標準號：ISO 787-4-1981
中文標準名稱：顏料和體質顏料的通用試驗方法 第4部分:水萃取酸度或堿度的測定
英文標準名稱：General methods of test for pigments and extenders; Part 4 : Determination of acidity or alkalinity of the aqueous extract
標準類型：G53
發布日期：1999/12/31 12:00:00
實施日期：1999/12/31 12:00:00
中國標準分類號：G53
國際標準分類號：87.060.10
適用范圍：The principle of the method consists in the hot extraction of the material by following the procedure specified in ISO 787/3, to the stage of obtaining a perfectly clear filtrate. The determination is carried out with indicator solution (method A). If the solution with the methyl red indicator is yellow (alkaline), titrate it with the hydrochloric acid solution to an orange end-point; if the solution with the methyl red indicator is red (acid), titrate it with the sodium or potassium hydroxide solution to an orange end-point. The other method (method B) is the potentiometric determination. Take 100 ml of the test solution, insert the electrodes of the pH measuring device and read the pH value.