Is there proof that benzoic acid is a byproduct of the degradation of XAD-2?

We do have several years of data showing that benzoic acid is a degradation product of the XAD-2 when exposed to stack gases.  Please refer to the answer to Question #11 for my explanation of the weaknesses of XAD-2 and how to minimize background contamination of XAD-2 in your sampling program.