规定的方法直接适用于溶解在沸水中的材料或材料。如果固体化学品不易溶于沸水，则需要进行特殊的初步处理。应采取预防措施，以避免吸收水分和二氧化碳。所有试验和分析应在20°C的温度下进行。为避免错误结果，仅使用分析级试剂。取代ISO建议R 1686-1970

The method specified are applicable directly to soluted mateials or materials soluble in boiling water. In case of solid chemicals not readily soluble in boiling water, a special preliminary treatment is necessary. Precautions shall be taken in order to avoid absorption of moisture and carbon dioxide. All tests and analyses shall be carried out at a temperature of 20 °C. In order to avoid incorrect results use only reagents of analytical grade. Replaces ISO Recommendation R 1686-1970