Validación del método para determinación de detergentes en muestras de agua por espectrofotometría UV-Vis en el laboratorio AqLab de la ciudad del Coca

Abstract

The validation of the method for determination of surfactants in water samples by UV-vis spectrophotometry was carried out in the environmental analysis and evaluation laboratory Aqlab in the city of Coca. Its validation was carried out taking into account the analytical need of the laboratory, validation parameters of the INEN ISO IEC 17025 standard and SAE regulations, environmental regulations described in the TULSMA, in its Environmental Quality and Effluent Discharge Standard: Water Resource and the Municipal Ordinances of the Orellana Canton. The method 5540 C corresponding to the determination of anionic surfactants as MBAS described in the Standard Methods was used for the matrices of water for human consumption, natural water and waste water. The validation objectives were established and the corresponding experimental design was proposed under conditions of repeatability and reproducibility. The following parameters were analyzed: Response Function, Limit of detection, Limit of quantification, Precision (repeatability and reproducibility), Veracity, Uncertainty and Working Interval of the method. Through the statistical analysis of data, it was demonstrated that the method is suitable for the intended application, by meeting the validation objectives set for a CVr and CVR less than 30 percent for accuracy, a recovery percentage of 80 to 120 percent for veracity, an uncertainty U less than 30 percent with a 95 percent confidence interval (k is 2) and a method working range comprising concentration levels 0,10 to 8,85 ppm MBAS.