Experiments performed with biological systems require a buffer that will not interfere with the stability and activities of the biological components. In 1966, Norman Good and his colleagues began a series of investigations that established criteria for new zwitterionic buffers that would be optimal for experimentation with biological systems. These criteria include:

a. pKa between 6 and 8
b. highly water soluble
c. minimally permeable to biological membranes
d. minimal effects of salt concentration
e. minimla effect of temperature on pKa
f. minimal effect of concentration on pKa
g. minimal interaction with metal ions
h. nontoxic
i. high chemical stability
j. minimal absorbance between 240-700 nm

Required:
Write down the property that does meet Good's criteria for biochemical buffers.