Optical Photothermal Infrared spectroscopy (O-PTIR) on the mIRage and mIRage-LS accurately measure and chemically identify particles and micro-plastics from sub-micron to mm’s in size, overcoming the limitations of conventional FTIR and Raman techniques.

Automated, rapid, sub-micron IR and chemical identification of particles and microplastics

Brightfield visible image

featurefindIR particle map highlights particles based on user selection criteria

μChemID database output provides comprehensive analysis of microplastics size and chemical ID

Stacked representative, IR spectra across a wide range of typical microplastics and across a wide range of particle sizes, spanning the challenging <30μm range. Of note is that even particles of 3μm and 30μm from the same material show virtually identical IR spectra

Automated measurement and chemical ID of microplastics from sub-micron to millimeters

Automated measurement and chemical ID of microplastics from sub-micron to millimeters

Measures large numbers of microplastics and particles

Automatic search and selection of particles

Automatic measurement and chemID

Many IR and Raman based applications require the measurement of small particles, often numbering in the hundreds if not thousands of particles. Most notably, such applications include microplastic identification and the characterization of other particles, such as environmental aerosols, pharmaceutical nasal sprays, and organic contaminants.
Optical Photothermal Infrared spectroscopy (O-PTIR) on the mIRage and mIRage-LS accurately measure and chemically identify particles and micro-plastics from sub-micron to mm’s in size, overcoming the limitations of conventional FTIR and Raman techniques.

Automated, rapid, sub-micron IR and chemical identification of particles and microplastics

Detect, select, measure, identify

Particle data collection efficiency

Brightfield visible image

Enhanced contrast cross-polarized visible image

featurefindIR particle map highlights particles based on user selection criteria

Microplastics, particles and organic contaminants can sometimes be difficult to find in a larger population of general contaminants. For maximum flexibility featurefindIR enables use of a variety of image inputs for more accurate and sensitive detection and location including:

Single IR wavelength images.

The use of a cross polarizer (patent pending) for improved contrast for more sensitive and accurate particle detection and location.
Fluorescence imaging for the use of Nile Red (or similar) stains as input images to help locate only the polymeric particles, improving throughput by neglecting non-polymeric particles typically not of interest.
Autofluorescence images can provide for enhanced optical contrast using the intrinsic fluorescence of the samples, without the need for external dyes.

Once the image is captured, tools are provided for accurate selection of the required particles. This is based on size, image intensity of particles of interest as well as adding or deleting particles from the automated selection.

Automatically measure and identify

Once particle locations and sizes are determined, the mIRage system automatically moves to all the measurement locations and performs rapid, automated IR
spectroscopic measurements.
At completion of the measurement a Particle Info summary table lists the positions and certain dimensions of each particle where a key spectrum was acquired. This table can be transferred to the featurefindIR µChemical ID report or exported as a CSV file for external processing in databases such as KnowItAll® shown here.

featurefindIR µChemical ID reporting

μChemID database output provides comprehensive analysis of microplastics size.

μChemID database output provides comprehensive analysis of microplastics size and chemical ID

μChemID database output provides a chemical ID

The featurefindIR µChemical ID report automatically analyzes all user selected spectra within a PTIR Studio file and correlates them against a reference set of spectra in an integrated database. A hit quality index (HQI) is reported back for every measured spectrum. If the HQI is above a user set threshold, the best match chemical ID is also reported. An overlay is displayed between the measured and reference spectra. Color coding is available for visual support in assessing the quantity of spectra with specific plastics types being assigned specific colors as a visual aid. Additionally, quantitative checks can be performed by selecting each result to reveal an overlay of detailed spectra with the closest OPTIR reference match.

Measurement of small <30µm particles

Stacked representative, IR spectra across a wide range of typical microplastics and across a wide range of particle sizes, spanning the challenging <30μm range. Of note is that even particles of 3μm and 30μm from the same material show virtually identical IR spectra

Representative O-PTIR spectra were collected from a range of different polymer particles covering a range of microplastics sizes. These measurements were focused on the smaller range of microplastics, <30µm that are typically beyond the spatial resolution limits of conventional direct IR microscopes (FTIR or QCL).
The figure shows excellent sensitivity and spectral profiles for all polymer types, even demonstrating the collection of virtually identical spectra from 3µm and 20µm PMMA particles.
A feat that traditional IR cannot achieve, not only because of spatial resolution limits but also due to dispersive scatting artefacts which render such traditional techniques sensitive to artefacts from differences in particle morphology (shape and size).