Solid-phase microextraction and gas chromatography-mass spectrometry analysis of p,p' -DDE in biological samples

A simple and rapid extraction method for the analysis of p,p'-DDE from rat whole blood and tissues was developed using headspace solid-phase microextraction (SPME). A vial containing a sample of p,p'-DDE, sodium hydroxide, and benzophenone as internal standard was heated at 120 degrees C. A polydimethylsiloxane-coated SPME fiber was exposed for 15 min in the headspace of the vial. The fiber needle was then injected and desorbed by exposing the fiber in the injection port of a capillary gas chromatography-mass spectrometry system. The calibration curve demonstrated good linearity throughout the concentration range from 0.02 to 50 microg/g for rat whole blood and liver samples. The limit of detection for p,p'-DDE was 0.020 microg/g using 0.5 g rat whole blood and liver samples. Coefficients of variation ranged from 7.0 to 7.9%. This method was used to analyze a rat whole blood sample after administration of p,p'-DDE.