This paper summarizes the development of a new method for screening petroleum crude oils for the presence of "ARN" tetraprotic acids, based on molecularly imprinted polymers (MIPs). When slurried with crude oils, MIPs imprinted by a suite of ARN acid standards selectively bind to ARN acids. The strong interaction enables removal of most of the crude oil by several toluene washes. The ARN acids are then recovered by washing with a mixture of 5% formic acid in methanol/toluene. Our results show that the sample load directly impacts the amount of ARN acids recovered: a higher sample load lowers the detectable concentration range. MIPs offer a quick and sensitive method to screen crude oils for ARN acid present at low concentrations (sub-parts per million). This study also illustrates the capabilities of MIPs for isolating members of an entire class of compounds.