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

The present paper describes a procedure that phenols in air were preconcent rated in a membrane cell and their content was determined by adsorptive pol arography. First, the phenols in air samples were preconcentrated in a memb rane cell using 2.0 M NaOH solution, then in a pH 1.3 buffer solution p-bro mophenylamine forms a diazoate with NaNO2, and into the mixture the collect ed phenols were added to form ate-compound in a pH 13 buffer solution. The azo-compound can be adsorbed at the mercury electrode and yields a sensitiv e oscillopolarographic wave. Over the range 2.0 x 10(-8) -2.0 x 10(-5) M, t he peak currents are linearly proportional to the concentration of phenols. The detection limit is 5.0 x 10(-9) M. (C) 2000 Elsevier Science B.V. All rights reserved.