Abstract

A sensitive and relatively interference-free spectrometric method for determination of formaldehyde in leather wastewater is described. The method is based on the combination of chromotropic acid with formaldehyde under acidic conditions with heating. The absorbance of the complex is measured spectrophotometrically at 390nm. Chemical factors and FIA variables affecting the system are also discussed. The linearity concentration range of the calculation curve was from 0.05 to 1000mg l-1 of standard solutions. The relative standard deviation was 0.42% (n = 11) obtained by injecting 200∝g l-1 standard formaldehyde solution. The detection limit was 0.003mg l-1 calculated from three times the average background noise. The proposed method was successfully applied to determine formaldehyde in varied samples of leather wastewater.