Microplastics Detection in Streaming Tap Water with Raman Spectroscopy.

Area of Science:

• Environmental Science
• Analytical Chemistry
• Spectroscopy

Background:

• Microplastic contamination is a global issue affecting drinking water, food, and beverages.
• Identifying small microplastics (<1 mm) typically requires spectroscopic methods like Fourier transform infrared (FTIR) or Raman spectroscopy on extracted particles.
• Direct observation of microplastics in drinking water is challenging due to low biological loads.

Purpose of the Study:

• To demonstrate the feasibility of using Raman spectroscopy for direct microplastic detection in flowing tap water.
• To establish a proof-of-concept for a point-of-entry monitoring system for drinking water.
• To assess the potential for monitoring microplastics in clear surface waters.

Main Methods:

• Applied Raman spectroscopy to observe individual microplastic particles in a custom-made flow cell.
• Tested streaming tap water with added particulate and fluorescent contaminants at 1 L/h.
• Evaluated the compatibility of various tubing materials with microplastic suspensions containing common polymers.

Main Results:

• Successfully observed individual microplastic particles in flowing tap water using Raman spectroscopy.
• Demonstrated the potential for detecting microplastics smaller than 0.1 mm.
• Identified suitable tubing materials for microplastic analysis in water.

Conclusions:

• Direct observation of microplastics in tap water via Raman spectroscopy is achievable.
• This technique offers a promising solution for real-time, point-of-entry monitoring of drinking water quality.
• The method could be extended to monitor microplastics in clear surface waters.