5 Reasons Labs Use Pyrolysis for Microplastics Analysis

Microplastics has become a hot environmental topic and critical research area for many plastics manufacturers and product consumers. Microplastics are very small pieces of plastic that come from a variety of sources. They can be primary (purposely manufactured), secondary (breakdown of larger plastic debris) or the by-product of wastes and other plastics. Although microplastics are small, their negative impact to the environment is quite large. Recently, they have been recognized as a significant source of environmental pollution, especially in ocean and aquatic life. As analytical scientists and researchers look for reliable and accurate ways to analyze these tiny polymers, more and more people are turning to pyrolysis for microplastics research.

Many analytical laboratories and scientists around the world are seeking new technologies and developments that can analyze these microplastics qualitatively and quantitatively. The analysis of microplastics is critical in many industries, such as food safety, drinking water, and consumer products. In addition, analyzing microplastics in seas and their effects on aquatic life and people who are endogenous to the islands enables scientists to create a social awareness on the pollution.

There are a number of ways microplastics are proving to be harmful to humans and animals. Microplasics accumulate in seafood and other food products that eventually are eaten by humans and end up in the bloodstream. And studies are showing the adverse health impacts for people ranging from chronic inflammation and metabolic disturbances to neurotoxicity and increased cancer risk.

Microplastics can result from the slow breakdown of plastic debris in oceans, including plastic bottles.

One of the primary analytical techniques used for analyzing these microplastics is Pyrolysis-GC/MS. To perform this technique, scientists turn to the Frontier Multi-Mode Pyrolyzer directly interfaced to a GC/MS system. Today, analytical pyrolysis encompasses much more than simple flash pyrolysis of polymeric materials. The Frontier multi-mode pyrolysis system can characterize virtually any material (liquid or solid) in microplastics: volatiles, additives, oligomers, polymeric, and heavier components. Analytical laboratories that have integrated this method into their mainstream analytical protocols enjoy the benefits and immediate quality improvements this technique provides.

Here are the top 5 reasons scientists in environmental laboratories are turning to the Frontier PY-GC/MS instrument, and using pyrolysis for microplastics research:

Reason 1: The Method Map Process

This technique provides scientists with a direction to the destination, which is: analyzing the chemical composition of microplastics in various forms of samples with two simple steps. The first step is the Evolved Gas Analysis (EGA). EGA provides a clear picture of the sample complexity. The sample is dropped into the furnace at a relatively low temperature (40-100˚C). The furnace is then programmed to a much higher temperature (600-800˚C). Compounds “evolve” from the sample as the temperature increases. A plot of detector response versus furnace temperature is obtained. Using the EGA thermogram, one can then identify the thermal zone where specific compounds of interest evolve from the sample and perform multiple analyses (such as Thermal Desorption, Flash Pyrolysis, Double-Shot, Heart-Cutting, Reactive Pyrolysis, etc.). The EGA thermogram enables the user to identify the appropriate temperature zone(s) when programming the Pyrolyzer’s furnace for each step. Determining the right temperature and applying sufficient heat to the sample prevents any over or under heating analysis. [ Learn more about the Method Map process ]

Reason 2: The F-Search Engine Library

Microplastic materials often contain a variety of polymers and additives These compounds might be identified using commercial mass spectral (MS) libraries; however, these general-purpose MS libraries contain very few entries for pyrolyzates and additives. This severely limits their utility for polymer characterization. To improve and simplify data interpretation, F-Search libraries are being used for analyzing the microplastics. The libraries include both chromatographic and mass spectral data. There are four unique libraries which allow users to select among them for specific purposes. The ability to create in-house specialty libraries is incorporated into the standard software. The custom user library enables scientists to perform contamination and comparative analyses on their microplastic samples.

Reason 3: No Need for Solvent Extraction or Sample Pretreatment

Many analytical techniques require multi-step sample preparation prior to chromatographic analysis. These procedures often include solvent extraction, filtration, and concentration. These traditional techniques are cumbersome, time-consuming, and suffer from analyst-to-analyst variability while producing data of limited value. Using the Pyrolysis GC/MS technique, samples are analyzed “as is”. In fact, sample preparation using PY-GC/MS technique is very simple and straightforward; no solvent and no sample pretreatment needed. In other words, the solid and liquid samples can be injected into the Pyrolyzer without any solvent and sample pretreatment like solvent extraction. Eliminating the solvent extraction process enhances the precision of quantitative analysis while virtually preventing sample contamination and improves analytical efficiency. This is a major benefit to using pyrolysis for microplastics analysis.

Reason 4: Green and Thermal Extraction of Additives/Impurities

This technique thermally extracts additives, volatiles, and lighter compounds from the polymeric mixture in the microplastics. The volatile compounds are thermally extracted by dropping the sample into the furnace (EGA provides the appropriate temperature to program the furnace). The volatiles collect at the head of the analytical column and are chromatographically separated. During the GC analysis of the additives/volatiles, the sample is lifted out of the furnace and rests at near ambient. Upon completion of the GC analysis, the GC oven is reset, and the pyrolyzer furnace temperature is raised (the EGA provides the appropriate temperature for the second analysis). The sample is dropped a second time into the furnace for pyrolysis. The Pyrolzates are trapped at the head of the column and subsequently separated. As a result, two sets of analysis can be performed on a single sample for thermally extracting the additives/volatiles from the polymeric and heavier components present in microplastics.

Think about the amount of money a laboratory can save over time with Pyrolysis-GC/MS capability. In addition to enhancing efficiency, saving a user’s time and eliminating solvent costs, laboratories are protecting their scientists from solvent exposure while operating in an environmentally-friendly way.

Reason 5: Only Small Amount of Sample is Needed

Traditional techniques performed by solvent extraction and sample pretreatment prior to the analysis require a significant amount of sample (usually several grams). In contrast, the Pyrolysis-GC/MS technique enables scientists to perform multiple analyses on a single sample using a few micrograms of samples. These sample sizes are particularly suited for microplastics samples. The sample can be easily placed in the Frontier Eco-Cup, then introduced into the GC/MS by the Frontier pyrolyzer for material characterization.

Conclusion

As government and environmental scientists research the effects of microplastics, it is important that they have the analytical tools to perform their analyses accurately and efficiently. For all the reasons listed above (the Method Map, F-Search Engine Library, no need for sample pre-treatment, green and thermal extraction of additives, and only needing a small sample size), more scientists are turning to the Frontier Multi-Mode Pyrolyzer. When directly interfaced to a GC/MS system and integrated into mainstream analysis, the system offers simplified operation and greater analytical capabilities for the modern environmental lab.

References:

1. This technical note was developed by Frontier Laboratories Ltd. 4-16-20 Saikon, Koriyama, Fukushima, 963-8862 JAPAN.
   http://www.frontier-lab.com/.