Chromatography Forum

We run methods anywhere from 210 nm to 270nm on Waters 486 Detectors, PDA and 2487 Dual Wavelength detetors. One GMP consultant who audited our lab mentioned that we need to perform annual PQ accross the range of our use i.e. from 210 nm to 270 nm. I would be intereseted to find out if there is a particular compound that I can use to do the PQ across all the wavelengths. Please advise if anybody knows any compounds. Waters does OQ/PQ at 254nm using Uracil. The Waters PQ protocol I have talks about using Uracil and one article I have talks about ANTHRACENE.

Thanks in advance for your help.

I think that Holmium Oxide standards (filters) are commonly used for a considerable range of wavelengths. There are also procedures out there for potassium dichromate solutions where you calculate absorbtivity as a function of different concentrations and wavelengths.

Many HPLC's has internal holmium filter and you can check your accuracy from the diagnosis menu.

However, your assay wavelengths should ideally be in the standard range and holmium covers only 240-640 nm. Also, from GLP point of view your filter should be traceable and calibrated. At least I didn't have luck on trying to get a certificate..?

Any audit experiences out there? Is it ok to work on low UV and use only non-calibrated internal filters

Waters uses Coffeine to determine wavelength in their AQT program:
205 and 272 nm

I might be wrong, but I believe that caffeine is used for detector linearity, not for wavelength accuracy? Organic compounds have broad peaks in their UV scans and they are not suitable for wavelength accuracy testing. Whereas holmium oxide has several sharp peaks at 240-640nm suitable for testing the detector wavelength accuracy.

coffeine is used to determine system precision, wavelenght accuracy, detector accuracy and linearity, injection linearity and accuracy.

uracil is used to determine the flow rate linearity and accuracy

methyl paraben/uracil is used do determine the temperature accuracy

Good luck

Is it Coffiene or Caffiene for the Detector Accuracy test. Just wanted to get clarification before I go buy the chemical for the test. Thanks for all the information.
Thanks again