Hockaday Senior’s Research Makes Detecting Microplastics Easier

Madalena Ritz-Meuret hopes her methods will promote awareness, cooperation

Bottles, bags, and other debris — it’s not uncommon nowadays to walk alongside the bank of a river or lake and see piles of trash accumulating. 

As these plastics slowly decompose, they have destructive effects on the environment, gradually transforming once pristine urban oases into makeshift landfills. 

Sights like those inspired research by Hockaday senior Madalena Ritz-Meuret — research that led to a ground-breaking low-cost method for detecting microplastic particles. 

“I noticed that the research around (microplastic pollution) in terrestrial environments had been lagging behind in comparison to aquatic or atmospheric environments,” Ritz-Meuret said. “So, I decided to focus on (soil) for my project.”

Previous methods for detecting microplastics in dirt have been proposed, but often are not publicly accessible, and require costly laboratory equipment and labor-intensive procedures.

However, Ritz-Meuret’s new method can be readily used in educational and daily life settings to raise awareness about plastic pollution. 

“My detection method relies on fluorescent analysis with Nile Red dye,” Ritz-Meuret said. “In this type of analysis, Nile Red binds preferentially to the plastics’ surfaces, making them fluoresce or glow when excited by blue light and viewed under an orange filter lens.”

Ritz-Meuret’s method requires very little investment upfront, around $250 or less, and is simple and portable, ideal for field assessments. The method takes approximately 30 minutes for the soil sample to incubate and a few hours for drying the filter paper. 

More recently, Ritz-Meuret was able to verify that microplastic particles can also be detected in wet samples, bringing the total detection time down to 30 minutes.  

“My technique is most useful when (researchers) are out in the field and want to get a quick and reliable representative view of microplastic pollution in a specific geographic area,” Ritz-Meuret said. “Since it’s inexpensive and easy to handle, it can also be used in large scale citizen projects … it’s an effective way of joining researchers and people in a common cause while informing the public about (microplastic pollution.)”

Ritz-Meuret’s technique was tested thoroughly with soil and lake sediment samples. Her methodology and findings have since been included in Analytical Methods, a lead scientific journal published by the Royal Society of Chemistry. 

As part of her independent study project at Hockaday, and with a grant from the Dallas Environmental Education Initiative, Ritz-Meuret has been further investigating her new methodology in wastewater and will be presenting her findings at the 2025 Dallas Water Conservation Environmental Summit.