A FLOW-INJECTION ANALYSIS TECHNIQUE FOR THE DETERMINATION OF CHLORIDEUSING REFLECTANCE DETECTION

A how injection (FI) determination for chloride has been developed usi ng the light reflectance of the precipitate formed by the reaction of chloride with silver(I) as the method of detection rather than turbidi metry, as in the previous FI method using this reaction. The dynamic r ange of the analysis is increased to 0-10 mM chloride with a 10 mM sil ver(I) reagent and to 0-50 mM chloride with a 50 mM silver(I) reagent by using this mode of detection. The ability to select the injected re agent from an option of two concentrations via the control program is incorporated into the FI system, enhancing the versatility of the anal ysis. The dynamic range is further extended to 100 mM chloride by meas uring the signal levels at the trailing portion of the response curve. The consumption of reagent is kept to a minimum by merging injected z ones of sample and reagent instead of using a constant reagent stream.