Chromatography Forum

My company recently bought an HPLC system that uses an ELSD detector to measure ammonia concentrations in water. They want it to be very high precision. Is this sort of thing possible?

I've been just playing around with it and my HPLC experience is limited, but I don't feel too optimistic. Right now they're not using a column and are injecting directly into the detector.

Ammonia (or, more properly, the ammonium ion) can be determined using a cation exchange column and a conductivity detector.

An ELSD would definitely *not* be a good choice because ammonia is volatile.

You can analyze ammonia and other simple amines with ELSD if you use TFA in the mobile phase:
http://www.sielc.com/Compound-Ammonia.html

detection limit is probably around 20 ppm. You will need to set up temperature in your ELSD at 30-35*C