Resolution of overlapped quaternary spectral bands by net analyte signal based methods; an application to different combinations in tablets and capsules

Abstract

Net analyte signal (NAS) based methods (NBMs); namely NAS preprocessing (NAP) and hybrid linear analysis (HLA) were applied as multivariate calibration methods for resolving quaternary spectrally overlapped bands of Chlorzoxazone (CXZ), Paracetamol (PAR), Ibuprofen (IBU) and Ketoprofen (KTO) which are commonly co-formulated. The calibration set was composed of 17 mixtures within the concentrations ranges of 8.80–13.20, 10.56–15.84, 7.04–10.56 and 1.76–2.64 μg/mL for CXZ, PAR, IBU and KTO, respectively. A wavelength selection procedure was presented for the introduced NBMs. Figures of merit as limit of detection, selectivity and analytical sensitivity were also calculated based on the NAS concept. The developed NBMs models used smaller number of wavelengths as well as smaller number of latent variables which make NAP and HLA models more simple and interpretable than the conventional partial least squares (PLS). The models were successfully applied to tablets and capsules, and ANOVA was applied in comparison with an HPLC method.