Complete dechlorination of DDT and its metabolites in an alcohol mixture using NaOH and Pd/C catalyst.
DDT (1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane) was dechlorinated in 2-propanol/methanol (99:1v/v) by means of stoichiometric reaction with NaOH and subsequent catalytic dechlorination over Pd/C catalyst. When DDT was treated with a molar excess of NaOH ([NaOH]/[DDT]=9) in the alcohol mixture at room temperature, DDT disappeared within 15min. The reaction of DDT produced an equimolar amount of HCl to yield DDE (1,1-bis(4-chlorophenyl)-2,2-dichloroethylene). The produced DDE was successfully dechlorinated to a chlorine-free product (1,1-diphenylethane, 97% yield) by addition of Pd/C to the alkaline solution and heating at 40 degrees C for 4h. DDD (1,1-bis(4-chlorophenyl)-2,2-dichloroethane) was also dechlorinated to 1,1-diphenylethane in a similar manner. Possible dechlorination pathways for DDT, DDE, and DDD were investigated by observation of the partially dechlorinated intermediates by means of gas chromatography/mass spectrometry (GC/MS).
Ukisu
Yuji
Y
National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba West, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan. y-ukisu@aist.go.jp
D000438:Alcohols / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D002713:Chlorine / Q000737:chemistry*; D003634:DDT / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D010165:Palladium / Q000737:chemistry*; D012972:Sodium Hydroxide / Q000737:chemistry*
D000438:Alcohols; D002713:Chlorine; D012972:Sodium Hydroxide; D010165:Palladium; D002244:Carbon; D003634:DDT