A Time-Gated Raman Spectroscopy and Mass Spectrometry Comparative Chemical Analysis of Plasticizers

Area of Science:

• Analytical Chemistry
• Materials Science
• Polymer Chemistry

Background:

• Quantitative chemical characterization of postconsumer plastics is complex due to diverse polymer chemistries and additives.
• Plasticizers, crucial for polymer flexibility, are difficult to identify and quantify in recycling and end-of-life scenarios.

Purpose of the Study:

• To critically assess mass spectrometry (MS) and time-gated Raman spectroscopy (TG-Raman) for plasticizer identification.
• To generate searchable spectral libraries for 91 common plasticizers.
• To develop tools for measuring spectral similarity and analyzing identification reliability.

Main Methods:

• Generation of searchable spectral libraries for 91 plasticizers using MS and TG-Raman.
• Development of spectral similarity measurement tools.
• Analysis of identification reliability using TG-Raman and liquid chromatography-mass spectrometry (LC-MS).
• Application of developed tools to NIST Standard Reference Material (SRM) 2860 (Phthalates in Polyvinyl Chloride).

Main Results:

• Established searchable libraries for 91 common plasticizers.
• Developed reliable tools for spectral similarity assessment.
• Evaluated the performance of TG-Raman and LC-MS (with atmospheric pressure chemical ionization) for plasticizer identification.
• Highlighted the specific advantages and disadvantages of each technique for different plasticizer chemical families.

Conclusions:

• Both MS and TG-Raman are valuable for plasticizer identification, each with unique strengths.
• The developed libraries and tools enhance the ability to identify and quantify plasticizers in complex plastic matrices.
• This research supports improved chemical characterization of plastics for recycling and waste management.