From 16 attempts to concentrate tetanic antitoxin by adsorption on commercial kaolin and subsequent elution, the following statements may be made.
The potency of tetanic antitoxin was not altered after storage at room temperature for an 8-day period at hydrogen ion concentrations varying from pH 3.8 to 9.4.
Adsorption by kaolin at pH 3.8 proceeded regularly and the antitoxic potency of the serum was reduced by about 80 per cent.
Adsorption was not selective; all of the proteins were adsorbed at the same time.
The antitoxin could be separated from the other proteins by the Fodor method at pH 9.3–9.4. This separation, however, did not proceed regularly, and the yields were very variable. In the most successful experiment the percentage yield of antitoxin was 56, and the increase in antitoxic potency was 114 times as calculated on the basis of nitrogen determinations.
For the present, at least, methods of adsorption and elution are not suited to the commercial concentration of tetanic antitoxin.
Presented before the Physico-Chemical Section of the Third South American Congress for Chemistry, at Rio de Janeiro, Brazil, July, 1937.