Partial Least-squares(PLS) method together with UV-vis spectrophotometry is applied to simultaneous determination of phenol,p-methoxyphenol and,α-naphthol in aqueous solution.And the competitive adsorption of these compounds on carbon nanotubes is studied by this method.The results show that the recovery is 96%~107.6% and is satisfying.The concentration and adsorptive amount of phenol,p-methoxyphenol,and α-naphthol computed by PLS method are closely consistent with them computed by Langmuir Competitive Adso...