Development and validation of stable isotope dilution LC-MS/MS method for simultaneous quantification of four Alternaria toxins in 15 food commodities.

Alternaria toxins (ATs) are produced from Alternaria species that result in crop losses and harmful impacts on human health. A stable isotope dilution LC-MS/MS method was established to quantify four ATs in 15 food commodities: alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN), and tenuazonic acid (TeA). Based on systematically optimization of detection conditions and pre-processing steps, the limits of detection and limits of quantification of the four ATs ranged from 0.1 to 10 μg/kg and 0.2 to 30 μg/kg, respectively. The results showed that the recoveries of the four ATs were 72.0%-119.1%. The intra-precision and inter-precision ranged from 0.7% to 11.1% and 1.1% to 13.1%, respectively. The method was successfully applied to the determination of four ATs in 35 food samples, suggesting that this method could provide meaningful occurrence data to support the assessment of emerging ATs in food commodities.