Fumonisin monitoring in Thai red cargo rice by reversed-phase high-performance liquid chromatography with electrospray ionization ion trap mass spectrometry

The occurrence of fumonisins in red cargo rice from Thailand was studied by high-performance liquid chromatography with electrospray ionization ion trap mass spectrometry (LC-ESI-MS/MS). A quantification method for fumonisin B1 (FB1) was developed and the chromatogram of fumonisin B2 (FB2) was observed. The present method provides a sensitive detection limit at 1.0 ng g^-1. The limit of quantification was 5.0 ng g^-1. The recovery rate showed high yield of accuracy at 110.1±13.3, 89.3±11.1 and 91.9±4.6 % after fortification (n=5) at 50, 100 and 500 ng g-^1, respectively. Of the fifty eight samples from the retail markets, two samples were found to be naturally contaminated with FB1 at a trace level (lower than 5.0 ng g^-1). None of FB2 was found in any of the samples. This is the first report about the natural occurrence of FB in red cargo rice from Thai market.