This tool has helped you make litres of buffer.

This calculator has now moved to its new home (phbuffers.org), because I have retired from the University of Liverpool and want to keep it going as long as possible. In time, I'll try to add more buffer resources to this page.

In fact, the original version of the software was written to support this book (on the right). To be honest, it really doesn't really sell any more, and I'm trying to get the publishers to give me back copyright, so I can release an e-book for free.

You are likely to have arrived here via the University of Liverpool. This route may not be stable. Please make a note of, and change any shortcuts, to: http://phbuffers.org/BuffferCalc/Buffer.html
Stacks Image 1432

The main purpose of the site is to give access to the software written for the design of thermodynamically corrected buffers. The software-
  • Provides a recipe for a range of monoprotic buffers used in biological systems
  • Makes corrections for the temperature at which the buffer will be used
  • Makes Debye-Huckel corrections for the effect of ionic strength on pKa
  • Describes two ways (titration or by accurate weight) for preparation of the recipe

Choose the buffer species you want to use, and enter parameters for volume, pH, and concentration of buffer species. Then, include the option to modify the ionic strength by addition of neutral salt. Finally, enter the temperature at which you'll use the buffer, and the temperature at which you'll make it up (these are often not the same). The 'Recipe’ button will then open a new window with a recipe, that you can print, or if you wish, copy the information to a lab notebook. Here's the calculator-

Buffer species
Volume
pH
Concentration  mM
Control of ionic strength?   (Yes, if checked)
Ionic strength  mM
Control ionic strength with
Prepare buffer at T=  °C
Use buffer at T=  °C