Chromatogram Generator Tool
How do you achieve the fastest or most qualitative LC separation with only a limited budget to spend on instruments, ovens and columns?
Jeroen Billen and Gert Desmet of the Vrije Universiteit of Brussels developed with Peter Schoenmakers an optimization tool for chromatographers that can help you to a small extent through the credit crunch. And, in the spirit of co-operation within the chromatography community, they are sharing it with you.
Try it, it is free... and it is fun!
Frank van Geel, Chromedia
Screenshot from the Chromatogram Generator
Interview with Jeroen Billen and Gert Desmet,
Vrije Universiteit Brussels, Belgium
With this tool, chromatographers can optimize an existing reference separation, only requiring input of several parameters that are readily available to the experimentalist, such as pressure, temperature, column type and length. Jeroen Billen says: "An important feature in the output of the program is that, apart from the parameters that characterize the quality of a separation, such as plate number, retention time, resolution and peak capacity, chromatograms are generated as well. Any chromatographer with the least bit of experience is familiar with this type of output and can directly make a visual verification whether or not the modified chromatographic conditions will suit the needs."
Chromatographers have a wealth of choice if they want to purchase a new instrument or column type. Should one opt for an instrument equipped with a pump that is able to deliver higher pressures or instead invest in a more standard, lower priced HPLC-instrument that is coupled to a high temperature oven? Billen says: "They like to know what the effects are of pressure and temperature on the required analysis time and separation efficiency. The tool shows the effects of these two different instrument upgrades on a given separation."
"We demonstrated a first version in HTC-10 in Bruges and later in London and asked experienced chromatographers in the audience to estimate the best options. Improving a given separation turned out to be a challenging exercise in some cases, even for the most experienced chromatographers amongst the attendees. But they enjoyed playing and saw that making predictions is harder than it looks."
Who should try it?
"It is not necessary to understand the underlying calculations in order to experiment with the tool. The program input is very simple: it allows for a manipulation of the pressure, temperature, column type, particle size and column length. These are all variables that are readily available to every chromatographer. We encourage al chromatographers of all levels to play with the tool. The only pre-requisite to appreciate the tool is that the user is able to analyse a chromatogram and knows how to interpret the characterization parameters such as analysis time, plate number, isocratic peak capacity and resolution."
It is useful for teaching purposes?
"Anybody teaching chromatography can also use it as an illustrative "gizmo" for his or her students to clarify the effects of different parameters on the separation speed and efficiency. Allowing the students to play with the parameters themselves will give them a better insight on the parameters influencing a chromatographic separation. In general, anybody curious to find out what the different effects of different instrument upgrades are on the goodness of a separation are encouraged to use it. However, it will also help practitioners to understand the effects of parameter changes better. "
What was the most surprising result of the program?
"The tool also accounts for extra column band broadening. This means that axial dispersion coming from the injector, connection tubing and detector are incorporated in the calculation of the efficiency. One of the most striking results when testing the tool was the impact of the contribution these extra-column sources of band broadening can have on the total band broadening of the system. This is especially true for high speed separations, where short columns packed with small particles are used. Extra-column band broadening therefore certainly needs to be accounted for."
Do you have any plans for the future with this tool?
" Yes, one future enhancement is the direct calculation of analysis costs over a certain period. This would however require a more rigorous research into the price people have to pay for their instruments and columns. We are also considering providing an easy-to-use version with a restricted number of changeable parameters for educational purposes, and a Pro-version of the tool in which far more parameters are taken into account, and variables such as tubing length and diameter and injector and detector volumes are added. This would give the experimentalist an initial idea if it would be beneficial to invest in the reduction of the extra-column band broadening and if so, how much in terms of efficiency could be gained. For now, we think this basic version is very useful as a start, and depending on the response, we will come up with upgraded versions."
* You will need Adobe Flash Player installed on your computer to view the animations in this tutorial. We recommend you install the latest version of Flash: if you are attempting to view over a network, please contact your network administrator and request the latest version of Macromedia Flash Player. If you are not accessing via a network then you can update your local version of flash player via this link: http://www.adobe.com/go/getflashplayer. Please note that this links to an external website and, although Flash is a very common browser add-on with few known problems, we do not accept responsibility for any problems the download may cause.