This document specifies a method for determining the content of water-soluble primary and secondary amines in surfactants. It is suitable for the determination of a range of water-soluble primary and secondary amines in surfactants, such as 1-amino-2-propanol, monoethanolamine, methyl monoethanolamine, etc. The determination of tertiary amines is not within the scope of application of this document. The principle of the method is that under the conditions of alkaline and chilled down with ice water, the primary or secondary amines react with benzoyl chloride to form benzamide, which is then separated and detected by liquid phase chromatograph. The results are calculated according to the External standard method. Unless otherwise stated, only reagents confirmed to be analytically pure and water of grade 3 or above specified in GB/T 6682 can be used. Common reagents include primary or secondary amine standard sample, N, N-dimethyl-1,3-propanediamine standard sample, acetonitrile, benzoyl chloride, sodium hexane sulfonate, etc.