EFFECTS OF ACETONE, ETHANOL, ISOPROPANOL AND DIMETHYL-SULFOXIDE ON AMYLOSE-IODINE COMPLEX (VOL A35, PG 711, 1998)

The amylose-iodine (AI) complex formation was studied by absorption sp ectra in water and water containing varying proportions of ethanol, ac etone, isopropanol and dimethyl sulfoxide (DMSO). Complex formation is most favored in pure water and decreases as the proportion of nonaque ous solvent is increased. A decrease in the absorbance intensity at ar ound 615 nm (for Al complex) is accompanied by a peak shift towards 55 0 nm and an increased absorbance at around 350 nm (for unbound iodine) . The amount of the nonaqueous solvent added, as well as the order in which it is added relative to amylose and iodine solution, change rema rkably the extent of the AI complex formation. A mechanism of the comp lex formation is proposed.