Determination of purity of compounds by extraction-solubility.

Thirty-three organic compounds prepared for use as analytical standards were examined for purity by the extraction-solubility method. Of these, twenty-one gave satisfactory results, seven behaved non-ideally, and five were not soluble in the useful range. Results on the twenty-one satisfactory samples compared favourably with those obtained by differential scanning calorimetry and other analytical methods. The method was found to be useful for following the improvement of compounds undergoing purification.