A separation and purification procedure for [14C] di-2-ethylhexyl phthalate in fish

A procedure utilizing the reverse isotope dilution analysis is presented for the determination of di-2-ethylhexyl phthalate (DEHP) and total metabolites in tissues of fish and water samples. This procedure offers several advantages: it eliminates laborious and expensive use of column chromatography and identification by gas chromatography/mass spectrometry analysis; it does not require quantitative separation; it selectively removes fish lipids by partitioning across a hexane/acetonitrile system; it uses an internal standard, di-pentylphthalate, for the gas-liquid chromatographic analysis; and it overcomes interference from background DEHP.