Hepes Buffer analysis

[kurian]

I would like to analyse the Hepes.
My method is issue to Dionex amperometric instrument with a Dionex Amino pac PA10 , but my Limit of Detection is just 5 µg/ml .
I wish to decrease this limit.
Somebody can help me ?

Thanks before

Kurian

[kurian]

If MK can help me.
I've just see he has the same problem long time ago but i cannot contact her by private message.