Thiabendazole (TBZ) or tiabendazole is both a fungicide and parasiticide which goes by the trade names Mintezol and Tresaderm. As a fungicide, it controls mold and blight and as a parasiticide it can control various types of worms. According to the EURL-SRM (European Union Reference Laboratory – Single Residue Methods) TBZ is considered difficult to analyze by traditional multiresidue methods. We separated and analyzed TBZ using two mixed-mode columns with different modes of separation. Obelisc R has a long hydrophobic chain and multiple ion-pairing groups, and Primesep 100 contains acidic ion-pairing groups. Method is LC/MS compatible and can be use on many different pesticides.