DETECTION TECHNOLOGY DEVELOPMENT
Work Package 5
The overall objective is to develop technologies that provide state of the art analytical techniques for micro and nanoplastic containing samples.
Many challenges exist for current analytical instruments for microplastics such as PY-GC-MS, Raman and FTIR. Given our overall aim of developing the technology for a low cost, easy to use, reliable and robust instrument for inline measurements, further development of technology for PY-GC-MS is not targeted in MONPLAS. Instead, given that it is currently unique in providing quantitative information, we will use it at WESSLING and GLSciences to benchmark MONPLAS developments. Both Raman and FTIR based techniques have their own challenges for microplastics. Rapid scanning for Raman will be targeted by IPHT using a patented technology for blood cells where whole areas are not scanned, just individual particles and their surrounding areas. 50 ms exposure time is possible plus 50 ms CCD readout (EMCCDs may be even faster). Bruker will be investigating the application of a new microscope based on quantum cascade laser (QCL) spectroscopy. The QCL technology has the potential to improve measurement times that are a limiting factor in current state-of-the-art analysis methods (using conventional infrared microscopes) by orders of magnitude if a small number of spectral channels can be selected. Following breakthroughs for current instruments, the technology developments will be shifted, if necessary, to focus on solutions for rapid, low cost, reliable and easy to use inline FTIR and Raman analysis of microplastics.
For nanoplastics, two approaches will be used. One, by Aston, is the more conventional approach of the use of photoluminescence (PL) to map excitation-emission maps to particle sizes determined previously by density gradient ultracentrifugation methods. The use of PL excitation-emission maps with specially selected laser diodes and USB spectrometer to detect nanoplastics would then be compatible for a rapid, low cost, reliable and easy to use instrument for inline analysis. Optical absorption measurements of nanoplastic samples through the use of integrated spheres as well as dynamic light scattering methods are contingency plans. The second method applies Raman analysis to captured nanoplastics in proximity to gold nanostructures, in techniques known as Surface Enhanced Raman Scattering, or SERS. Here Aston and QUB will collaborate along with VUB and KTH to develop a LOC based solution to nanoplastic identification and enumeration. For both micro and nanoplastics, water samples will be initially targeted. When suitable sample preparation technologies become available from WP4 then more complex media such as beer, honey and salt will be targeted.