Simultaneous determination of sulfadiazine, doxycycline, furaltadone and trimethoprim by partial least squares multivariate calibration

Quaternary and ternary mixtures of doxycycline (DX), sulfadiazine (SD), furaltadone (FT) and trimethoprim (TM) were determined by application of a multivariate calibration model. Partial least squares (PLS) methods were applied. The optimized model allowed the simultaneous determination of DX, SD, FD, and TM in artificial mixtures and in milk, and also, the simultaneous determination of SD, FT and TM in artificial mixtures and in a veterinary formulation.