1. W. J. Blaedel and R. A. Jenkins, Anal. Chem. 48, 1240 (1976).
2. W. J. Blaedel and R. C. Engstrom, Anal. Chem. 52, 1691 (1980).
3. A. Malinauskas and J. Kulys, Anal. Chim. Acta, 98, 31 (1978).
4. J. J. Kulys and G-J. S. Svirmickas, Anal. Chim. Acta, 117,115 (1980).
5. K. Nakamura, S. Nankai and T. Iizima, Astracts of Papers, 46th Annual Meeting of the Electrochemical Society of Japan, 1979, p. 71.