Another question that quite a few of you asked from the Morphologi G3-ID launch webinar was:
How the instrument uses libraries and what libraries are available?
The answer to the question can really be divided into two sections, the first on how to create and use a library for chemical differentiation, and then secondly how to use third party libraries for chemical identification of unknowns.
Libraries for chemical differentiation
It is a relatively easy task to create libraries from known candidate materials to allow chemical differentiation between particles. This can be done either from a chemical ID measurement of individual particles or from a small reference sample sprinkled onto a quartz slide using the manual microscope interface as shown in the short video below.
The software allows you to use a pre-defined library during an SOP measurement to provide automated chemical ID of the particles, however you can easily realanyse your data after the measurement with a modified or completely different library as many times as you like in order to optimize your chemical ID method.
Libraries for identification of unknowns
In some instances you may wish to identify the chemical composition of a particle that is completely unknown – for example foreign particulate matter. In this case you can either create a library of potential candidate materials yourself – easy to do if you have samples of the suspect materials, or you can export the spectrum to a standard format which can be used by commercially available third party databases.
Exporting the spectrum is very straightforward – you just right click on the spectrum and then choose your data format – either *.csv or *.spc. This spectrum can then be loaded into spectral database search engines such as this online database Ftirsearch.com, which has over 20,000 candidate spectra to search from.
Below shows a search result for a particle spectrum exported from the Morphologi G3-ID shown in red together with the best match from the database shown in blue.
Malvern do not provide a standard database of materials with the instrument as each application will have different requirements and there is no need to duplicate the vast body of work that has already been done in this area.
If you still have more questions regarding libraries don’t hesitate to get in touch!