DISMINUCIÓN DEL LÍMITE DE CUANTIFICACIÓN DE ALGUNOS ENSAYOS FÍSICO-QUÍMICOS DEL AGUA EN EL LABORATORIO DE ESTUDIOS AMBIENTALES DEL CEAC

Abstract

This study is aimed at the partial validation of physicochemical tests in water for visible ultraviolet
spectrophotometry (UV). This validation was performed using cuvettes of 5 cm thick and a Genesys 10 UV spectrophotometer. Validation parameters determined were linearity, repeatability, reproducibility, accuracy, quantification limit, uncertainty and expanded uncertainty, as outlined in the International Standard (TS-368 CN: 2004 Guide for the validation of test methods for food chemicals). All validation parameters tested met the requirements regulated, ensuring greater reliability in laboratory analytical work. Also able to reduce the limit of quantification for all validated assays, which allows to
determine concentrations of interest for ecological research. High limits of quantification assays for the
determination of nitrite, nitrate, orthophosphate and hexavalent chromium have prevented the quantification
of chemical species in water bodies such as the Bay of Cienfuegos and some reservoirs in the province. This work aims to validate these tests in order to lower the limits of quantification, and deliver information to facilitate the ecological interpretation of the results of the tests.
Keywords: validation, water, limits of quantification, spectrophotometry.