本實驗室應用中央標準局所採用的吸引法，以探討氨態氮最適當之測定方法及步驟。由實驗過程，吾人發現氨態氮抽出量隨時間，溫度 (60℃以內) 之增加而提高，而且當鹼度提高時，也可得到較好之回收率。
由結果得知，以硫酸銨及氯化銨等之銨鹽類當標準品質來測定時，氨態氮抽出量在 60℃及 10N之氫氧化鈉液作用下，在15至30分鐘內即可得到98%以上的回收率。然而甘胺酸及一些胺基酸相關化合物有些干擾，但其影響不大，在分析上應不致發生問題。 This communication presents the results from the study on the searching of optimum conditions for the determination of free ammonia contents by suction method, which have authorized by CNS. We found that the amount of free ammonia extracted from the sample was increased as the period and temperature (up to 60℃) of extraction were increased. Furthermore, the ammonia recovery can be improved when the alkalinity of sample solution is increased.
Results obtained in this study reveal that at the extraction temperature of 60℃ and in the presence of 10 N of NaOH, an yield of more than 98% of free ammonia presented in the salts tested (NH4Cl and (NH4)2SO4) can obtained in 15-30 min. Glycine and some amino-acid related substantces tested show little or no interference.
