Chromatography Forum

Hello,

a chromatogram is characterized by its peaks and the retention times whereas each peak is characterized by width, height, asymmetry.

Is there any software available which allows the input of the mentioned values and than subsequently draws a formal chromatogram?

Thank you very much for every hint.

Regards

Florian

"Spotfire", for instance, can visaulize this kind of data.

There are very very few situations where anyone should be considering doing this though. A genuine chromatogram contains a lot more information than retention time, width, height and asymmetry; it contains the real peak-shape (models of asymmetry are only models; there are lots of ways to be asymmetric), flat-toppiness, and the noise. A "chromatogram" rebuilt from a few numbers is an artificial thing that purports to contain more information than it does.

Having said that, you can do it in Excel if you want.

get a copy of the book below for more informations and a "manual" how to do it with Excel, also some templates on CD-ROM

Kuss, Hans -Joachim / Kromidas, Stavros
Quantification in LC and GC
A Practical Guide to Good Chromatographic Data
ISBN: 978-3-527-32301-2

Or e-mail me privately and I'll send you a copy of "chrom-fake.xls" that I use to regenerate figures for our training courses.

There is software available for theoretical modeling, called "DryLab":

http://www.molnar-institut.com/HP/Software/DryLab.php

Sorry, I have not tried it myself, but it appears to be the only software available.

I presume you mean supplying (X,Y) data points where X=time elapsed and Y=amplitude of detector response. You would import them into some graphics program with the X values in one column and Y values in another. While Excel will generate a graph from this, it has inherent limits as to how many data points it can handle, and we typically find that it only accommodates a fraction of all the (X,Y) points in the chromatogram. A scientific graphics program will accommodate them all and will be much more flexible in how you portray and manipulate the graph (coloring the area under a specific peak, etc.), what formats you can save the graph in, etc. A cheap program that accomplishes all of this conveniently is Psi-Plot.

Dear all,

thank you so much for your ideas. Tom's excel application is very convenient for me; I use it for the rough illustration what will happen when %B or pH is changed (in method development reports). Now, I have an appropriate tool for this.

Regards

Florian

There are very very few situations where anyone should be considering doing this though. A genuine chromatogram contains a lot more information than retention time, width, height and asymmetry; it contains the real peak-shape (models of asymmetry are only models; there are lots of ways to be asymmetric), flat-toppiness, and the noise. A "chromatogram" rebuilt from a few numbers is an artificial thing that purports to contain more information than it does.

Having said that, you can do it in Excel if you want.

I agree, a qualitative comparison of peaks is great. But you cannot compare chromatograms statistically without quantitative data.

Getting back to the actual question: does anybody have experiences with using MatLab for (i) logging LC data from different detectors (e.g. UV detector and organic carbon detector) and (ii) for processing the data (i.e. peak fitting)?

Thanks