Replacement of benzene as a solvent for aflatoxin standards

Cyclohexane, heptane and toluene were evaluated for possible replacement of benzene in the preparation of aflatoxin standard solutions. The results of a 6‐month study showed that these solvents can be substituted for benzene, provided they are not unduly exposed to light. The superiority of benzene as a solvent for aflatoxin standards was clearly demonstrated in a test in which these solvent systems containing 5 μ g B 1 /mL, were exposed to daily lighting in the laboratory for 3 months. Complete photodegradation of aflatoxin B 1 occurred in the cyclohexane, heptane and toluene systems whereas only a 15% B 1 decrease occurred in the benzene system.