N. Marquez et al., OPTIMIZATIONS OF HPLC CONDITIONS TO ANALYZE WIDELY DISTRIBUTED ETHOXYLATED ALKYLPHENOL SURFACTANTS, Journal of liquid chromatography, 17(5), 1994, pp. 1147-1169
Commercial ethoxylated alkylphenol surfactants are always a mixture of
oligomers with different ethylene oxide number (EON). The different o
ligomers can be separated by various HPLC techniques. Isocratic mode w
ith mixed solvent on silica column allows to separate oligomers up to
EON = 10; gradient programming moves the limit up to EON = 15. For hig
her EON values (up to 25) a NH2 column has to be used, either with iso
cratic or gradient mode. Applications to the analysis of microemulsion
systems and to the separation of tributyl phenol ethoxylates are disc
ussed. Extreme separation of wide range EON distribution is attained w
ith two columns (Si and NH2) in series, and a solvent programming.