The applicability of a photoionization detector for small-bore packed-column supercrit. fluid chromatog. detn. of polycyclic arom. compds. in marine sediments was examd. The sepn. column was packed with Spheri-5 silica. Decompression at the entrance to the ionization chamber avoided the problems assocd. with high-pressure cell design and the quenching of ionization by the carbon dioxide carrier fluid. Advantages of photoionization over flame ionization detection included the added selectivity and sensitivity of photoionization toward arom. compds. as well as detector stability when subjected to high gas flow-rates. ; Peer reviewed: Yes ; NRC publication: Yes