测定方法如下:根据ISO 2271中描述的直接两相滴定程序，用苯乙酰氯溶液滴定样品溶液中的aliquiot部分。通过在碱性条件下回流第二份样品溶液进行水解。如前所述，用氯化苯乙铵溶液滴定未水解的阴离子活性物质。根据所得结果计算可水解和不可水解阴离子活性物质的含量。

The determination is carried out as follows: Titration of an aliquiot portion of a sample solution with benzethonium chloride solution according to the direct two-phase titration procedure describes in ISO 2271. Hydrolysis by refluxing under alkaline conditions of a second aliquot portion of the sample solution. Titration of unhydrolyzed anionic-active matter with benzethonium chloride solution as before. Calculation of the contents of hydrolyzable and non-hydrolyzable anionic-active matter from the results obtained.