Automated characterization and identification of microplastics through spectroscopy and chemical imaging in combination with chemometric: Latest developments and future prospects

Numerous studies have been conducted to characterize and identify microplastics (MPs), however, there is a lack of effective standardization and methodologies among different research groups. Automated analysis method based on spectroscopy and chemical imaging techniques in combination with chemometric has developed as a reliable method to enhance the MPs characterization and identification process. Herein, we first review the spectroscopy and chemical imaging methods used for automatic evaluation of MPs, then introduced the workflow of chemometrics, and on this basis, discussed the progress, application, limitations and analytical challenges of the combination of analytical technique and chemometric in the characterization and identification of MPs. Finally, we suggest possible strategies and solutions to push the current detection limits of size and concentration for instrumental detection to a considerably low level.