Buffer solutions

Buffer solutions (synonym buffer mix) - solutions containing one or more buffer systems and is therefore able to maintain its pH (pH) at the same level in their dilution, concentration and addition of small amounts of strong acids or alkalis. Buffer system is a mixture of weak acid and its salts formed a strong base (for example, acetic acid CH3COOH and sodium acetate CH3COONa), or a mixture of weak base and its salts formed a strong acid (for example, a mixture of ammonium hydroxide NH4OH and ammonium chloride NH4Cl). PH buffer solution depends on the value of dissociation constants (see Electrolytes) weak acid or weak bases and on the ratio of the concentrations of the components forming a buffer system.
Buffer systems play an important role in the persistence of pH in fluids and tissues of the body.
The most important buffer systems of blood and tissue fluids include hemoglobin, a protein in the plasma as bicarbonate buffer (a mixture of carbon acid N2FROM3 , and bicarbonate-alkaline metal, for example NaHC03); phosphate buffer (a mixture of one-deputizing and disubstituted phosphates alkaline metals, for example NaH2P04 and Na2HP04), and other
Buffer solutions are widely used in laboratory practice in cases where one or another process (cultivation of bacterial cultures, the determination of the activity of the enzyme and so on) must be at a constant pH, and are used as standard solutions with known values of pH in measuring the pH of body fluids.
Cm. also, pH, Acid-base balance.