How can I adapt my HPLC methods in an easy way?

HPLC method development is really important to make sure you're getting the best results when looking at complex samples. It's all about getting the separation of our analytes just right to make sure you´re getting accurate and reproducible results. When it comes to optimization one of the most common and well-known scenarios is downscaling HPLC methods to more modern column dimensions.

But that means you get to change your HPLC method, which can start to feel like a big deal.

How can I modify my method to suit a different column size? How can I adjust the flow rate? How much should I inject? What about the gradient?

And before you've done anything, you already have doubts and want to leave it as it is.  Even if you have the right formulas at hand. Where was the calculator again? Can someone please do the math?

Don’t worry. We´ve all been there. We have a great tool that will help you adapt your methods in a safe, fast, and simple way.

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The time has come to change your analysis!

Let's take it one step at a time and see how simple it is.

You've got an existing method and a suitable column, so let's get started with the KNAUER HPLC method converter! Just type in all the information corresponding to your current analysis. Then, enter the new desired column dimension, i.e., the length, the inner diameter, and the particle size. The KNAUER HPLC method converter will then automatically calculate the appropriate injection volume and the new flow rate.

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On the next page enter the gradient as in your original method and your adjusted gradient will be displayed immediately. That’s it.

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With a little extra effort, you can enter all your peaks, and you'll get a prediction for the retention times for the new method. Then, you should check it again on the HPLC, but you'll already have an idea of where you're heading!

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When we designed our method converter, we were thinking carefully about the customer’s key needs: optimizing the method to save time and resources. The KNAUER HPLC Method Converter is a very simple, effective, and intuitive tool, in a modern design. And it is free!

Modernize your methods to save time and resources!

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But the best part is coming. THE KNAUER HPLC method converter is USP compliant. So what does it mean and why is that important.

When pharma manufacturers analyze their samples, they must follow the pharmacopeia, which is a set of standards that ensures the quality and safety of the products they make. The US Pharmacopeia (USP) 621 guidelines are important because they say what's okay and what's not when changing parameters in a chromatographic method. When it comes to column dimensions and particle size, many USP methods are a bit outdated. So far, most of the chromatographic advances that allow us to analyze samples much quicker could not be used with these methods. The good news is that the USP, the European and Japanese pharmacopeias now allow changes to modernize HPLC methods. Specifically, adjustments in column dimensions and particle size for both isocratic and gradient methods are now allowed. The tricky part is that both parameters need to be in a certain ratio. The KNAUER HPLC method converter is really helpful here because it checks if your column changes are compliant and flags any deviation. If the new column parameters are good to go, start downscaling your method.

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I still want to bring up another topic that is becoming increasingly important in today's world. Modernizing your methods is a great way to boost your productivity. But it´s not just about speed. Going green is key. By shortening column dimensions and consequently reducing run times and flow rates, the consumption of mostly hazardous solvents can be drastically reduced. You'll be amazed at how much of a difference you can make for the environment with your analysis. It's a win-win for efficiency and sustainability.

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All that's left for us to do is to make these changes in our laboratories.

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If you´re looking to make your HPLC method as efficient as possible, download the KNAUER HPLC method  converter.

If you need a hand, our TechNote Implement the new USP 621 changes for higher productivity – greener and faster (U)HPLC methods with modern columns is a great resource.

For further information on this topic, please contact our author:

Dr. Ulrike Krop krop@knauer.net