Simultaneous LC/MS analysis of hexachlorobenzene and pentachlorophenol by atmospheric pressure chemical ionization (APCI) and photoionization (APPI) methods.

The simultaneous LC/MS analyses of hexachlorobenzene (HCB) and pentachlorophenol (PCP), two dioxin precursors were studied by both atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization mass spectrometry (APPI/MS). The optimum LC/MS conditions of the simultaneous analysis were determined for these two compounds with different polarity. Ionization by APPI was found to be more effective than by APCI, and is thus a better ionization method for analysis of the two compounds. Using LC/APPI/MS we can achieve the simultaneous analysis of HCB and PCP at ppb levels.