Buffer #

All buffers should be prepared freshly on the day required. Two reasons:

1. pH is affected by prolonged storage.
2. there is microbial growth present.

Buffer shelf life reference: pharmacopoeia monographs or similar.

Buffer reagents can contain a stabilizing agent, for example, sodium metabisulphite. These stabilizing agents often affect the optical and chromatographic behaviour of buffer solutions, so it is often worth buying reagents that contain no stabilizer. Containers of solid reagent are easily contaminated by repeated use. For this reason, we recommend that regents be purchased in low container weights.