THE EXTRACTION EQUILIBRIA OF THE ION ASSOCIATE OF PERIODATE WITH 1-(3,5-DIAMINO-6-CHLOROPYRAZINECARBOXYL) GUANIDINE

The extraction equilibrium of the ion-associate of periodate with 1-(3 ,5-diamino-6-chloropyrazinecarboxyl) guanidine hydrochloride (DPG(+)Cl (-)) was investigated spectrophotometrically. The optimum conditions f or the extraction of the ion associate DPG(+). IO4- with cyclohexanone have been established. The ion association constants, beta, K-D and K -ex and the molar absorpativity of the formed ion associate were deter mined. These values enable a convenient application of the investigate d system for the extraction spectrophotometric determination of period ate ions in the aqueous media. The molar ratio of the ion associate wa s found to be 1:1 of periodate to the reagent DPG(+)Cl(-) at pH 4-5. ( C) 1998 Elsevier Science B.V. All rights reserved.