James E. Hutchins

Evaluation of silica cartridge purification and hemiacetal formation for liquid chromatographic determination of aflatoxins in corn

Rapid silica cartridge cleanup, acid-catalyzed conversion of aflatoxins B1 and G1 to hemiacetals, and reverse-phase liquid chromatography with fluorescence detection were evaluated for effectiveness in determining aflatoxins B1, B2, G1, and G2 in corn at concentrations ranging from 2 ng/g to 100 (μg/g. In testing the method, aflatoxins applied to silica cartridges were recovered at greater than 97.1% overall. Conversion of aflatoxins B1 and G1 to their hemiacetals was shown to be complete (150 μg of toxin per extract). Application of these techniques to spiked corn extracts yielded data indicating excellent repeatability of derivatization relative to paired standards; coefficients of variation ranged from 1.08% to 5.81%. The repeatability of the method with naturally contaminated corn was also excellent; coefficients of variation ranged from 1.15% to 3.97%. Liquid Chromatographic determination of aflatoxins in corn using fluorescence detection was sensitive, accurate, and precise resulting in applicability from <1 ng/g of aflatoxin B1 to > 100,000 ng/g.

Purification of adenovirus hexon by high performance liquid chromatography

Hexon is the major structural protein of adenovirus, and has significance in studies of virus structure and function, vaccine development, and immunodiagnosis. We describe a simple, single-step, anion-exchange high performance liquid chromatography (HPLC) method for the high yield purification of hexon. Purity of the isolated hexon was assessed by SDS-PAGE and HPLC methods. The isolated hexon was immunologically reactive with anti-hexon monoclonal antibody in a dot-blot assay. It also retained immunogenicity, as polyclonal antisera from rabbits immunized with hexon showed the desired antigen specificity. The enhanced speed of this purification method allows for the efficient isolation of hexon from various serotypes, and thus may facilitate comparative studies of hexon immunobiology.