Submitted to: Aflatoxin Workshop
Publication Type: Abstract Only
Publication Acceptance Date: October 27, 2000
Publication Date: N/A
Technical Abstract: A rapid, portable, immunoassay method was developed for fumonisins in maize using the principle of fluorescence polarization (FP). An advantage of FP over other forms of immunoassays is that the polarization is independent of intensity and concentration and the assays can be conducted with colored or cloudy solutions. The FP assays were also simple, requiring only the mixing of a sample extract with antibody and tracer and measurement. Samples of maize spiked with fumonisin B1 (FB1) were extracted with phosphate buffered saline (PBS). Extracts were then tested using two different FP protocols in order to gauge the impact of matrix effects upon the assay response. The protocols differed both in how the samples were handled and in what procedures were used to compile the data. Recoveries of FB1 from spiked maize over the range of 0.5 to 20 ppm averaged 94%. Naturally contaminated maize samples were analyzed by both FP protocols and by a widely used HPLC method. A comparison with 48 naturally contaminated samples indicated a good correlation between the HPLC method and the first FP protocol (r2=0.85), a good correlation between the HPLC method and the second FP protocol (r2=0.88), and an excellent correlation between the two FP protocols (r2=0.97). The two FP protocols were performed by different personnel in different laboratories and the good agreement between them suggests the FP technology may be very robust. These results, combined with the speed and ease of use of the assays, suggest that this technology has substantial potential as a screening tool for fumonisins in foods.