Abstract: This Paper deals with the determination of alkylphenolpolyoxyethylene ether and sodium alkylbenzenesulfonate in mixture by second derivative UV-spectrophotometric method. It is not necessery to separate the sample in the analytical process. This method is simple, convenient, fast and accuracy. Under the given experimental condition, the mean recoveries of alkyphenol-polyoxyethy-lene ether and sodium alkylbenzensulfonate are over 98%. The standard deviation is ±0.01.

Key words: Alkylphenol-polylexythylene ether, Sodium alkylbenzensulfonete, Second derivative