Validación de métodos analíticos para la determinación de pH, conductividad y la capacidad de intercambio catiónico total por el método de acetato de amonio en suelos

Abstract

The present research work was developed in the soil analysis laboratory located in the faculty of Chemical Sciences, having as a main objective validating the analytical methods for the determination of pH, electrical conductivity and the total cation exchange capacity by acetate ammonium method in soils whose purpose is validating these methods so that in future the laboratory can offer it as a public service, guaranteeing the reliability of the results using validated methods. To achieve this goal several quantitative tests were carried in order to verify the validation parameters, which corresponds to precision, accuracy, detection limit and quantification limit. This work has as results for the validation of the pH method precision <1% of coefficient of variation; accuracy <1,5% error; LD 0.03 and Lc 0.05. For the validation of conductivity there is a precision of <2% of the coefficient of variation; accuracy <4,5% error; LD 0.003 and Lc 0.005 and for the total cation exchange capacity method, a precision of <6% coefficient of variation is obtained; accuracy <1,5% of recovery, LD 0.5 mg/L and Lc 1,65 mg/L. Soil analysis of pH, conductivity and total exchange capacity have been compared with the results presented by the Gruentec and INIAP accredited laboratories. The results of the analyzes achieve the goals set in validation, that is the reason why the methods of pH, conductivity and total cation exchange using the ammonium acetate method are declared successfully validated.