Submitted to: Aflatoxin Elimination Workshop Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 10/1/1999
Publication Date: N/A
Citation: Wauchope, R.D., Ho, A., Holbrook Jr, C.C., Haney, B., Hassapis, C., Mubatanhema, W., Wilson, D. 1999. Rapid and sensitive analytical methods for aflatoxins: an update.. Aflatoxin Elimination Workshop Proceedings. Oct. 20-22, 1999, Atlanta, GA. Interpretive Summary:
Technical Abstract: FILIA (flow-injection liposomal immunoassay) appears to be a good candidate technique for rapid, portable and inexpensive analysis of aflatoxins. Liposomes were successfully "tagged with aflatoxin B1; however, aflatoxin B1 is so hydrophobic it disrupted liposome formation. This problem has been solved by using a longer "bridge" molecule. A miniaturized, automated dprocedure called MFILIA is being developed by Saddleback Aerospace under a USDA Small Business Innovation Grant -- see http://www.saddle-aero.com/ minchem.htm. Using the tagged liposomes from the FILIA experiment, it is possible to develop a simple "dip-stick" procedure in which plastic-backed nitrocellulose paper strips behave just like the columns, but the dye is simply released in place and the intensity read by eye (or densitometer for more quantitative results). Our first test gave a useful range from about 10 to 10,000 ppb aflatoxin B1. Standing SPE (solid phase extraction) columns gave comparable results to immunosorbent columns as an isolation technique prior to HPLC analysis. In addition, pesticides sorbed on SPE disks have been shown to be quite stable, and, once dry, such disks can be sent via regular mail to distant laboratories for analysis. SPE columns with adsorbed aflatoxins were spiked with standard aflatoxins and shipped from Blue Diamond Growers' Labs in Sacramento to Tifton and analyzed with 80% or better recoveries on arrival. This suggests a convenient and inexpensive way to preserve and ship aflatoxin samples for remote analysis.