genotoxic compounds at ppm level, is there any one know which compound is good to use as external standard? This compound much be not too volatile for I have solvent delay for 5 mins. Thanks very much for the *delete me*!!

[marquis]

There are a lot of questions that come to mind.  I could ask for parameters, the specific drug assay and all that stuff.

The better way is to find an assay that is similar to the one you are doing.  There are many standard organizations that list these ( AOAC, USP, etc.). Check out the standard they are using and try it.

With out knowing the specifics, it would be bad to even make a suggestion.