Determination of aflatoxin M1 in milk by triple quadrupole liquid chromatography-tandem mass spectrometry.

A sensitive and reliable method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with an electrospray-positive ionization method was developed for the determination of aflatoxin M(1) in milk. This method includes simple extraction of the sample with acetonitrile by ultrasonic, separation on an MGIII-C(18) column using 0.01% formic acid buffer/acetonitrile (60 : 40, v/v) as mobile phase, and MS/MS detection using multiple reaction-monitoring mode. Average recoveries of aflatoxin M(1) from spiked samples at concentrations of 0.02 and 1 ng ml(-1) ranged from 77% to 94%, with a 6% relative standard deviation. The limit of detection and limit of quantification were 0.006 and 0.02 ng ml(-1), respectively. The standard curve was linear between 0.02 and 20.0 ng ml(-1). The recommended method is simple, rapid, specific and reliable for the routine monitoring of aflatoxin M(1) in milk.