Rapid Analysis of Aflatoxins(B_1,B_2,G_1,G_2) in Grain by Immuno-affinity Clear-up Column and Ultra Performance Liquid Chromatography without Derivation
A rapid and environmental-friendly analytical method without any derivation was established for the determination of aflatoxins(B1,B2,G1,G2) in grain samples.The samples were extracted by methanol-water,cleared up with the immuno-affinity column(IAC).The separation of target compound was performed on a Waters Acquity UPLC BEH C18(50 mm×2.1 mm,1.7 μm) using methanol: water(40 ∶ 60,V/V) as mobile phase with a flow rate of 0.2 mL/min at 25 ℃.The injection volume was 1 μL and detection wavelengths were set at 360 nm(λem) and 440 nm(λex) using fluorescence detector(FLD).The retention time was less than 5 min,and the whole analytical time was less than 45 min.The detection limits of AFB1,AFB2,AFG1,and AFG2 were 0.15,0.05,0.40 and 0.06 pg,respectively.The linear detection ranges of AFB1,AFB2,AFG1,and AFG2 were 0.4-60.0,0.2-15.0,1.5-60,0.2-15.00 pg with correlation coefficients(R2) of 0.9999,0.9999,0.9998,0.9992,respectively.Recovery rates in grains(corn,rice,wheat) spiked with aflatoxins were in the range of 77.4%-104.2%,with the relative standard deviation of 1.8%-8.9%.The method was suitable for the determination of aflatoxins in the raw grain,with the advantages of simplicity,rapidness,sensitivity,good reproducibility,and environment-friendly.