ANALYTICAL ADVANCES BASED ON FIRST-ORDER CALIBRATION MODELS AND UV-VIS SPECTROSCOPY FOR THE ASSESSMENT OF WATER QUALITY: A REVIEW – PART 1. This work aimed to infer about the scientific progress of the use of ultraviolet-visible (UV-Vis) spectrophotometry for evaluations of water quality. The research started in the 60s, when the imminence of obtaining characteristics of the UV-Vis spectrum that estimated the water quality. From a temporal perspective, the 1990s began using first order multivariate calibration models, focus of this work, to predict water quality parameters utilizing the UV-Vis spectra. During the period evaluated, numerous studies used spectrophotometry to quantify analytes using univariate calibration. However, many works also report the fact that the determined substances absorb at the same wavelengths and describe how to resolve these interferences. But gaps such as low concentration determinations are still a bottleneck as the best results, for example, are related to high amounts of organic matter, fact also related to instrumental aspects. One of the gains was the introduction of chemometric approaches which allows quantification without the need of analytical curve construction during the prediction step. However, although they are already used techniques, the survey carried out here verified the applications are considered incipient, where, for example, dissolved organic carbon and nitrate predictions using first order multivariate calibration represent less than 30% of the determinations.