Least squares versus derivative spectrophotometrie methods: determination of veterinary sulfa drugs

Least squares methods; namely, classical least squares, Kalman filtering and partial least squares were compared for the analysis of normal and derivative absorption spectra of some veterinary sulfa drugs in two different calibration designs and in two sets of wavelength range. Significant advantages have been found by the application of the derivative technique coupled with the partial least squares method. These results have been further compared with those obtained by official methods