Chromatographical Determination of Radiochemical Purity of Hippuran $^131 I$

A recently known method of paper chromatographical separation of o-iodobenzoic acid-$^{131}$ I and o-iodohippuric acid-$^{131}$ I was found to be in error. The solvent mixture proposed in the method for the efficient separation of the two compounds of similar structure not only be made nonhomogeneous but also brings about no separation. It was also confirmed that no o-iodohippuric acid is converted to o-iodobenzoic acid during the process for Hippuran -$^{131}$ I preparation by isotopic exchange. Upon it, an alternate method of chromato-graphical determination of radiochemical purity of Hippuran-$^{131}$ I is proposed in present paper.

페이퍼 크로마토그래피에 의한 o-iodohippuric acid-$^{131}$ I와 o-iodobenzoic acid-$^{131}$ I의 분리에 관한 기보된 방법은 착오인 것으로 밝혀졌다. 이들 두 유사 화합물들의 효과적 분리를 위하여 제시된 용매는 균일하게 섞여지지 않을뿐 아니라 그대로 사용하더라도 이들 두 화합물은 분리되지 않았다. o-iodohippuric acid-$^{131}$ I의 동위원소 교환법에 의한 제조과정에서 o-iodohippuric acid가 o-iodobenzoic acid로 변환되지 알음을 확인하였으며 Hippuran-$^{131}$ I의 방사화학적 순도 결정을 위한 간편한 방법을 제시하였다.