Simultaneous determination of 3,4-dimethoxybenzaldehyde and 3,4-dimethoxyphenylacetone in industrial waste waters by high-performance liquid chromatography diode array detection

The environmental pollutants 3,4-dimethoxybenzaldehyde (DMB) and 3,4-dimethoxyphenylacetone (DMPA) were separated and quantitatively determined in treated and untreated industrial waste waters on a porous graphitized carbon column using HPLC with diode array detection (DAD). It was established that the detector response is linear in a wide range of injected quantities for both pollutants, and the logarithm of the capacity factor depends linearly on the concentration of acetonitrile in the eluent. The relative standard deviation of the retention time, peak height and peak area was lower than 1% in the normal and lower than 3% in the lowest concentration range. Peak purity tests indicated that the method separates well DMB and DMPA from other impurities present in the waste waters. Both aerobic and anaerobic treatments markedly decreased the concentration of DMB and DMPA in industrial waters and HPLC combined with DAD proved to be an adequate analytical procedure to follow such changes.