Validación de un método analítico para ocratoxina A en quinua usando HPLC- fluorescencia.

Abstract

The objective of this research was to validate an analytical method for OTA A (Ochratoxin A) in quinoa, using HPLC (High Performance Liquid Chromatography) by means of a fluorescence detector. The methodology applied consisted of 2 stages, in the first one, five calibration curves were elaborated with an OTA A standard of purity greater tban 98%, the dilutions of the standard were: 0.94; 1.89; 5; 7.5 and 12.5ug/Kg. Each standard was injected in triplicate on 5 different days. A linear regression analysis was applied to the data obtained from the first stage to determine the parameters of linearity, linear range, limit of detection and limit of quantification. In the

second stage, 45 quinoa samples were contaminated by adding 2, 5 and 12.Sug/Kg of OTA A. Toe reagents req uired for the ex:traction of OTA A were prepared, then the extraction was carried out in the 45 samples using the immunoaffinity columns. Purification, drying and placing in vials was carried out. Finally, the reading was perfonned in the HPLC equipment by means of the fluorescence detector. With the data from the second stage, the precision, accuracy (Cochran's statistic was applied), selectivity and uncertainty were calculated. Tbe results showed that the method is linear in arange of0.83 to 30ug/Kg; precise based on repeatability and reproducibility. The recovery level was 97.22%, limit of detection was 0.52ug/kg and limit of quantification was 1. 72ug/kg. Toe uncertainty was O. 86ug/kg. It is concluded that the method was validated for the

quinoamatrix. Jts use is recommended for the control of this contaminant in the quinoa production chain.