martes, 18 de junio de 2013

A new methodology can detect Patulin in apples at very low concentrations

Almost fifty percent of the apple juices tested were found contaminated

Patulin (PAT) is a mycotoxin naturally found in fruits, including apples. Its occurrence as a natural contaminant of fruit juices is indicative of fruit quality in production. The European Union has set the maximum content of patulin in 50 mg kg1 for fruit juices and 10 mg kg1 for infant fruit juices.

In this paper of Víctor-Ortega et. al, dispersive liquid-liquid micro-extraction (DLLME) has been proposed for the extraction and pre-concentration of PAT in apple juice, followed by its determination by micellar electrokinetic chromatography (MEKC) with diode-array detection. PAT has been analyzed in the presence of 5-hydroxymethylfurfural (HMF), which is the main interference in this kind of matrix.

Variables affecting DLLME efficiency were optimized and the calibration curve was established for PAT in analyte standard solutions, applying the DLLMEeMEKC procedure. The limit of detection was 0.6 mg L1 and recoveries obtained for spiked freshly-made apple juice samples at four different concentration levels (5, 20, 50 and 75 mg L1), were above 75% with RSD lower than 9%.

This method can be classified as a green alternative, being successfully applied to the measurement of 19 apple juice samples obtained from different suppliers and supermarkets. 

The optimized DLLMEeMEKC method is free from matrix effects and avoids the tedious matrix-matched or standard addition calibration method. Almost fifty percent of the samples were contaminated with a PAT content greater than the maximum content established by the European regulation.

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