INTERACTION OF IRON(II) WITH BILE-SALTS

Iron(II) ions react with small aggregates of cholate, glycocholate, ch enodeoxycholate, and deoxycholate to form soluble and colloidal compou nds. Taurocholate under conditions used does not react with the Fe2+ i on. Small aggregates of dihydroxy bile salts (predominating in the pre micellar region, at concentrations of the bile salt above 1 mmol dm(-3 )) have a larger affinity for Fe2+ compared to those formed from chola te anions. In their interactions with small aggregates of cholate anio ns, the Fe2+ ion shows an affinity comparable to that of Cu2+ and Cd2 and somewhat larger than that of Zn2+. Small aggregates of cholate sh ow a higher ability to mask Fe2+ than those of taurocholate and glycoc holate. Interaction of glycocholic acid anions with Fe2+ ions is suffi cient to prevent iron(II)precipitation.