摘要：It is thought that large amount of sugar and amino acid interfere with the analysis (for example by GLC) of organic acid in foods. In this paper, the conditions of ion exchange treatment were investigated as the pretreatment method of organic acid analysis. Twelve organic acids usualy contained in foods were examined as samples, and a strongly acidic cation exchange resin and four anion exchange resins having different basisity were used as ion exchange resins. As the results, it was found that the pretreatment of organic acid analysis could be proceeded by the following method. The sample solution is flowed through the column of H-form cation exchange resin (amino acid is adsorbed), and successibly through the column of OAc-form anion exchange resin (organic acid is adsorbed and sugar is eluted). The organic acid adsorbed with the anion exchange resin can be eluted by 1N HCl. However, some acids such as levulinic acid and gluconic acid can't be completely adsobed with OAc-form anion exchange resins. In these cases, OH-form intermediate basic or weakly basic anion exchange resin must be used. Furthermore, OH-form strongly basic anion exchange resin can't be used as pretreatment resin, because it slightly adsorb sugar which is eluted into organic acid fraction and interfere with the analysis of organic acid.
