Comparison of three methods for determining aflatoxins in melon seeds.

The suitability of 3 methods for determining aflatoxins in melon seeds was examined. The first 2 are the Contaminants Branch (CB) method and the Best Foods (BF) method, both official methods for determining aflatoxins in peanuts and peanut products. The third method, the modified CB method-Rapid Modification of the Cottonseed (CB-RCS-Mod) method, devised in this work, was derived by combining steps from the CB method and the Rapid Modification of the Cottonseed method.

Negative ion chemical ionization mass spectrometric method for confirmation of identity of aflatoxin B1: collaborative study.

An interlaboratory study of a negative ion chemical ionization mass spectrometric (MS) confirmation procedure for aflatoxin B1 was conducted in laboratories in the United States, England, and West Germany. Twelve partially purified, dry film extracts from naturally and artificially contaminated roasted peanuts, cottonseed, and ginger root containing varying quantities of aflatoxin B1 were distributed to the participating laboratories. The extracts required additional cleanup before MS analysis, using either an acidic alumina column and preparative thin layer chromatography (TLC) or a 2-dimensional TLC procedure.

Minicolumn detection method applied to almonds: collaborative study.

The minicolumn screening method for aflatoxins was collaboratively tested on naturally contaminated almonds. The nuts were extracted, and the extract was cleaned up and applied to a Velasco-type minicolumn. This permits the detection of total aflatoxins (B1, B2, G1, G2) as a fluorescent band on the Florisil layer of the column.

Distribution of aflatoxins in some samples of peanuts.

Naturally occurring G aflatoxins were found at approximately 20 times the level of B aflatoxins in one lot of roasted, blanched peanuts. Official methods, as well as high-pressure liquid chromatography, were used to confirm this finding. Additional routine sample analysis data of raw and roasted peanuts revealed that this finding is not so unusual formerly thought.