Eluent Conditions for RSpak NN-series

Following eluents can be used for RSpak NN-series:
(a) Buffer
(b) Buffer + salt
(c) Buffer + polar organic solvent
(d) Buffer + salt + polar organic solvent
Separation of the sample can be controlled by changing eluent.

1)Water / polar organic solvent
The elution time of substances which have long alkyl chain or benzene ring is rather long. The elution time of such substances can be shorten by raising the concentration of polar organic solvent.

2) pH
In the case of basic substances, the lower the eluent pH value, the faster the elution time.

3) Salt concentration
In case of basic substances, the higher the salt concentration of the eluent, the faster the elution time.

4) Column temperature
The elution time of ionic substances changes according to the temperature.

(1)The eluent should be filtrated before being used. Especially, in the case of the eluent In which salt is dissolved, it is important to filtrate the eluent.
(2) The maximum concentration of organic solvents, methanol, ethanol and acetonitrile is 50%(V/V).
(3) The maximum concentration of salt is 0.5M.
(4) The pH range of eluent should be 2.0 to 12.0. In the case of eluent containing chlorine ions, the pH should be 4.0 or higher.
(5) Strong acids, strong bases and perchloric acid should not be used.
(6) When the eluent is replaced from the eluent containing no organic solvent to the eluent containing organic solvent, or reverse way, flow rate should be 0.5m1/min or slower.