Preconcentration with membrane cell and adsorptive polarographic determination of phenols in air

The present paper describes a procedure that phenols in air were preconcentrated in a membrane cell and their content was determined by adsorptive polarography. First, the phenols in air samples were preconcentrated in a membrane cell using 2.0 M NaOH solution, then in a pH 1.3 buffer solution p-bromophenylamine forms a diazoate with NaNO2, and into the mixture the collected phenols were added to form azo-compound in a pH 13 buffer solution. The azo-compound can be adsorbed at the mercury electrode and yields a sensitive oscillopolarographic wave. Over the range 2.0×10−8–2.0×10−5 M, the peak currents are linearly proportional to the concentration of phenols. The detection limit is 5.0×10−9 M.