Estimation of o,p'-DDD in plasma by gas-liquid chromatography

A method is described for the estimation of o,p'-DDD in plasma. To 50 microl plasma, 0.2 ml acetone is added. The mixture is extracted with 2 ml n-heptane containing p,p'-DDD as an internal standard. Water is removed by adding desiccated sodium sulfate. The organic phase can be injected into a gas chromatograph equipped with an electron capture detector. The o,p'-DDD content of the sample can be read from a calibration curve. Recovery of o,p'-DDD added to plasma is over 93%. The same procedure can be used for the estimation of o,p'-DDE.