[bobs]

I am running gradient 5 to 95% organic (0.1% formic acid in ACN) using varion RP C18 column i am not be see the peak of sesquiterpene hydrocarbon epi aristolochene a sesquiterpen hydrocarbon..is this compound will not come out with this gradient? is it too greasy to come out? i am using shimadzu IT-TOF with shimadzu LC.
follwing is the link for chemical structure of compound which i can not paste here...
http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=50135472