Miniaturized closed reflux, colorimetric method for the determination of chemical oxygen demand

The standard technique for the closed reflux, colorimetric analysis of chemical oxygen demand (COD) utilizes several hazardous compounds, including mercury, silver, chromium, and sulfuric acid. A miniaturized version of this analytical technique was developed, thereby reducing the use and disposal of these hazardous compounds by 84%. The miniaturized method demonstrated a similar level of accuracy as the conventional technique for both synthetic and actual wastewater samples. This method for closed reflux, colorimetric analysis of COD therefore represents an excellent opportunity for hazardous waste minimization in environmental water quality laboratories without compromising analytical accuracy.