Competitive solid phase enzyme-linked immunoassay for the quantification of limonin in citrus

A solid-phase enzyme immunoassay for the quantitative determination of the bitter triterpene-lactone, limonin, in citrus juice samples is described. As little as 0.1 ppm of limonin can be detected. Quantitative results are available within 1 h of total assay time. The assay makes use of a limonin-alkaline phosphatase tracer of high immunoreactivity and has been semiautomated using antibody-coated polystyrene microcuvettes, a vertical light path photometer, and a forced-air microplate incubator.