Determination of Aflatoxins and Ochratoxin a in Animal Liver using HPLC-FD Method with Immunoaffinity Column Clean-Up

Analytical methods based on immunoaffinity column clean-up and quantitative determination with liquid chromatography-fluorescence detection were used to determine aflatoxins and ochratoxin A in liver samples. The validation of the procedures was performed. The linearity of the methods was checked, and a good coefficient of correlation was found for all aflatoxins and OTA as well. The LOD and LOQ were acceptable: 0.003 µg/kg and 0.009 µg/kg for AFB₁; 0.001 µg/kg and 0.005 µg/kg for AFB₂; 0.006 µg/kg and 0.020 µg/kg for AFG₁; 0.007 µg/kg and 0.022 µg/kg for AFG₂; 0.08 µg/kg and 0.27 µg/kg for OTA. The results for the repeatability estimated by the relative standard deviation (RSD_r) were satisfactory and the obtained values were in the acceptable range (1.97–14.41% for all aflatoxins and 3.76-8.31% for OTA) at three proposed concentration levels. RSD_R values showed acceptable correlation between two analysts for all four aflatoxins and OTA. The RSD_R values were as followed: 2.37% and 5.60% for AFB1, 6.71% and 8.78% for AFB₂, 4.40% and 7.00% for AFG₁ and 10.30% and 13.91% for AFG₂ (for the first and second analyst, respectively). The RSDR values for OTA were 4.91% and 3.15% (1 µg/kg); 3.76% and 4.12% (5 µg/kg) and 8.31% and 8.21% (10 µg/kg). The mean recovery for total aflatoxins and OTA were 78.10% and 93.34%, respectively. All validation parameters were in accordance to European legislation. They indicate that the proposed analytical procedures are suitable and they could be methods of choice for the determination of aflatoxins and OTA in liver samples.