Abstract:
The purpose of this project was to investigate the performance of three
commonly used biological buffers; carbonate, phosphate and Tris, in the
presence of calcium. In calcium solutions having a concentration less than
0.011M , phosphate was determined to be a better buffer than carbonate
or Tris. This was determined because phosphate had the best buffering capacity
below 0.011M, meaning it had the smallest change in pH after the addition
of a strong acid. At calcium concentrations greater than 0.011M Tris was
proven to be the better buffer. Carbonate is not an effective buffer regardless
of calcium concentration.
The goal of this experiment was to determine the concentration of calcium
at which Tris becomes a better buffer than phosphate. This result indicates
which buffer should be used in certain biological applications based on
the concentration of calcium in the system. Other important points to consider
in determining which buffer to use are: the importance of the interaction
between the buffer and the component presence, in this case calcium; the
significance of the affect on the buffering capacity; the concentration
of calcium in the system; and the importance of maintaining this concentration.