Carboxymethyl dextran-iron complexes

Claim 1

A METHOD FOR MAKING CARBOXYALKYL DEXTRAN-IRON COMPLEXES WHICH ARE ACID-SOLUBLE AND ALKALI-PRECIPITABLE, COMPRISING ADDING AN AQUEOUS SOLUTION OF A WATER-SOLUBLE IRON SALT TO AN AQUEOUS SOLUTION OF A CARBOXYALKYL ETHER OF INHERENTLY WATER-DISPERSIBLE DEXTRAN CONTAINING, PER ANHYDROGLUCOSE UNIT, AN AVERAGE OF ABOUT 1.0 TO 3.0 CARBOXYALKYL GROUPS THE ALKYL PORTION OF WHICH CONTAINS FROM ONE TO FOUR CARBON ATOMS, HOLDING THE MIXTURE AT ACID PH UNTIL THE COMPLEX IS FORMED, ADDING AQUEOUS ALKALI TO THE MASS UNTIL THE PH THEREOF IS RAISED TO A VALUE AT WHICH THE COMPLEX FORMED, IS AT STABLE AND DOES NOT TEND TO RE-DISSOLVE IN THE FLUID REACTION MASS, AND THEN PRECIPITATING THE COMPLEX FROM THE FLUID REACTION MASS BY ADDING TO THE LATTER A WATER-MISCIBLE, NON-POLAR SOLVENT PRECIPITANT FOR THE COMPLEX, AND SEPARATING THE COMPLEX.

Claim 2

A METHOD FOR MAKING CARBOXYALKYL DEXTRAN-IRON COMPLEXES WHICH ARE ACID-SOLUBLE AND ALKALI-PRECIPITABLE, COMPRISING ADDING AN AQUEOUS SOLUTION OF A WATER-SOLUBLE IRON SALT TO AN AQUEOUS SOLUTION OF A CARBOXYALKYL ETHER OF INHERENTLY WATER-DISPERSIBLE DEXTRAN CONTAINING, PER ANHYDROGLUCOSE UNIT, AN AVERAGE OF ABOUT 1.0 TO 3.0 CARBOXYALKYL GROUPS THE ALKYL PORTION OF WHICH CONTAINS FROM ONE TO FOUR CARBON ATOMS, HOLDING THE MIXTURE AT ACID PH UNTIL THE COMPLEX IS FORMED, ADDING AQUEOUS ALKALI TO THE MASS UNTIL THE PH THEREOF IS RAISED TO A VALUE AT WHICH THE COMPLEX FORMED, IS AT STABLE AND DOES NOT TEND TO RE-DISSOLVE IN THE FLUID REACTION MASS, AND THEN PRECIPITATING THE COMPLEX FROM THE FLUID REACTION MASS BY ADDING TO THE LATTER A WATER-MISCIBLE, NON-POLAR SOLVENT PRECIPITANT FOR THE COMPLEX, AND SEPARATING THE COMPLEX.