Spectrophotometric Simultaneous Determination of Phenol and Salicylic Acid with Dualwavelength Linear Regression

Objective To explore the spectrophotometric simultaneous determination of phenol and salicylic acid . Methods In the buffer solution of (CH2)6N4,salicylic acid revealed absorption peak at 269.5 nm and interfered with determination of phenol. Two wavelengths for 295.5 nm,268.5 nm were selected as determining wavelength after preliminary test. Dualwavelength linear regression method was established for determination of phenol and salicylic acid. Five groups of mixture standard solutions were prepared as uniform design,the fitting cure equation was given after determining those mixture standard solutions. At the same time,the content of phenol and salicylic acid in five simulation mixture samples were determinationed. Results Linear relationship was observed at concentration of phenol and salicylic acid with 0-70 μg/ml,both at 295.5 and 268.5 nm. The method showed higher relative error at low concentration of phenol and salicylic acid,but not more than 2%. Conclusions The test indicated that the system is stable,the result is reliable. This method can be used for determination of phenol and salicylic acid in the wastewater.