• British Pharmacopoeia Volume IV
  • Appendices
  • Appendix I A. General Reagents

Litmus Paper, Red
scroll to previous hit
scroll to next hit

Litmus Paper, Red To the extract obtained in the preparation of blue litmus paper add 2m hydrochloric acid dropwise until the blue solution turns red. Impregnate strips of filter paper with the solution and allow to dry.

Complies with the following test.

Sensitivity Immerse a strip, 60  mm  ×  10  mm, in 100  ml of 0.002m sodium hydroxide. On shaking, the paper turns blue within 45 seconds.