Eluent Conditions for Asahipak ES-series

Total salt concentration for Asahipak ES series should generally be 20 to 600 mM. Do not use pure water alone, as it would result in column degradation. Buffer solutions generally used in ion-exchange chromatography with the ES column are of the types and concentrations shown in the following tables:

pH	Asahipak ES-502C 7C
3.8 to 4.3	Sodium formate
4.3	Sodium succinate
4.8 to 5.2	Sodium acetate
5.0 to 6.0	Sodium malonate
5.5 to 6.7	MES
6.7 to 7.6	Sodium phosphate
7.6 to 8.2	HEPES
8.2 to 8.7	BICINE

pH	Asahipak ES-502N 7C
4.8 to 5.0	N-Methylpiperazine HCl
5.0 to 6.0	Piperazine HCl
5.8 to 6.4	Bis Tris HCl
6.4 to 7.3	Bis Tris Propane HCl
7.3 to 7.7	Triethanolamine HCl
7.5 to 8.0	Tris HCl
8.0 to 8.5	N-Methyldiethanolamine HCl
8.4 to 8.8	Diethanolamine HCl
8.5 to 9.0	1,3-Diaminopropane HCl
9.0 to 9.5	Ethanolamine HCl

MES: 2-(N-morpholino)ethanesulfonic acid
HEPES: 4-(2-hydroxymethyl)-1-piperazine ethanesulfonic acid
BICINE: N,N-bis(2-hydroxyethyl)glycine
Tris: tris(hydroxymethyl)aminomethane
Bis Tris : Bis(2-hydroxyethyl)iminotris(hydroxymethyl)methane
Bis Tris propane: 1,3-Bis[tris(hydroxymethyl)methylamino]propane

Salt solutions such as NaCl, KCl, Na₂SO₄ and K₂SO₄ may also be used either indepedently or in combination with these buffer solutions.