Determination of aflatoxins in domestic pet foods (dog and cat) using immunoaffinity column and HPLC

Abstract

A determination of aflatoxins in 35 samples of domestic pet foods (dog and cat) was carried out. A reversed phase HPLC method with fluorometric detection is described for the determination and quantification of aflatoxins B 1, B 2, G 1, G 2, M 1, M 2, P 1 and aflatoxicol after an immunoaffinity column clean up. The samples were drawn from 12 different commercially available pet foods in Mexico. The presence of seven aflatoxins and aflatoxicol was observed in most of the samples. Aflatoxin B 1 was the mycotoxin found with higher frequency (0.885) and was at high concentration in six samples (17.1%) of both dog and cat foods. Two of the samples contained a high concentration of total aflatoxins 72.4 and 59.7 ng/g. The total contamination of AFB 1 in cat food was higher in comparison to the dog food but statistical analysis using ANOVA one way and Dunnes test showed that there was no significant difference between cat and dog food samples, which was because of high standard deviation for the samples. Methods of analysis were tested by mean average recoveries of different aflatoxins and aflatoxicol spiked at levels of 0.5–8.0 ng/g ranged from 83–87% for AFG 1 and AFB 2 with relative standard deviation of <7% for AFP 1. Detection limits were 3–7 ng/g based on a signal-to-noise ratio of 4:1 at λ ex 370 nm/ λ em 418 nm. In conclusion, aflatoxin B 1 was present in most of the samples which even at low concentrations is of great concern for human and animal health. Maize was the main ingredient in all the contaminated samples.