High-throughput modified QuEChERS method for the determination of the mycotoxin tenuazonic acid in wine grapes.

ARIEL R. FONTANA; LUCIANA P. PRENDES; VILMA I. MORATA; RUBÉN BOTTINI

RSC Advances

Royal Society of Chemistry

Año: 2016 vol. 6 p. 95670 - 95679

A reliable, simple, fast, inexpensive and robustsample preparation approach for tenuazonic acid (TA) determination in grapes byliquid chromatography with ultraviolet detection (HPLC-UV) is proposed. Themethod is based on a modified QuEChERS (quick, easy, cheap, effective, ruggedand safe) approach using ethyl acetate as extraction solvent. Its involves extractionof 2.5 g sample (plus 2.5 mL 1% formic acid acidified water) with 5 mL of ethylacetate; drying/cleaning-up of extract with 0.25 g anhydrous CaCl2 anddetermination by HPLC-UV. The method was optimized and validated achieving alimit of quantification (LOQ) of 0.05 µg g-1. The overall recoverieswere 96 %, 82 % and 97 % for grape samples spiked at 0.05, 0.5 and 5 µg g-1,respectively. The method showed excellent reproducibility with RSDs for theabove data ≤ 8 % and Hortwitz ratios <0.11. The procedure was applied toevaluate the occurrence of TA in grapes and it was quantified at concentrationsranging between 0.057 and 0.595 µg g-1. The methodologicaldevelopment allows a high throughput routine quality control of grapes, addinga valuable tool for the winemaking industry. The method could be applied in an averagelaboratory and help to understand possible effects related to Alternaria rotting on the final wineselaborated. As well, this is the first report of TA presence in grapes used forwine elaboration, so the results add new knowledge to a growing research area.