Provided are methods for identifying OP-adducted biomarkers of OP exposure as well as compounds containing OPs that can provide OP adducts and compounds of Formula 1 for eliciting antibodies that specifically and selectively bind to the OP adducts, wherein the Formula 1 compounds have the structure of OP-Peptide-Linker-CP, wherein CP is a carrier protein, OP represents a structure corresponding to that of a reactive organic phosphorous compound covalently modifying a tyrosine residue hydroxyl group of the peptide of Formula I and the other variable groups are as described herein.