dionex problem

[stanlee]

Trying to set up Dionex Ion Chromatography method using Integrated amperometric detection and the Aminopac PA10 columns (gradient: water:0.25M NaOH:1.0M Na Acetate). Using disposable Au electrode which disintegrated in 24hrs, can anyone suggest why ?

[Jennifer Kindred]

Please verify that you have the right cell configuration for running disposable electrodes. This includes a blunt contact pin
(PN 045939 "pogo") and a specially designed blank holder block (PN 060297) for disposable electrodes.
The older design of the pin has three sharp points and needs to be replaced by a newer version of contact pin with a round top.
Even if it is possible to use a non disposable electrode as a holder block, we do recommend the blank block for a problem-free operation.

As with any other electrode, one should also make sure that the reference electrode potential is still in the acceptable range (<30mV drift). This can be confirmed by checking the reference electrode from the system against an unexposed reference electrode. The procedure is described in the detector manual.

Another possible cause of problems could be an incorrect waveform. The correct waveforms for carbohydrate and amino acid detection are in document number 060540 which you can obtain from Dionex. Please get in touch with Dionex service if the electrodes do not last at least five days of continuous use.

Petr Jandik
Dionex Corporation
Sunnyvale, CA