Method for depletion or removal of endotoxin from an endotoxin-containing source or potentially endotoxin-containing source

A method for improved depletion or removal of endotoxins from a known or suspected endotoxin-containing source by virtue of a solid phase extraction material in an essentially aqueous system comprising the steps of

• providing a known or suspected endotoxin-containing source solution;
• contacting the known or suspected endotoxin-containing source solution with a positively charged solid phase material having a surface on which ferric iron is immobilized, wherein the solid phase material has immobilized the ferric iron by tris(2-aminoethyl)amine (TREN) ligand;
• incubating the known or suspected endotoxin-containing source solution for a period of time sufficient to bind endotoxin to the solid phase material and to form an incubated solution;
• and
• separating the solid phase material from the incubating solution to obtain a product solution with reduced endotoxin levels relative to the source solution, wherein the endotoxin levels are lower than endotoxin levels obtained by a process that is equivalent except for using iminodiacetic acid (IDA) chelating ligands.