biophys 134 279 284 with caprylic acid and by adding caprylic acid it can also take place through precipitation agents such as rivanol aluminum chloride cetylpyridinium chloride octanoic acid polyphosphates and in presence of adsorption agents with tricalcium phosphate and bentonite the supernatant can constitute the concentrate of immunoglobulins according to the invention it therefore contains a mixture of igg a and m this is recovered for example by centrifugation or filtration optionally by adding at least one filtration additive the supernatant can undergo conventional viral deactivation processing with a solvent detergent triton x100 if the precipitation was a caprylic precipitation the residues of caprylic acid in the supernatant are eliminated by po4 calcium in order to obtain a concentrate of igg iga or igm the method described in the application ep02727688 0 can be applied the supernatant then undergoes an additional step of purification by chromatography on an anion exchanger performed in alkaline ph in particular the ph of the supernatant is adjusted beforehand to a ph between 8 9 and 9 1 and the column is loaded with a buffer at a ph 8 9 to 9 1 the chromatography step allows the adsorption of immunoglobulins and passage of non retained proteins into the effluent chromatography can be performed on a reticulated polysaccharide or vinyl polymer gel grafted with deae tmae or qae groups after washing the column with the same buffer as the loading buffer to eliminate non retained proteins immunoglobulins g are eluted with a phosphate buffer the ph of which is between 4 and 7 preferably at ph 6 2 an optional subsequent elution with the same phosphate buffer supplemented with 100 to 175 mm nacl preferably 150.