TABLE OF CONTENTS The procedure described next is based on cathode-ray polarography of a solution of the extractant in 0.02 M aqueous tetramethyl ammonium iodide (TMAI). Polarographic cell solutions were prepared by mixing 1 ml of 0.2 M aqueous TMAI base electrolyte base to the distilled water extractant. The results obtained by polarography of 0.02 M aqueous base-electolyte solutions (start potential of 1.8 volts) showed that it is possible with either the cathodic direct or the cathodic derivative circuits to determine down to 1 ppm of acrylonitrile monomer in the distilled water extractant. Confirming the conclusions of Bird and Hale [1] and Daues and Hamner [2] it was found that the presence in the cell solution of dissolved oxygen did not interfere in the polarographic determination of acrylonitrile in the range 1.8 to 2.3 volts.
Liquids obtained in extractability tests on styrene-acrylonitrile copolymers also usually contain a small amount of styrene monomer besides acrylonitrile monomer. It has been shown that the presence of up to 500 ppm of styrene monomer in the test solution does not interfere in the determination of acrylonitrile in aqueous solutions.
To 9 ml of each ethanol-water mixture containing 50 ppm of added acrylonitrile was added 1 ml of 0.2 M TMAI base-electrolyte solution. Reagent blank solutions were also prepared by mixing 9 ml of the appropriate acrylonitrile free ethanol-water mixture with 1 ml of 0.2 M base electrolyte. These samples...
