Is the Determination of Chloroform Accurate at High Chlorine Concentrations by Gas Chromatography with On-Column Injection and Electron Capture Detection?

The organic substances most frequently reported as precursors of trihalomethanes in public water are naturally occurring humates found in surface water and groundwater. Algae may be potent trihalomethane precursors during chlorination for drinking water and react readily with chlorine to produce trihalomethanes. The objective of this paper is to present the difficulty of determining chloroform when chlorine concentrations up to 5 mg/L were used to chlorinate algae cultures. Sodium hypochlorite was fortified with known concentrations of chloroform. The response obtained by gas chromatography using on column injector gave a peak that coeluted with chloroform that was probably due to water and oxygen and preventing the accurate determination of chloroform.