SMA is an open architecture to analyze simple mixtures by NMR. It relies on available discrete peaks per constituent
All you need to start is to develop and validate a method using 1D or 2D experiments. Once you define your integration regions, these are converted into relevant concentrations using a suitable mathematical expression. This conversion of extracted experimental integral to quantitative results is under your full control. You can use different quantification methods such as molar ratio, simple concentration or purity determinations required for your mixtures analysis.
- The standard equations for each case are shown in this article.
- If you have not installed the SMA plugin yet you can have a look at our installation guide.
- This guide will show you a worked example to get you started using SMA. You can find a step-by-step procedure and a dataset file for a different case scenario in the SMA manual.
Worked example: Brucine spiked with diethyl ether
Since we are calculating mole% or weight% of solvent, relative to the main component, sample-specific data is not required in this case.
You just need to call up the Mnova experiment (brucine with ether in this case) and open the SMA plugin located in the Mnova menu “Advanced/ Simple Mixture Analysis”:
In general you can run any number of experiments and organize them in libraries which are simply specified files folders containing experiments (.EXP files).
In this particular case you can access to the library “brucine with residual solvents” in the following zip_file or alternatively create your experiments and equations manually.
You can share your validated libraries with other users by copying them into a library folder.
The following tutorial shows you how to create your own compound library from scratch.
The SMA panel displays at the top the main three buttons “Analysis”, ”Settings” and “Libraries” and also the Analysis Data and Results tabs:
You can open your libraries, add your quantification parameters and also edit your experiment.
The “Editing Experiment” button will take you to a separated window where you can specify your mixture componen’s details such as units, molecular weight, compound type, specify your multiplet ranges, integration mode, color set up, etc. as shown in the picture below:
For Et2O the formula editor displays a simple molar ratio equation of ether (I1/NN1) and ether + brucine (I1/NN1+ IR1/NNR1):
Once you have entered all your required data, before you press the “Analysis” button you can select your preferred results settings by clicking on the “Settings” button:
Check for any discrepancies in your results:
Once you press the “Analysis” button your results and a notification with any inconsistencies “Alerts” will be displayed will be displayed as follows:
Remember to look for any warning messages in the “Alerts” tab and apply any manual changes, as required:
You can interact with your Mnova database to import spectral ranges, molecular weight and number of nuclides.
For overlapping peaks you can use the Peak Pattern Recognition functionality.The idea is to start with a spectrum having a multiplet pattern defined. SMA can be asked to search for that pattern rather than use the usual multiplets/ integral regions. This technique is best suited to overlapping peaks.
Summarizing, we have designed a versatile, functional program for the quantitation of simple mixture components by NMR. You can use a flexible equation editor to have access to integrations from one or more 1D or 2D spectra, and thereby design an analysis. Multiplets can be automatically checked and the analysis adjusted manually. Reporting can be fully customized.
You can read further information and look up another example of quantification (aloe vera example) in the SMA Manual.