Net analyte signal standard addition method for simultaneous determination of sulphadiazine and trimethoprim in bovine milk and veterinary medicines

► The spectra of sulphadiazine and trimethoprim overlapped in the range of 220-320 nm. ► Cloud point extraction used for extraction of sulphadiazine and trimethoprim in bovine milk. ► We used NASSAM as a chemometrics method to solve matrix effect and interferent errors. ► The limits of detection (LOD) for sulphadiazine and trimethoprim calculated as 0.86 and 0.92 μmol L−1 respectively.