Alkali Buffer, 3.0 N, 100 mL

For ultrapure saturated NaCl feed brine used in the Chlor-alkali industry. Not for water or a non-saturated brine solution. Calcium and other polyvalent cations can foul the ion-exchange membranes used in electrolytic manufacture of chlorine and alkali from brine. The HNB method has an indicator dye that is blue in strongly alkaline brine and changes to red when complexing free calcium and magnesium. EDTA added to a portion of the reacted sample complexes the calcium and magnesium and sets a reference point. Because metal standards are not stable in saturated alkaline brine and brine matrices are variable, the method is calibrated using standard additions for each type of brine and for each new lot of reagents. 3.0 N. Bottle/100 mL. Also requires item numbers 2307300 (HNB Reagent Package), 2241926 (EDTA solution), and 2305442 (calcium standard, 10 mg/L).