Chromatographic, titration and ion-selective electrode methods for chemical analysis of groundwater samples and their application on the cenozoic aquifer system in the Lower Tagus Basin, Portugal.

Abstract

The water monitoring is a growing need today which forces to a high number of analytic determinations that can be done by several analytical methodologies in result of the technological progress. The suitability of the analytic methods in each situation depends on what is intended to be analyzed and its required accuracy. Sometimes the choice is irrational. It depends on the familiarization of the person who is analysing with the technique and it can also depend on the laboratory equipment. This paper describes analytical methods to detect, identify, and quantify inorganic ions in groundwater samples. With the purpose of proceeding to the efficient chemical characterization of the water and at the same time to turn possible the comparison among results, a case of study is presented. At Almada region in the Tagus basin (Portugal) for groundwater characterization were used, with high accuracy results, chromatographic, titration and ion-selective electrode methods for the determination of nitrate, nitrite, chloride, sulphate, phosphate, fluoride, sodium, potassium, calcium, magnesium, bicarbonate, electrical conductivity and pH. Keywords: Ion chromatography, titration, ion-selective electrode, groundwater, cenozoic aquifer system, Lower Tagus.