Raman Spectroscopy

Mrphologically directed Raman spectroscopy (MDRS), which combines Raman spectroscopy with automatic static image processing, offers chemical specificity and particle identification. It uses the Malvern Morphologi 4-ID device for in-depth analysis and is used to determine chemical forms, pollutants, and particle morphology in a variety of materials.

Read more: What is Raman Spectroscopy?

Raman spectroscopy offers the high degree of chemical specificity necessary to distinguish between different chemical forms of the same compound and identify constituents in a sample. This method creates a potent high-resolution analytical tool for characterizing particles when combined with automated static picture analysis that can measure particle size and form. Applications for morphologically directed Raman spectroscopy (MDRS) include:

Determining the content and particle morphology of a component in a combination, such as the API particle size in a pharmaceutical formulation, developing generic medications, or studying cement. Population isolation of particle size data through speciation is made possible by the ability to exclude particles based on their composition.

Finding contaminants or anomalous particles in a batch of material that is failing. Knowing the pollutants’ composition can then help identify their source of origin.

Examining unidentified particle samples, like the mineral make-up of geological samples.

Particle classes are created after measurements of the sample material’s particles’ size and shape are taken. The information from the image analysis measurement can then be used to create a morphological description of each identified particle in the form of size and shape distributions. Raman spectroscopy can be used to target particles with specific morphology, such as size range or shape parameters, for chemical analysis if a particular component is of interest. Throughout the image analysis measurement, the exact locations of individual particles on the sample slide are noted. To identify each particle against a spectral library, the instrument can then go back and collect its Raman spectra.

With regards to a variety of organic and inorganic materials, MDRS is very well suited. Metals, extremely dark or black samples, and samples that glow at the wavelength of the laser light employed in this form of research are some sample materials that are unsuitable for this sort of analysis (785 nm).

Advantages

• Possibility of differentiating the particle size distribution in a combination
• Detection of impurities or unusual particles with precision

Considerations

• The size of the particle must be 2 m or greater, and it must scatter in the Raman spectra.
• Not suitable for metallic materials or extremely dark or black materials
• This method does not provide a comprehensive chemical composition analysis.

Fewer counts compared to image analysis