High-performance liquid chromatographic method for the determination of di(2-ethylhexyl) phthalate in total parenteral nutrition and in plasma

A simple, rapid and sensitive reversed-phase high-performance liquid chroma tographic method with UV detection was developed for the quantification of di(2-ethylhexyl) phthalate (DEHP) in parenteral nutrition admixtures contai ning fat emulsion and in plasma samples of children daily treated by total parenteral nutrition. The analyte and the internal standard, di-n-heptyl ph thalate, were extracted twice using hexane and the organic layer separated and dried under nitrogen. The residues were reconstituted with acetonitrile and 20 mul was injected into a Waters Spherisorb C-18 column, the UV detec tor was set at 202 nm. The mobile phase was acetonitrile-aqueous buffer (tr iethylamine 0.08% adjusted to pH 2.8 with 1 M phosphoric acid) mixture (88: 12, v/v) and it was pumped at 1 ml/min. Average recoveries were 97% or grea ter. This method was successfully used to investigate the amounts of DEHP w hich can leach from bags and tubing into fat emulsion and which could conta minate children under long-term parenteral nutrition. On the other hand, th e circulating DEHP concentrations were estimated in four children under reg ular long-term, parenteral nutrition. (C) 2001 Elsevier Science B.V. All ri ghts reserved.