I have prepared 11 citrate buffer solutions covering pH 4 to 5 in 10 minutes [using Buffer Maker]. My supervisor couldn't believe it is possible!

Ute Becker

Buffer Maker - information on built in buffer database

Program has built in database, that keeps several types of information.

The most important part of the database holds information about acids and their dissociation constants. Quality of information stored there is paramount to the accuracy of recipes calculated by Buffer Maker. We used several sources of dissociation constants - including (but not limited to) famous Norman Good paper, Buffer solutions by R.J. Beynon and J.S. Easterby and Handbook of chemical equilibria in analytical chemistry by S. Kotrlý and L. Šůcha.

Note, that to simplify model used in pH calculations we treat all substances consistently as Brønsted-Lowry acids. However, you can enter data as acid dissociation constants (be it Ka or pKa), base dissociation constants or even protonation constants. Program will automatically convert these all to the values it uses internally.

To help you recognize formulas of substances used in the program, we decided to let you define your own moieties - after all, it is much easier to recognize H3Citrate as citric acid, than C6H8O7 (which can be several other things as well). This is especially important when dealing with popular biochemical buffers like PIPES, TAPS, HEPES and so on - their abbreviated names are recognized worldwide, their formulas (and chemical names) are virtually unknown.

Database objects that you will see most often - buffers and reagents - are just a convenient way of mixing acids and combining them into buffers. Each reagent is a mixture of acids - sometimes simple, like hydrochloric acid, sometimes much more complicated, like potassium sodium tartrate (which is treated internally by the program as a mixture of three acids - tartaric and two conjugate acids of strong bases NaOH and KOH).

At the time of writing Buffer Maker database contained about 65 acids, 170 reagents and over 100 buffers. These number are likely to change in the near future, besides, you are not restricted to acids, reagents and buffers already present in the database, as Buffer Maker comes with a series of editors, that allows you to enlarge or improve database any time. In fact program database was prepared using just these editors, there was no need for any additional or external tools.

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