Abstract: Determination of content of octadecylamine hydrochloride in KCl saturated solution with orange Ⅱ spectrophotometric method was studied.Factors that affecting the test results such as the amount of buffer solution and indicator,and the time for stabilizing the chromogenic reaction were investigated;and the optimized experimental conditions were identified.Results indicated that the maximum absorption wavelength of the complex formed by octadecylamine hydrochloride and orange Ⅱ is 485 nm that showing good linearity with regression equation of y=0.063 7x-0.068 9.The correlation coefficient is 0.991 3.The relative standard deviation of quantitative analysis method is 1.53%.

Key words: octadecylamine hydrochloride, spectrophotometric method, quantitative analysis