title: Optimization and validation of a minicolumn method for determining aflatoxins in copra meal.
abstract: A minicolumn (MC) method for determining aflatoxins in copra meal was optimized and validated. The method uses methanol-4% KCl solution as extractant and CuSO4 solution as clarifying agent. The chloroform extract is applied to an MC that incorporates "lahar," an indigenous material, as substitute for silica gel. The "lahar"-containing MC produces a more distinct and intense blue fluoresence on the Florisil layer than an earlier MC. The method has a detection limit of 15 micrograms total aflatoxins/kg sample. Confirmatory tests using 50% H2SO4 and trifluoroacetic acid in benzene with 25% HNO3 showed that copra meal samples contained aflatoxins and no interfering agents. The MC responses of the copra meal samples were in good agreement with their behavior in thin-layer chromatography. This modified MC method is accurate, giving linearity-valid results; rapid, being done in 15 min; economical, using low-volume reagents; relatively safe, having low-exposure risk of analysts to chemicals; and simple, making its field application feasible.
authors.affiliation: Food and Nutrition Research Institute, Department of Science and Technology, Tagig, Metro Manila, Philippines.
authors.forename: R H
authors.initials: RH
authors.lastname: Arim
authors.forename: A R
authors.initials: AR
authors.lastname: Aguinaldo
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.forename: T
authors.initials: T
authors.lastname: Yoshizawa
mesh_terms: D000348:Aflatoxins / Q000032:analysis*; D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D002417:Cattle; D002845:Chromatography / Q000379:methods*; D002855:Chromatography, Thin Layer; D003059:Cocos; D019327:Copper Sulfate; D000432:Methanol; D010679:Philippines; D011189:Potassium Chloride; D012996:Solutions
chemical_list: D000348:Aflatoxins; D012996:Solutions; D011189:Potassium Chloride; D019327:Copper Sulfate; D000432:Methanol