Chromatography Forum

A new colleague asked me if I could run a high/low assay for him. I am unfamiliar with the process, so I asked him for more detail. He said I must first inject samples of differing known concentrations to develop a responce curve. He did not perform the testing so could provide no more information. I currently do not do any quantitive analysis so I am unfamiliar with the process.
I am running Waters 2695's with uv PDA detectors. Can anyone enlighten me or provide a link to learn about the process. I would appreciate any insight you could provide.

Thanks

It sounds like an assay run using a calibration curve ie standards run at 50%-150% target concentration.

You run the sample at two different concentrations, a low concentration for reliable quantitation of the active, and a high concentration for detection and better quantitation of trace levels of degradants or impruties, say at < 0.1%.

The high-low procedure is explained at:

E.L. Inman & H.J. Tenbarge, J. Chromatogr. Sci. 26 (1988) 89.