Development of new dispersive liquid-liquid microextraction technique for the identification of zearalenone in beer

A method has been developed for the quantification of zearalenone (ZEN) in beer, using dispersive liquid-liquid microextraction (DLLME) followed by high performance liquid chromatography (HPLC). The optimisation of the method was performed using both high performance thin layer chromatography using a TLC-scanner and HPLC. Chloroform was used as the extraction solvent, and acetonitrile as the dispersive solvent. Under the optimum conditions, the enrichment factor for ZEN was 43.3 and the extraction recovery was 83%. Validation was performed for a working range of 0.4-120 pg mu L-1 ZEN. The limit of detection was 0.12 pg mu L-1. The recoveries of the method for ZEN from beer samples at 10 and 20 pg mu L-1 spiking levels were 71-108%. Different brewing styles of thirteen commercial beer samples were analysed, and ZEN was detected in 11 beer samples.