Sodium Chlorite Laboratory Preparations of …

1 Basic Chemicals 600-102 Sodium Chlorite 04/2019 Important: The information presented herein, while not guaranteed, was prepared by technical personnel and is true and accurate to the best of our knowledge. NO WARRANTY OF MERCHANTABILITY OR OF FITNESS FOR A PARTICULAR PURPOSE, OR WARRANTY OR GUARANTY OF ANY OTHER KIND, EXPRESS OR IMPLIED, IS MADE REGARDING PERFORMANCE, SAFETY, SUITABILITY, STABILITY OR OTHERWISE. This information is not intended to be all-inclusive as to the manner and conditions of use, handling, storage, disposal and other factors that may involve other or additional legal, environmental, safety or performance considerations, and Occidental Chemical Corporation assumes no liability whatsoever for the use of or reliance upon this information.

2 While our technical personnel will be happy to respond to questions, safe handling and use of the product remains the responsibility of the customer. No suggestions for use are intended as, and nothing herein shall be construed as, a recommendation to infringe any existing patents or to violate any Federal, State, local or foreign laws. 14555 Dallas Parkway, Suite 400 Dallas, TX 75254 800-752-5151 Sodium Chlorite Laboratory Preparations of Chlorine Dioxide Solutions There are two common methods used to prepare Laboratory solutions of chlorine dioxide.

3 The choice of method depends upon required purity of the resultant solution. Method I produces a material equivalent to that produced by most commercial chlorine dioxide generators. Method II produces a reagent grade, chlorine dioxide solution with no free chlorine and is used for instrument standards and for studies where free chlorine would interfere. Chlorine dioxide solutions should be protected from sunlight (ultraviolet light) and heat. Chlorine dioxide solutions can be stored in amber bottles in a refrigerator for some time.

4 A gradual decrease in chlorine dioxide concentrations will occur due to volatilization and decomposition. Precautions: The chlorine dioxide solution concentrations produced in these procedures are high enough that a small amount of chlorine dioxide gas may escape to the air. Since chlorine dioxide is an irritating oxidizer, always work in a well-ventilated hood. Method I: preparation of Technical-Grade Chlorine Dioxide Solutions. Purpose: To prepare chlorine dioxide solutions (approx. 2000 ppm) typical of those produced by most chlorine dioxide generators.

5 These solutions may be used for studies that do not require "chlorine-free" chlorine dioxide solutions. Summary: Chlorine dioxide (ClO2) is produced from the oxidation of Sodium Chlorite (NaClO2) by hypochlorous acid (HOCl). Hypochlorous acid is prepared by combining solutions of Sodium hypochlorite (NaOCl) and hydrochloric acid (HCl): NaOCl + HCl HOCl + NaCl Then: 2 NaClO2 + HOCl + HCl 2 ClO2 + 2 NaCl + H2O Combined Equation: 2 NaClO2 + NaOCl + 2 HCl 2 ClO2 + 3 NaCl + H2O Equipment and Reagents.

6 3-Volumetric Flasks, 1 liter Graduated cylinder, 25 ml Graduated cylinder, 100 ml 4-Amber reagent bottles, 1 liter Graduated cylinder, 50 ml Graduated cylinder, 250 ml Sodium hypochlorite solution, Technical Sodium Chlorite solution, (25%) Concentrated hydrochloric acid, 12N Solutions: Solution I: Dilute Sodium Hypochlorite Solution Dilute 63 mls of Sodium hypochlorite solution to 1 liter with DI water (store in amber bottle). Basic Chemicals 600-102 Sodium Chlorite 04/2019 Important: The information presented herein, while not guaranteed, was prepared by technical personnel and is true and accurate to the best of our knowledge.

7 NO WARRANTY OF MERCHANTABILITY OR OF FITNESS FOR A PARTICULAR PURPOSE, OR WARRANTY OR GUARANTY OF ANY OTHER KIND, EXPRESS OR IMPLIED, IS MADE REGARDING PERFORMANCE, SAFETY, SUITABILITY, STABILITY OR OTHERWISE. This information is not intended to be all-inclusive as to the manner and conditions of use, handling, storage, disposal and other factors that may involve other or additional legal, environmental, safety or performance considerations, and Occidental Chemical Corporation assumes no liability whatsoever for the use of or reliance upon this information.

8 While our technical personnel will be happy to respond to questions, safe handling and use of the product remains the responsibility of the customer. No suggestions for use are intended as, and nothing herein shall be construed as, a recommendation to infringe any existing patents or to violate any Federal, State, local or foreign laws. 14555 Dallas Parkway, Suite 400 Dallas, TX 75254 800-752-5151 Solution II: Dilute Hydrochloric Acid Solution Add 8 mls of concentrated (12N) hydrochloric acid to 500 mls of water in a 1 liter volumetric flask.

9 Mix and make up to volume with DI water (store in an amber bottle). Solution III: Dilute Sodium Chlorite Solution Dilute 26 mls of Technical Sodium Chlorite Solution to 1 liter with DI water (store in an amber bottle). Procedure: 1. Prepare the dilute solutions shown above. 2. Pour 250 mls of dilute Sodium hypochlorite solution into a 1 liter amber reagent bottle. 3. Add 250 mls of dilute hydrochloric acid solution to the reagent bottle, mix. 4. Add 250 mls of dilute Sodium Chlorite solution to the reagent bottle, mix.

10 5. Store the chlorine dioxide solution in a closed amber bottle in a refrigerator. Properly stored solutions may be used for weeks, but should be standardized daily, prior to use, by an approved method1. Figure 1 Generation Setup for Method II Method II: preparation of Reagent-Grade Chlorine Dioxide Solution Purpose: To prepare low concentration (<1000 ppm), chemically pure, chlorine dioxide solutions for use as instrument standards or for studies, like trihalomethanes (THM) abatement studies, where the possibility of any chlorine contamination must be avoided.