Voltammetric Identification of Organochlorine Insecticides, Polychlorinated Biphenyls, Polychlorinated Naphthalenes and Polychorinated Benzenes
Farwell, SO; Beland, FA; Geer, RD
A method for the voltammetric reduction of polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) was evaluated. An apparatus was used that employed three electrode potentiostatic control circuitry with an interruptible linear voltage sweep control. Voltage scan rate was 142 milliVolts per second (mV/sec). Symmetric and asymmetric PCBs were prepared and confirmed. Molar concentrations of solutions used contained 0.0005 moles (M) of the electroactive species. Dimethyl-sulfoxide (67685) was used as the solvent with 0.1M tetraethylammonium-bromide (71910). Hexachlorobenzene (118741), DDE (72559), and 2,4,5,2',4',5'-hexachloro-biphenyl (35065271) were identified by comparison of their voltammetric readings with those of known compounds. Interruption voltages (E2d) values were used to aid identification and were varied by as much as 20mV; however, since each reduction peak shifted by the same amount, the relative difference remained constant. The detector required relatively pure compounds for positive identification. Also identified were polychlorinated benzenes, and heptachlor (76448), dieldrin (60571), aldrin (309002), lindane (58899), chlordane (12789036), and trans-chlordane (5103742), which represented some of the more than 100 organochlorine compounds that were analyzed.