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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: PharmaStud. on April 20, 2022, 05:49:10 PM

Title: How to choose the detection wavelength for HILIC ?
Post by: PharmaStud. on April 20, 2022, 05:49:10 PM

Hello,

I have to analyze 5-fluorouracil and its impurities (5-methoxyuracil, barbituric acid and urea) by the HILIC method with a UV detector. But what I don't understand is how to choose the detection wavelength, 5-Fluorouracil, 5-Methoxyuracil and Barbituric acid absorb at around 265 nm. Urea is a molecule that is analyzed at 200nm because it does not absorb on higher wavelengths. As I have to analyze them by the same method, I don't understand which wavelength should I choose ? Should I choose the urea wavelength or choose a wavelength that is between 200 and 265 nm ?

Thanks,

Title: Re: How to choose the detection wavelength for HILIC ?
Post by: Babcock_Hall on April 21, 2022, 08:26:24 AM

Some detectors are able to monitor more than one wavelength.  Is that the case for your instrument?