University of North Florida
Browse the Citations

Contact Info

Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Website: @unf

View Stuart Chalk's profile on LinkedIn


Classification: Agricultural -> grain -> tapioca

Citations 1

"Fluorimetric Determination Of Aflatoxins By Flow Injection Analysis"
Fresenius J. Anal. Chem. 1988 Volume 332, Issue 7 Pages 809-812
Fernando Lazaro, M. Dolores Luque de Castro and Miguel Valcarcel

Abstract: Peanuts (100 g) are extracted by shaking with 500 mL of aqueous 55% methanol plus 200 mL of hexane and 4 g of NaCl. A 25 mL portion of the aqueous methanol phase is extracted with 25 mL of CHCl3, the CHCl3 is evaporated under N, and the residue is dissolved in 5 mL of methanol. The solution is diluted to 10 mL with water, filtered through nylon 66 (0.45 µm) and extracted with 10 mL of CHCl3. The extract is evaporated, the residue is dissolved in 1 mL of methanol, and the solution is diluted to 5 mL with water. Maize or tapioca (50 g) is mixed with 10 g of diatomaceous earth and extracted with 150 mL of aqueous 85% acetone, the mixture is filtered, and 50 mL of the filtrate is mixed with 20 mL of saturated (NH4)2SO4 solution, 130 mL of water and 10 g of diatomaceous earth. This mixture is filtered, and 100 mL of the filtrate is extracted with 3 mL of benzene. The extract is evaporated under N, the residue is dissolved in methanol and the solution diluted with water as before. Each sample solution was injected into a stream of aqueous 40 µM-Br, and the fluorescence was monitored at 470 nm. From 0.5 to 200 ng mL-1 of total aflatoxins (B1, B2, G1 and G2) could be determined. The method is very rapid, the residence time for each flow injection peak being only 6 s.
Aflatoxins Fluorescence