Otimização de método analítico para determinação de aflatoxinas em rações de caprinos e ocorrência no estado da Bahia Optimization of analytical method for aflatoxins determination in goats feedstuffs and their occurrence in the state of Bahia

<abstract language="eng">The optimization of the thin layer chromatography (TLC) method to determine aflatoxins in feedstuffs and the evaluation of their occurrence in feedstuffs for milk-yielding does in the state of Bahia were studied. Eighty feedstuff samples were collected from five farms, located in the Recôncavo Baiano, from November 2000 to August 2002. The samples were analyzed using TLC modified method. In this study, the detection and quantification limits were 5 and 8m g/kg, respectively. The percentage of average recoveries obtained for AFB1, AFB2, AFG1, and AFG2 were 81.0; 97.2; 89.3; and 90.3%, respectively; and the coefficient of variation ranged from 0.83 to 4.1%. The results revealed that the optimization of TLC methodology is efficient to analyze aflatoxins in feedstuffs. The presence of these aflatoxins was not detected in any of the analyzed samples, demonstrating good quality of those products, regarding the contamination by these toxins.