Chromatography Forum

Hi All,
Is it possible/advantageous to use LC-MS/MS for the analysis of PAHs?
Is there any standard method using LC-MS/MS for PAHs?

Thanks in advance!

Possible ?---yes (MAYBE). Advantageous ?---NO.

PAH's analyzed by LC/MS (ESI or APCI) give very stable [M+H]+ ions---difficult to fragment, especially to differentiate the isomers.

You might research APPI (atmospheric pressure photo-ionization) to see if that is more promising than ESI/APCI.

However, why re-invent the wheel ?---there are well-established EI/GC/MS methods, which have the advantage of very high plate counts of capillary columns to resolve the isomeric PAH's. There is also the matter of identification from an EI spectrum; there are commercial databases (NIST etc) for library search that are sold with GC/MS systems.

Thanks for your reply.
Actually, our GC-MS system is not behaving well with high molecular weight PAHs!!

Thanks for your reply.
Actually, our GC-MS system is not behaving well with high molecular weight PAHs!!

If it is loss of linearity have you tried the larger draw out plate for the ion source?(Assuming it is an Agilent)

Thanks.
It is an Ion Trap GC-MS. I get dirty chromatogram at temperatures around 300 oC and above.