Microplastic Spectral Classification Needs an Open Source Community: Open Specy to the Rescue!

Microplastic pollution research has
suffered from inadequate data
and tools for spectral (Raman and infrared) classification. Spectral
matching tools often are not accurate for microplastics identification
and are cost-prohibitive. Lack of accuracy stems from the diversity
of microplastic pollutants, which are not represented in spectral
libraries. Here, we propose a viable software solution: Open Specy.
Open Specy is on the web (www.openspecy.org) and in an R package. Open Specy is free and allows users to view,
process, identify, and share their spectra to a community library.
Users can upload and process their spectra using smoothing (Savitzky–Golay
filter) and polynomial baseline correction techniques (IModPolyFit).
The processed spectrum can be downloaded to be used in other applications
or identified using an onboard reference library and correlation-based
matching criteria. Open Specy’s data sharing and session log
features ensure reproducible results. Open Specy houses a growing
library of reference spectra, which increasingly represents the diversity
of microplastics as a contaminant suite. We compared the functionality
and accuracy of Open Specy for microplastic identification to commonly
used spectral analysis software. We found that Open Specy was the
only open source software and the only software with a community library,
and Open Specy had comparable accuracy to popular software (OMNIC
Picta and KnowItAll). Future developments will enhance spectral identification
accuracy as the reference library and functionality grows through
community-contributed spectra and community-developed code. Open Specy
can also be used for applications beyond microplastic analysis. Open
Specy’s source code is open source (CC-BY-4.0, attribution
only) (https://github.com/wincowgerDEV/OpenSpecy).