Determination of aflatoxins in grains and raw peanuts by a rapid procedure with fluorometric analysis.
A rapid, quantitative, inexpensive, and efficient method was developed to determine aflatoxins in corn, corn meal, popcorn, rice, wheat, cottonseed, and peanuts. Samples are ground and extracted with methanol-water (80 + 20). A portion of the extract is cleaned up by passage through a solid-phase separatory column, 500 microL purified extract is derivatized with a bromine reagent, and fluorescence of the solution is immediately quantified with a calibrated fluorometer containing a broad wavelength pulsed xenon light source. This method can quantify aflatoxin from 5 to 5000 ppb without dilution and was linear when applied to samples of noncontaminated corn spiked at 0 to 5000 micrograms aflatoxin B1/g. Correlation coefficients of the method with LC for multiple analyses for corn (n = 34), cottonseed (n = 32), and peanuts (n = 11) were 0.999, 0.995, and 0.980, respectively. Individual analyses may be conducted in less than 5 min, and grouping of samples is unnecessary. The sensitivity of the method for corn is 5 ppb and the fluorometer, under the operating conditions, has a limit of detection of 0.6 ng aflatoxin B1.
Malone
B R
BR
Romer Labs, Inc., Union, MO 63084-1156, USA.
Humphrey
C W
CW
Romer
T R
TR
Richard
J L
JL
D016604:Aflatoxin B1 / Q000032:analysis; D000348:Aflatoxins / Q000032:analysis*; D010367:Arachis / Q000737:chemistry*; D001966:Bromine; D002853:Chromatography, Liquid / Q000379:methods*; D003369:Cottonseed Oil / Q000737:chemistry; D002523:Edible Grain / Q000737:chemistry*; D007202:Indicators and Reagents; D012275:Oryza / Q000737:chemistry; D011786:Quality Control; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence; D014908:Triticum / Q000737:chemistry; D003313:Zea mays / Q000737:chemistry
D000348:Aflatoxins; D003369:Cottonseed Oil; D007202:Indicators and Reagents; D016604:Aflatoxin B1; D001966:Bromine