Immunoaffinity functionalisation of coated blades for fast, specific and sensitive extraction and analysis of veterinary medicine.

Immunoaffinity-coated blades were prepared by covalently binding antibodies via carbodiimide coupling to carboxyl-modified polyacrylonitrile (PAN) coated metal blades. The application of these antibody-functionalised PAN blades was demonstrated using an immunoaffinity-coated blade extraction (IA-CBE) approach. The IA-CBE is used for extraction, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) for analyte detection. Blades were prepared targeting two model substances, streptomycin and dexamethasone, demonstrating rapid, highly selective extraction and detection of these substances below relevant maximum residue limits (MRL) and minimum method performance requirements (MMPR) from fortified bovine and porcine urine and kidneys. The performance characteristics of dexamethasone IA-CBE showed high sensitivity, good repeatability, and selectivity, and met the requirements for analyte confirmation as stated in relevant guidelines. Analysis of urine from a porcine animal treated with dexamethasone further demonstrated that the method is fit-for-purpose in real samples. This approach offers an efficient, fast, and highly selective solution for residue extraction in biological samples.