Batch analysis: What’s the largest number of samples you can analyze? Not 1, not 2, not 3…
Anyone that’s worked with GPC/SEC knows there’s plenty of trial and error involved before you land on an effective calculation method. Mobile phase, columns, temperature, flow rate – adjusting those parameters can significantly influence the quality of your chromatography. But sometimes the adjustments come after the data has been acquired. Choosing an appropriate dn/dc value or analysis type can be just as important to obtaining accurate data.
The OMNISEC software contains features that make exploring different analysis possibilities easy and convenient. This post will discuss one such recent addition to the software: batch analysis.
What is batch analysis?
Batch analysis is what it sounds like – a way to apply the same calculation method to process multiple samples simultaneously.
How can batch analysis help me?
If you’ve ever tried to establish a dn/dc value for a new material you’ve developed, or you analyze samples in triplicate, or you want to compare the results of multiple samples with current and historical methods, then batch analysis is a tool for you!
I frequently use batch analysis when running samples for the first time. I’ll make multiple injections of a sample and allow the software to calculate a dn/dc value for each injection based on the input sample concentration and observed RI response. Then I’ll examine the collection of values and choose a representative value. For example, if four injections of a sample produce dn/dc values of 0.095, 0.099, 0.101, and 0.098, I would probably choose 0.100 as a reasonable dn/dc value for that sample.
At that point, I can edit the method to assign 0.100 as the dn/dc value, either by using the Sample type or using the Method (fixed) dn/dc value. Then, I simply use batch analysis to re-analyze all of the injections to apply the updated method.
Can I use batch analysis with automated limits and baselines?
Yes! Please see my post from last month for a detailed explanation of how to do this.
Sounds great! How do I use batch analysis?
It’s easy! First, ensure you have your desired calculation method already created. This can be a saved method you access through the database or one you are creating with a fresh standard for that sequence. It is important to remember that unless you are using automated limits and baselines, you will need to work with injections that already have saved limits and baselines.
Second, highlight all of the sample injections you wish to analyze with this method. You can do this by holding Ctrl and individually clicking on the injections with the left mouse button, holding Shift and using the left mouse button to click the first and last of a series of consecutive injections, or using the left mouse button to click and drag to highlight a range of consecutive injections.
Third, select the calculation method you want to apply from the drop-down menu. You will receive a message asking you to confirm that you do indeed want to re-calculate results of the identified injections.
Once you click Ok, a new window will show the progress until the analyses are complete.
And that’s it! Once the analyses are complete your newly calculated results are ready to view. And your previous results will not be deleted; they are always accessible by clicking the expand icon to the left of the Sample Name.
Final thoughts
In conclusion, I hope this post helps you understand what batch analysis is and how you can use it to speed up your analyses. If you have any questions, please don’t hesitate to contact us or email me directly at kyle.williams@malvernpanalytical.com.
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