- You may try to concentrate your samples by adsorption on acid washed alumina. This may increase sensitivity to a measurable extent.

There are too many choices to be made:  sample preparation, column, mobile phase, electrode material, applied potential, column internal diameter.  There are perhaps 1000 papers (or more) that demonstrate this. I was one of the "inventors" of this method back in 1972, but many improvements have occurred since then.  In some cases LC/MSMS can also work well.  It is very important to know which amines: serotonin is different than dopamine, norepinephrine is different than epinephrine etc. Plasma is different than tissue.   It can be difficult to get good results without spending some time examining the literature and understanding electrochemistry to some extent.  Concentration detection limits below 1 ng/mL of plasma, for example, are very feasible, with experience and care to details.  Yes. As Sanket has suggested, many procedures involve a preconcentration step on a small amount of acid washed aluminum oxide. Many of these compounds are easily oxidized at physiological pH.  Often the first step is to lower the pH and precipitate proteins.

I should mention that compared to UV the limits of detection should be 100X lower and the very high selectivity for easily oxidized catechols will often make the difference betwen success and too many interferences in the chromatogram.... The most common applications are in brain tissue and plasma, but there have been many studies in kidney, adrenal glands, heart tissue, plants and insects as well.  Cheers... 

ECD is more sensitive than UV detection

Indeed, ECD for biogenic amines is for more sensitive and selective than UV detection. Generally, you can easily achieve LOQ of 10 nmol/L. The tricky part of ECD is the performance of the cell chamber (a good reference electrode and carefully polished carbon electrode).

Dear Sandeep,

I agree with all of the above comments, please find attached, an application note for catecholamines.  I hope that it is of use to you.

Kind regards,

Ade Kujore

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