Preconcentration and catalysis in reduction of aliphatic organohalides using surfactant-coated electrodes.

Voltammetric reductions of several organohalide pollutants in films of didodecyldimethylammonium bromide (DDAB) and clay-DDAB cast onto pyrolytic graphite electrodes were examined. Direct reduction data show that the amount of accumulation in these liquid crystal films was larger for relatively nonpolar analytes such as trans-1,2-dibromocyclohexane than for chlorinated acids. The vicinal dibromides are probably taken up by hydrophobic regions of the films. Chlorinated acids were accumulated and reduced in DDAB films, but their direct reduction was partly blocked by the clay-DDAB films. Catalytic reductions using films containing metal phthalocyanines had good efficiencies for all substrates studied and shifted reduction potentials positive by 200-550 mV.