Qualitative and quantitative analysis of alkylphenol polyethoxylates in solution via UV spectroscopy

For investigating the test method of alkylphenol polyethoxylates(APnEO) in solution,a comparative study of UV absorption characteristics of nonylphenol ethoxylates(NPEO) and octylphenol ethoxylates(OPEO) was performed using UV spectroscopy.The spectroscopy analysis showed that the spectroscopic curve of the two chemicals has no significant differences,as their characteristic absorption peaks exhibit at 275 nm and 224 nm,that can be used for qualitative and quantitative analysis of APnEO in the solution.For the absorbance at 224 nm,it has higher sensitivity but narrow linear range of APnEo concentration,while for the absorbance at 275 nm,it has relatively low sensitivity but wide linear range of APnEo concentration.The molecular weight of APnEO will affect the linear range of the concentration.