I have very limited experience in GC (all HPLC). Can anyone advise on analysing quantitatively for the compounds 4,7-Diphenyl-1,10-Phenanthroline and Hydroquinone. The test solution will be a aqueous solution of dilute acetic and perchloric acid, containing about 25% ethanol. After passing it through a C18 Sep Pak Vac or a polymeric RP column to hopefully eliminate >99.9% of up to 10mg of each of these compounds. Any suggestions?