“…Other solvent systems that have been used for these purposes are n-butanol-acetic acid-water (12:3:5) and n-butanol-acetic acid-water-isopropanol (8:2:5:3) (Michaelis, 1977). Heim et al, 1966b;Høiland , 1978;Hatfield and Valdes, 1978;White, 1979;Beug and Bigwood, 1981;Gartz, 1985c n-Butanol-acetic acid-water (2:1:1) Stamets et al, 1980;Bigwood, 1981, 1982;Stijve et al, 1984, Marcano et al, 1994 n-Butanol-acetic acid-water (24:10:10) SG 0.19 0.50-0.54 n.r. Picker and Rickards, 1970;Wurst et al, 1984;Semerdžieva et al, 1986;Wurst et al, 1992. n-Butanol-acetic acid-isopropanol-water 0.22 Leslie, 1977a, 1977b;Repke et al, 1977, Hatfield andValdes, 1978;Koike et al, 1981 n-Propanol-6% ammonia n.r.…”