Differences between strong and weak ion exchange media?
Strong exchange media (SAX and SCX) display little or no sensitivity to pH variations of the matrix that they are in contact with; their groups remain constantly charged, allowing ion exchange with the sample compound(s). Conversely, weak exchange media (WAX and WCX) are comprised of pH variation-sensitive groups. If the pH varies too widely, the sorbent's exchange function is neutralized. These weak exchange media are used to trap strong acids or bases that would otherwise bind too tightly to SAX and SCX media.