High cell current

[smartin]

Hi everyone,

Although I'm new in this forum, I think it's a great opportunity to share knowlege.
Now, I need some urgent help with electrochemical detector!!!!!
I'll be very gratefull if anyone can help me.

I have a very high cell current, what prevents me from having determinations with adequate sensitivity and specificity. I have cleaned the cell, replaced the buffer, optimized the potentional, refilled salt bridge with wet KCL crystals, and replaced the column, but the problem persists.

Can anyone help me? Anyone can tell me what is the expirity of the cell?

I will be very grateful to recieve any information that may help me.

Thanks!!!!

[smartin]

Please, can anyone help me???

Thank you very much!!!

[AA]

ECD Noise Reduction Tips (not in any order)

Make sure that your system has been previously washed (with 30% H3PO4) and then passivated with nitric acid (6 N) before beginning. This cleaning procedure is for the LC system only, not the flow cell or column.

Columns must be washed prior to use. Run 80:20 Methanol/Water at 0.5mL/min over the weekend (no recycling, this is cleaning not equilibration) at least and approximately, 500 column volumes.

As the column ages, noise will reduce, new columns always generate higher noise.

Do not recycle solvent.

Remove steel sinkers, replace with plastic ones.

Highest quality water, buffers, reagents should be used.

Use a dedicated set of glassware for buffer prep, filtering and such.

Do not let the waste line drip, have it in contact with the side of the waste container.

[smartin]

Thank you very much!!! It's a great help!!!!

I've just done most steps that you explain.
But I have some questions about your tips:

- Do you have a detailed method of cleaning and passivation of the HPLC system?

- You say that new columns always generate higher noise.... So, when using a new column, is it possible that the equilibration time last long? Even weeks?

Thank you!!