A new metabolite was purified from chloroform extracts of Claviceps paspali sclerotia by using column chromatography and preparative centrifugally accelerated, radial, thin-layer chromatography. The chemical structure of the metabolite was determined by ¹H and ¹³C NMR spectroscopy to be 4-(3-methyl-2-butenyl)paspalinine (paspalitrem C). Paspalitrem C differed from the previously identified tremorgen, paspalitrem A, only by the position of attachment of the 3-methyl-2-butenyl unit to the indole ring. A method for the determination of aflatoxins B₁ and M₁ in small samples (1 g) of beef liver, using a simple and rapid extraction and cleanup procedure, has been developed. C₁₈ disposable columns are used in conjunction with normal-phase high-performance liquid chromatography with a packed-cell fluorescence detector. The method is particularly suitable for the analysis of small autopsy and biopsy specimens, which are not amenable to analysis by published methods due to sample size limitations. Recoveries from liver samples fortified at the 0.5-ppb level were 96% for aflatoxin B₁ and 58% for aflatoxin M₁.