Riad S.M.Salem H.Elbalkiny H.T.Khattab F.I.Analytical Chemistry DepartmentFaculty of PharmacyCairo UniversityKasr-El Aini StreetCairo11562Egypt; Analytical Chemistry DepartmentFaculty of PharmacyDeraya UniversityMeniaEgypt; Analytical Chemistry DepartmentFaculty of PharmacyOctober University for Modern Sciences and Arts (MSA)October City11787 6thEgypt2020-01-092020-01-09201513861425https://doi.org/10.1016/j.saa.2014.12.104PubMed ID 25637816https://t.ly/yMKYpScopusFive, accurate, precise, and sensitive univariate and multivariate spectrophotometric methods were developed for the simultaneous determination of a ternary mixture containing Trimethoprim (TMP), Sulphamethoxazole (SMZ) and Oxytetracycline (OTC) in waste water samples collected from different cites either production wastewater or livestock wastewater after their solid phase extraction using OASIS HLB cartridges. In univariate methods OTC was determined at its ?max 355.7 nm (0D), while (TMP) and (SMZ) were determined by three different univariate methods. Method (A) is based on successive spectrophotometric resolution technique (SSRT). The technique starts with the ratio subtraction method followed by ratio difference method for determination of TMP and SMZ. Method (B) is successive derivative ratio technique (SDR). Method (C) is mean centering of the ratio spectra (MCR). The developed multivariate methods are principle component regression (PCR) and partial least squares (PLS). The specificity of the developed methods is investigated by analyzing laboratory prepared mixtures containing different ratios of the three drugs. The obtained results are statistically compared with those obtained by the official methods, showing no significant difference with respect to accuracy and precision at p = 0.05. � 2015 Elsevier B.V. All rights reserved.EnglishOctober University for Modern Sciences and Artsجامعة أكتوبر للعلوم الحديثة والآدابUniversity of Modern Sciences and ArtsMSA UniversityMean centering of ratio spectraOxytetracyclineSuccessive derivative ratioSulphamethoxazoleTrimethoprimWaste waterAgricultureExtractionMixturesPhase separationSpectrophotometersSpectrophotometryThermomechanical pulping processWastewaterOxytetracyclines (OTC)Ratio spectraSuccessive derivativesSulphamethoxazoleTrimethoprimLeast squares approximationsantiinfective agentoxytetracyclinesulfamethoxazoletrimethoprimwaste waterwater pollutantanalysisprincipal component analysisproceduresregression analysisspectrophotometryvalidation studywaste waterwater pollutantAnti-Infective AgentsLeast-Squares AnalysisOxytetracyclinePrincipal Component AnalysisSpectrophotometrySulfamethoxazoleTrimethoprimWaste WaterWater Pollutants, ChemicalArticlehttps://doi.org/10.1016/j.saa.2014.12.104PubMed ID 25637816