HPLC-APCI-MS/MS using tropylium cation as a sensitizing agent has been applied
for the detection of standard PASH compounds: DBT, 2-DBT, 4,6-DBT, TAN and
BNTP. The HPLC approach relied on the separation of the PASH compounds according
to ring size on an amino bonded phase column. Fractions containing the 3-and 4- ring compounds were isolated then separated on a PRP (polystyrene divinyl benzene) column.
Post-column addition of tropylium after the PRP column, but just before the APCI source
of a Finnegan LCQ ion trap mass spectrometer allowed for the detection of organosulfur
compounds. Tandem mass spectrometry was performed to study the fragmentation
patterns. An Arabian crude oil was fractionated and previously unidentified compounds