DETERMINATION OF DDT (2,2-BIS (p-CHLOROPHENYL) 1,1,1-TRICHLOROETHANE) AND ITS METABOLITE IN BIOLOGICAL MATERIALS BY USE OF THE SCHECHTER-HALLER METHOD

¹ From the Division of Pharmacology, Food and Drug Administration, Federal Security Agency, Washington, D. C.

The colorimetric method of Schechter and Haller for DDT has been adapted to the determination of DDT and its known metabolite in biological materials. The method is fast and reliable down to 1.0 mg. per cent of either DDT or DDA in tissues or urine. Lower concentrations may be determined by the subtraction of an estimated blank with but a slight decrease in accuracy. The method is empirical and requires careful standardization of technic and reagents. An accuracy of 5 per cent can be obtained with DDT and 10 per cent with DDA. The standard deviation of duplicate analysis is ±0.5 micrograms for DDA and less for DDT.