PDA spectrum of compound- 2nd derivative?

Discussions about chromatography data systems, LIMS, controllers, computer issues and related topics.

2 posts Page 1 of 1
When running a degradant sample on the PDA Detector, can you put much store in the second derivative view? Example: I have a peak that could be my active but degrading or breaking down somehow *6 months 40 degree sample*. The UV spectrum of the peak is not like the usual active UV spectrum BUT when you look at the 2nd, 3rd and 4th derivative the lamba max value is there.

Does this suggest that the active peak is there somewhere but is just degrading? Some people have said that 2nd derivative means nothing and that if you don't get the distinctive uv spectrum shape from the 1st derivative you cant make any assumptions. Thoughts?
Not really. It's just a sales kimmick!

A degradant can degrade further like an ester to the organic acid and still have the same (almost) spectrum. But, in order to get a 100% verifiable identification (derivatization or not) you need ~100 mAU pure peak for comparison (at 1/2 height). So the peak height of the sample is very important and only good chromatography will solve this.
2 posts Page 1 of 1

Who is online

In total there is 1 user online :: 0 registered, 0 hidden and 1 guest (based on users active over the past 5 minutes)
Most users ever online was 1117 on Mon Jan 31, 2022 2:50 pm

Users browsing this forum: No registered users and 1 guest

Latest Blog Posts from Separation Science

Separation Science offers free learning from the experts covering methods, applications, webinars, eSeminars, videos, tutorials for users of liquid chromatography, gas chromatography, mass spectrometry, sample preparation and related analytical techniques.

Subscribe to our eNewsletter with daily, weekly or monthly updates: Food & Beverage, Environmental, (Bio)Pharmaceutical, Bioclinical, Liquid Chromatography, Gas Chromatography and Mass Spectrometry.

Liquid Chromatography

Gas Chromatography

Mass Spectrometry