Buffer

Description

A chemical or combination of chemicals that minimizes the change in pH of a solution when an acid or alkali is added. Buffers are usually a weak acid (or base) paired with its conjugate salt. Many natural substances, such as sea water, soil and blood contain buffers. Examples of buffer pairs are:

- Acetic acid / Sodium acetate: buffers at 4.6

- Monobasic potassium phosphate / dibasic sodium phosphate: buffers at 6.8

- Ammonium chloride / Ammonium hydroxide: buffers at 9.2

- Sodium bicarbonate / Sodium carbonate: buffers at 10.0

Synonyms and Related Terms

"Puffer (Deut.); tampon (Fr.); pH buffer; buffers

Authority

• Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993

• Richard C. Wolbers, Nanette T. Sterman, Chris Stavroudis, Notes for Workshop on New Methods in the Cleaning of Paintings, J.Paul Getty Trust, Los Angeles, 1990

• Bernard Toale, The Art of Papermaking, Davis Publications, Portland OR, 1983

• Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976

• Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997

• The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998

• Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000