Peroxide testing

Preparation

• Samples containing more than 25 mg/L H2O2 (Cat. Nos. 110011) or 100 mg/Ll H2O2 (Cat. No.110081) must be diluted with distilled water or peroxide-free ether.

• The pH of the aqueous sample must be within the range 2-12 If necessary, buffer the sample wit sodium acetate or, respectively, adjust the pH with hydrochloric acid

Test Procedure

• For aqueous solutions:

  • Immerse the reaction zone of the test strip in the pretreated sample (15 – 30 C) for 1 sec.
  • Allow excess liquid to run off via the long edge of the strip onto an absorbent paper towel and after 15 sec (Cat. No. 110011) or after 5 sec (Cat. No. 110081) determine with which color field on the label the color of the reaction zone coincides most exactly.
  • Read off the corresponding result in mg/L H2O2

• For organic solvents:

  • Immerse the reaction zone of the test strip in the pretreated sample (15 – 30 oC) for 1 sec.

  • After the solvent has evaporated (gently fan the strip back and forth for 3 – 30 sec), immerse the reaction zone in distilled water for 1 sec and allow excess liquid to run off via the long edge of the strip onto an absorbent paper towel.

  • After 15 sec (Cat. No. 110011) or after 5 sec (Cat. No. 110081) determine with which color field on the label the color of the reaction zone coincides most exactly.

  • Read off the corresponding result in mg/L H2O2

General Notes

• any blue within 3 minutes is a positive result

• If the color of the reaction zone is equal to or more intense than the darkest color on the scale or in another color emerges, repeat the measurement using fresh samples diluted with distilled water or, respectively, peroxide-free ether until a value of less than 25 mg/L/ H2O2 (Cat. No. 110011) or 100 mg/L (H2O2) (Cat. No. 110081) is obtained.

In the case of Cat. No. 110081 the reaction zone indicates values within the measuring range also for H2O2 contents from 5000 mg/L (0.5 %) up.