Chromatography Forum

Hi there,

I have a query about what derived channels should be used to process peak purity results from. Our company seems to have adopted processing a derived channel from either 1) MaxPlot or 2) the prescribed (single) analytical wavelength for the method being interrogated.

Q/ If you were writing a SOP / instructional document what would you prescribe and why?

We understand that you would use MaxPlot to set/check for a suitable noise region and to ensure maximum absorbances aren’t above 1 AU. However, does it matter what derived channel is used for actual peak purity processing? Peak integration would be (slightly) different between the two derived channels, but for actual peak purity determination wouldn’t you get to the same result (more often than not) regardless of what derived channel was processed?

Hi Rob,

You are correct, peak purity results will not be impacted by the choice of Derived Channel used in reprocessing the data.

For an SOP, I would go along with what you suggest above, "the prescribed (single) analytical wavelength for the method being interrogated", as this is the relevant measurement wavelength for the method(s) being validated.