Application of dummy molecularly imprinted solid-phase extraction in the analysis of cyproheptadine in bovine urine

Due to the difficulty of monitoring trace levels of cyproheptadine (CYP) residues in complicated biological matrices, specific adsorption materials for the preconcentration and clean-up of CYP are indispensable. In this work, CYP was extracted from urine using dummy molecularly imprinted SPE (DMISPE) to avoid leakage of the imprinting molecules during the desorption phase. For synthesis of DMISPE, azatadine (AZA) was employed as the dummy template, methacrylic acid (MAA) as the monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linker, 2,2'-azobis(2-methylpropionitrile) (AIBN) as the initiator, and dichloromethane as the porogen solvent. An LC-MS/MS method was used to analyze CYP. Two MRM (multiple reaction monitoring) transitions for each analyte were monitored using diphenylpyraline hydrochloride (DPP center dot HCl), which was used as an internal standard. The advantages of DMISPE include obtaining less complex chromatograms and reducing ion suppression in ESI. The process efficiencies for DMISPE and SPE were 80% and 12%, respectively. In addition, the demonstrated reusability of the DMISPE cartridges is an advantage compared with single-use SPE cartridges or immunoaffinity materials.