Buffer solutions - standard solutions for pH measurement
pH buffer are stable aqueous mixtures of basic and acidic salts that are not completely dissociated and tolerate small additions of acids or bases by shifting the dissociation without a significant change in their nominal value. They have a defined value to which the potential of a pH electrode is compared.
The worldwide valid standard buffer solutions are referred to as “DIN/NIST Buffers” according to DIN or other standardization institutes listed in the corresponding standards with their formulation. The second type of buffers, which is much more common but, unlike DIN/NIST buffers, is subject to manufacturer-dependent formulations, are known as “Technical Buffers”.