|Kim, Eun Kyung|
|Scott, Peter - HEALTH CANADA|
|Lau, Ben P-Y - HEALTH CANADA|
Submitted to: Association Official Analytical Chemists Annual Intrl Meeting & Exposition
Publication Type: Abstract Only
Publication Acceptance Date: September 26, 2002
Publication Date: September 26, 2002
Technical Abstract: Retail corn flakes (twenty five samples from 15 lots) were analyzed for fumonisin B1 (FB1) and fumonisin B2 (FB2), which were detected in 22 and 12 samples, respectively, at mean concentrations of 68 and 8 ng/g. Methanol-acetonitrile-water (25:25:50) was used for extraction and C18 or immunoaffinity column (IAC) for clean-up; there was an excellent correlation between FB1 results obtained with the two clean-up procedures. The corn flakes residue was extracted with 1% sodium dodecyl sulphate (SDS) solution which was hydrolyzed with 2N potassium hydroxide. Matrix-bound fumonisin was determined as HFB1, which was found in residues from all the corn flakes samples, even those containing no detectable FB1. The mean concentration of HFB1 formed was 101 ng/g, equivalent to 180 ng FB1/g. Thus an average of 2.6 times more FB1 was present in bound form compared to the average concentration found by conventional analysis. Concentrations of HFB1 ranged from 43 ng/g (from a sample with only 12-15 ng/g FB1/g) to 288 ng/g (from a sample containing 82-86 ng FB1/g). There was a logarithmic relationship between the FB1 (C18 clean-up) and HFB1 concentrations (r=-0.5034). This low degree of correlation should be taken into account by food safety authorities when estimating human exposure to protein-bound fumonisin.