Tech Tip 28: Analysis of Unknowns - How? - Libraries! Part I: LC – DAD

In LC – DAD the ability to collect UV-Vis 'scan' data enables peak purity estimations, this combined with a retention time identifier gives an overall 3-dimensional output akin to GC-MS. Thousands of compounds are present in many libraries, covering applications from Environmental, through Pharma, Cosmetics, Pesticides and QC Testing. Of course, analysis of the 80% of all compounds not amenable to GC is easily possible by this technique!

The theory is based on an absorbance profile over a wavelength range!

Plus, many other parts of the match algorithm combine to give a 'peak purity'!


Courtesy of Agilent

Part of the 'purity' algorithm!

Leading to powerful probability-based matching (PBM).


Courtesy of Perkin-Elmer


Courtesy of LC Chromatography Online

Caffeine in a carbonated drink confirmed by retention time and spectral match.