Although 50 countries have enacted or proposed regulations for control of alfatoxins in food or feed, and 15 of these countries also have regulations for permitted levels of contamination by other mycotoxins, very few countries have formally presented the rationale for the need to regulate, or for the selection of a particular maximum tolerated level. After several successive inquiries, information concerning the rationale for regulation was obtained from 21 countries. Most of the responses concerned limits for aflatoxin in food, and most of these were based on a vague, unsupported statement of the carcinogenic risk for humans. There was a general consensus that exposure to a potential human carcinogen that could not be totally avoided should be limited to the lowest practical level; the definition of practicality depended on whether the country was an importer or producer of the potentially contaminated commodity. A claim to a hazard evaluation was made by six countries (Canada, Belgium, India, United Kingdom, United States, Switzerland) without providing specifics; and one country, South Africa, referred to a risk determination. The most comprehensive rationale for any mycotoxin regulation was provided by the United States in support of limits for aflatoxin in specific animal feedstuffs. The responses provided no rationale for setting limits for other mycotoxins; but scholarly risk assessments for zearalenone and ochratoxin A have been published by Canadian government scientists, and a symposium presentation provides the information that in Norway patulin is regulated for quality control purposes only. It is apparent that, in most countries, either the scientific basis for regulation of mycotoxins is nonexistent, or the science has not been fully utilized.(ABSTRACT TRUNCATED AT 250 WORDS)

Aflatoxins↗

PubMedDate not supplied

Determination of aflatoxicol and aflatoxins B1 and M1 in eggs.

Procedures from 2 methods, one for aflatoxins B1 and M1 in eggs and one for aflatoxicol in milk, blood, and liver, have been combined to determine the 3 toxins in eggs. The sample is blended with sodium chloride-saturated water and this mixture is then blended with acetone. After separation from the solid residue, the aqueous acetone extract is defatted with petroleum ether. The toxins are next partitioned into chloroform and separated from interferences on a silica gel column. Aflatoxicol is determined by fluorescence measurement after separation on a C18 reverse phase liquid chromatographic column, and aflatoxins B1 and M1 are determined by fluorescence densitometry after separation on a silica gel thin layer chromatographic plate. In a recovery study with eggs, mean recoveries of aflatoxicol added at levels of 0.1, 0.05, and 0.025 ng/g were 87, 77, and 78%, respectively. Mean recoveries of aflatoxins B1 and M1 added at a level of 0.1 ng/g were 75 and 87%, respectively, and at an added level of 0.05 ng/g were 86 and 75%. The within-laboratory precision (repeatability) ranged from 2 to 13%.

Aflatoxin B1↗

PubMedDate not supplied

Determination of aflatoxins in peanut butter, using two liquid chromatographic methods: collaborative study.

Two methods for determining aflatoxins in peanut butter, one using normal phase and the other reverse phase liquid chromatography (LC), were studied by 8 and 10 collaborators, respectively. Fluorescence detection was used for the determinative step in both methods. For reverse phase LC, aflatoxins B1 and G1 were converted to B2a and G2a; for normal phase LC, a silica gel-packed flow cell was placed in the irradiating light path of the detector. The samples included spiked and naturally contaminated peanut butter with total aflatoxin levels from about 5 to 20 ng/g and controls in a balanced pair design. For the normal phase LC method, recoveries of B1, B2, G1, and G2 from spiked samples averaged 79, 92, 74, and 88%, respectively; for the reverse phase method, the recoveries were 103, 104, 89, and 163%. For the normal phase LC method, pooled repeatabilities were 20, 23, 28, and 17% for B1, B2, G1, and G2, respectively; for the reverse phase method, the repeatabilities were 19, 22, 38, and 31%. For the normal phase method, pooled reproducibilities were 34, 33, 39, and 34% for B1, B2, G1, and G2, respectively; for the reverse phase method, the reproducibilities were 32, 46, 51, and 52%. Both methods show an improved limit of detection and better within-laboratory precision over current AOAC methods; however, between-laboratory precision is no better, and the reverse phase method shows evidence of interferences being measured. For these reasons and because of no benefits of present value, neither method was submitted for adoption as official first action.

Aflatoxins↗