Using Automated Raman Microspectroscopy to Detect Microplastics in Potable Water

Raman micro-spectroscopy is a highly effective method for identifying and classifying cancer cells and tissues. Studies have shown good accuracy in detecting bladder, cervical, and oral cancer compared to standard pathology (1). However, despite being non-invasive and cost-effective, its slow recording time and lack of reproducibility have hindered its clinical adoption (1).

Because it is a relatively inexpensive technique to use, smaller laboratories and companies often employ this technique in research. That was one of the reasons why Oskar Hagelskjaer, CEO and Founder of Microplastic Solution, used it in one of his most recent studies that saw him and his team identify, characterize, and study the microplastic (MP) content in potable water (2). Their study examined 10 different bottled water brands, as well as one tap water sample (2).

In Part 1 of our interview with Hagelskjaer, he discusses the EU Directive 2020/2184 that addresses MP detection in potable water. Hagelskjaer argues that this directive may not account for most of the MPs found in drinking water because it only references particles and MPs in the 20–5000 μm range.

In the second part of our interview with Hagelskjaer, he answers the following questions:

• Automated Raman microspectroscopy played a pivotal role in detecting MPs down to 1 μm. Can you elaborate on why this technique was chosen and how it compares to other methods for MP detection?
• Your study emphasizes the importance of including small MPs in potable water analyses and regulatory frameworks. What challenges do you foresee in implementing such comprehensive standards, and how might they be addressed?
• The use of negative and positive procedural quality control measures was a key aspect of your methodology. Can you explain their importance and share any insights into how these controls impacted the study's findings?

Part 1 of our interview with Hagelskjaer is available here.

References

1. O’Dwyer, K.; Domijan, K.; Dignam, A.; Butler, M.; Hennelly, B. M. Automated Raman Micro-Spectroscopy of Epithelial Cell Nuclei for High-Throughput Classification. Cancers (Basel) 2021, 13 (19), 4767. DOI: 10.3390/cancers13194767
2. Hagelskjaer, O.; Hagelskjaer, F.; Margenat, H.; et al. Majority of Potable Water Microplastics Are Smaller Than the 20 μm EU Methodology Limit for Consumable Water Quality. PLoS Water 2025, 4 (1), e0000250. DOI: 10.1371/journal.pwat.0000250
3. Microplastic Solution, About Us. Microplastic Solution. Available at: https://www.microplasticsolution.com/about-us (accessed 2025-01-31).