What experiment could be carried out to determine whether a DNA/RNA sample is contaminated with phenol?

I've carried out a spectrophotometry using the A260/A280 and have found the purity for my DNA and RNA samples, both samples were found to be within a pure range, i'm consierding they could be contaminated with phenol which would give a higher absorbencey thus giving them a higher 260:280 ratio, what experiment could be carried out to test if the DNA/RNA is contaminated with phenol? I'm considering the southern blot technique (due to differencies in m) but not entirley sure, any help would be great.