Validación del método para la determinación de vitamina C (ácido ascórbico) en alimentos por Cromatografía Líquida de Alta Eficacia (HPLC)en el laboratorio ECUACHEMLAB Cía. Ltda.

Abstract

Validation of a method is an important requirement to ensure reliable and reproducible results from test laboratories. Validation was performed using the methodology described by AOAC 967.21, supplemented with the methodology (Ledezma - Gairaud, 2004), under ISO / IEC 17025. The developed method produces a linear response with a correlation coefficient r = 0.999 for each curve Calibration, LD equal to 0.0002 mg / ml and LC equal to 0.007 mg / ml. The working range comprises values from 0.007 mg / ml to 0.1448 mg / ml for the concentration of ascorbic acid ranging from 7.25 mg to 142.73 mg of vitamin C per 100 g of sample. The coefficient of variation was less than 2 percent for repeatability and reproducibility. The percentage recoverability was found in the range established for HPLC with a value equal to 99.32 percent. The limits of repeatability and reproducibility with values of 2.16 mg / 100 g and 2.61 mg / 100 g of ascorbic acid, respectively. The combined uncertainty of the method for all concentration levels employed with a value equal to +/- 0.95 and the expanded uncertainty with a value equal to +/- 1.91 expressed in units of mg of vitamin C per 100 g shows; It was used as an acceptance criterion that the value of the uncertainty is less than 30 percent of the low range resulting in the uncertainty found 26.31 percent, thus fulfilling the objective of validation.