GREEN CHEMOMETRIC ASSISTED SPECTROPHOTOMETRIC METHODS FOR DETERMINATION OF CIPROFLOXACIN, METRONIDAZOLE, AND INDOMETHACIN RESIDUES IN PHARMACEUTICAL INDUSTERIAL WASTEWATER EFFLUENTS

Development and validation of three simple, eco-friendly, accurate and precise chemometric models have been presented for the spectrophotometric determination of ciprofloxacin (CIP), indomethacin (IND), and metronidazole (MET) residues in production wastewater samples. These methods are classical least square (CLS), principal component regression (PCR) and partial least square (PLS-1). A 3-factor 5-level experimental design was built leading to 25 mixtures containing different ratios of CIP, MET, and IND. Thirteen mixtures were used as a training set, and the other twelve were used as a validation set. Using of multi-wavelengths instead of the single wavelength spectrophotometry has greatly improved the precision and predictive abilities of these multivariate calibrations. The proposed methods have been found to be accurate, precise and can be used for determination of the drugs in pure form and industrial wastewater samples without preliminary separation steps. The methods described were used to accurately assess the drug residues in laboratory-prepared mixtures and actual industrial wastewater samples to confirm that it is free from these drug residues so it can be recycled and used for irrigation and other purposes.