a microcolumn of alumina , activated at 250 degrees c over night and deactivated with 2 % water in an oven at 150 degrees c , has shown better separation characteristics than similar ones , deactivated at room temperature , for a great number of organochlorine compounds , particularly with respect to multicomponent toxaphene and pcb .
C0020247
organochlorine compounds
C0040521
toxaphene