ISOTHERM CONSIDERATION OF PAHS ADSORBED ON POLYMERIC CAPILLARY TUBINGIN AN AQUEOUS SAMPLE PRECONCENTRATION

This study examined the isotherm of polycyclic aromatic hydrocarbons ( PAHs) adsorbed on capillary concentrating tubing. Equations for common adsorption isotherms, including Langmuir and modified Freundlich, wer e used to fit the adsorption data obtained from pyrene and acenaphthen e samples. Each fitting's correlation coefficient was then used to ass ess the appropriateness of the isotherm of interest. Experimental resu lts indicate that the modified Frundlich isotherm most aptly accounts for monocomponent PAH adsorption from water onto ethyl vinyl acetate t ubing. From the appropriateness of the Langmuir isotherm individually in low-and high-concentration ranges, multilayer adsorption apparently occurs at a higher concentration. In bicomponent adsorption, acenapht hene was highly competitive with pyrene at a higher competition coeffi cient. In addition, the competitive coefficient of an analyte increase d with decreasing competitor concentration.