Comparison of Facts and DPD-Steadifac Procedures for Free and Combined Chlorine in Aqueous Solution

摘要

In a continuing effort to develop a superior colorimetric test procedure for determining free available chlorine in aqueous solution, a study was designed to compare the FACTS (Free Available Chlorine Test with Syringaldazine) with the recently modified DPD procedure, DPD-STEADIFAC. It was shown that the DPD-STEADIFAC and a minor modification are more specific for free chlorine in the presence of mono- and dichloramine than the DPD procedure. The DPD and DPD-STEADIFAC Modified procedure were shown to have comparable accuracy and precision. All of the test procedures showed intrusion of NC13 into the free chlorine reading. The lower limit of detection for the FACTS and DPD procedures were 0.014 and 0.021 mg/L as Cl2, respectively. (Author)