|Kim, Eun kyung|
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/14/2003
Publication Date: 1/2/2004
Citation: Kim, E., Maragos, C.M., Kendra, D.F. 2004. Liquid chromatographic determination of fumonisin B1, B2 and B3 in corn silage. Journal of Agricultural and Food Chemistry. 52:196-200. Interpretive Summary: Corn silage is a popular feed source for dairy and beef cattle. Fumonisins, toxic substances produced by certain molds, are prevalent in field corn and potentially could remain intact in corn silage. Although a number of analytical methods for the determination of fumonisins in corn and other cereals have been developed, no chromatographic methods have been developed for silage, a notoriously difficult material to test. A sensitive, reproducible, and reliable analytical method to separate and quantify fumonisins from corn silage samples was developed and applied to samples collected from the Midwest during 2001-2002. Fumonisins were found in most of the samples, however the levels at which they were found were low enough that they are unlikely to affect cattle.
Technical Abstract: Corn silage is a popular feed source for growing ruminants. Several mycotoxins are known to exist in corn, raising the possibility they might survive ensiling and constitute a potential hazard to livestock. Fumonisins are a structurally related group of water soluble mycotoxins mainly produced by Fusarium verticillioides (formerly F. moniliforme) and Fusarium proliferatum, and frequently contaminate corn. A liquid chromatographic (LC) method for determining fumonisin B1, B2 and B3 in corn silage was developed. Corn silage was dried and then extracted with 0.1 M ethylenediaminetetraacetic acid (EDTA, tetra sodium salt), and the filtrate applied to a FumoniTest(TradeMark) immunoaffinity column. Fumonisins, eluted with methanol, were derivatized with naphthalene-2,3-dicarboxaldehyde (NDA), separated on a C18 LC column, and detected by fluorescence (excitation 268 nm, emission 470 nm). Under these conditions, retention times of fumonisins were 20.9 min for FB1, 40.7 min for FB3 and 43.3 min for FB2. The detection limits for FB1, FB2 and FB3 were 50, 25 and 25 ng/g of dried silage, respectively. Recoveries of FB1, FB2 and FB3 from wet and dried corn silage spiked over the range of 100-5000 ng/g averaged 91 to106 %. The method was applied to corn silage samples collected from the midwestern area of the United States during 2001-2002. Of 89 corn silage samples, FB1, FB2 and FB3 were found in 86 (97%), 64 (72%), and 51 (57%) of samples. The mean positive levels of FB1, FB2 and FB3 were 615 ng/g, 93 ng/g, and 51 ng/g, respectively in dried silage. This suggests fumonisins may be frequent low-level contaminants in corn silage.