Determination of Chlorine and Chlorine Dioxide by Non-Suppressed Ion Chromatography and Application to Exposure Assessment in the Paper Industry

A non-suppressed ion chromatography method for the determination of chlorine and chlorine dioxide by their representative ions, chloride and chlorite, has been developed. The method utilizes a phosphate buffered iodide solution for the absorption of chlorine and chlorine dioxide from air and conversion to their representative ions. Analysis is by non-suppressed ion chromatography with a 1-hexane sulfonic acid, sodium salt mobile phase and detection by conductivity. The analytical detection limit was found to be 0.16 μg/mL and 0.13 μg/mL for chloride and chlorite, respectively. The method was adapted for use in a passive sampler and used to assess exposure to chlorine and chlorine dioxide at four pulp / paper mills. A total of 336 personal exposure samples were collected of which 25.2% had detectable levels of chlorine and 3.9% had detectable levels of chlorine dioxide. For those samples with detectable exposures, the overall geometric means and standard deviations were GM = 38 ppb, σ g = 2.5 and GM = 33 ppb, σ g = 2.5, for chlorine and chlorine dioxide, respectively.