Environmental analytical chemistry provides the tools to identify, quantify, and monitor pollutants. It encompasses a wide range of analytical techniques aimed at detecting contaminants in various environmental matrices, such as air, water, and soil. This helps to better understand the extent of pollution and develop mitigation strategies.
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This rapidly evolving field is crucial in identifying pollutants that may pose risks to environmental and public health. Techniques such as chromatography, spectroscopy, and mass spectrometry allow for the determination of contaminants even at trace levels.
Data from environmental analysis form the basis for environmental regulations and policies; hence, there is a constant need for improved methods for detecting, quantifying, and understanding the distribution and fate of environmental contaminants.
Driven also by the rise in emerging pollutants such as microplastics and nanomaterials, which are becoming increasingly prevalent in the environment, there has been a growing interest in the development of new and more sensitive analytical methods.
Recent Advances
Advancements in analytical techniques, such as high-resolution mass spectrometry (HRMS), laser-induced breakdown spectroscopy (LIBS), and nuclear magnetic resonance (NMR) spectroscopy, have enabled the analysis of pollutants with enhanced sensitivity and specificity, allowing for the detection at lower concentrations than previously possible.
In particular, HRMS makes it possible to determine emerging contaminants, such as pharmaceuticals and personal care products, that were not traditionally monitored. Moreover, portable analytical devices now facilitate on-site analysis, reducing the need for time-consuming sample transportation to laboratories.
The development of emerging technologies in environmental analytical chemistry is constantly evolving. Examples are novel nanosensors and biosensors for environmental monitoring that can provide real-time or near-real-time detection of pollutants with high accuracy and can be used in environmental assessments.
The advent of two-dimensional gas chromatography (GC×GC) has also expanded the ability to analyze complex mixtures of organic pollutants.
Furthermore, the integration of machine learning algorithms with analytical techniques is enhancing data processing and interpretation, leading to more accurate and efficient analyses.
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Applications and Case Studies
Techniques like atomic absorption spectroscopy (AAS) and inductively coupled plasma optical emission spectroscopy (ICP-OES) can be used to determine the presence of heavy metals in soil.
ICP-OES can be used to analyze trace elements. It has a broad linear dynamic range and the ability to examine more elements simultaneously with low detection limits.
In particular, the analysis of soil samples in the Rampal area (Bangladesh) allowed us to identify heavy metals such as Cr, Fe, Mg, Mn, Ni, and Pb, highlighting areas potentially contaminated with Pb due to pollution caused by mining activity and vehicle exhausts.2
The increasing use of non-steroidal anti-inflammatory drugs (NSAIDs) has started to become a threat to the environment, with trace amounts being detected in soils as well as surface and ground natural water.
A new porous material based on silica coated with a dendrimeric copolymer was found to be able to isolate NSAIDs from water samples. Followed by HPLC separation, this approach allowed the detection of traces of ibuprofen and diclofenac in the Vistula river (Poland).3
Compounds such as CO2 and volatile organic compounds (VOCs) like phenol, toluene, and 2-ethyl-1-hexanol may be used as markers for air quality monitoring.
The analysis of VOCs using headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to assess indoor air contamination in sports centers. Besides phenol, the analysis revealed the presence of terpenes commonly found in cleaning products.4
Nitrite, nitrate, and phosphate are important nutrients in aquatic ecosystems, but increased levels can have detrimental effects on public health and the environment.
A simple portable colorimetric method has been developed for the on-site determination of nutrients in water, with good performance and detection limits of 0.02 mgL-1 for nitrite, 0.04 mgL-1 for nitrate, and 0.14 mgL-1 for phosphate.5
These advances have significant implications for environmental policy and public health. Enhanced detection capabilities provide more comprehensive data that inform regulatory decisions, leading to improved pollution control measures.
Challenges and Limitations
A major challenge in environmental analytical chemistry is achieving the high sensitivity and specificity required to detect low concentrations of pollutants within complex environmental matrices. Therefore, advanced techniques, such as high-resolution mass spectrometers and advanced chromatographs, are needed.
For instance, with the use of tandem MS and a triple quadrupole mass detector (QqQ), it is possible to achieve very good specificity and detect analytes on the low picogram scale. However, this normally involves sophisticated instrumentation and highly trained personnel, making these techniques more costly.1
In addition, the vast amounts of data generated by advanced analytical techniques pose challenges in interpretation and require robust data processing.
There is also a growing need to develop reference materials and quality control measures to ensure the reliability of analytical results, especially for emerging contaminants.
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Future Directions
The use of hyphenated techniques can enhance pollutant detection, allowing for the analysis of trace levels even in complex matrices.
The hyphenation of ion mobility separation (IMS) with HRMS has become more prevalent in environmental analysis and has led to the development of novel analytical strategies, particularly in the screening of organic micropollutants.6
Collaborations across disciplines can facilitate the development of new analytical methods and are likely to drive further advancements in the field.
Examples include the combination of chemical detection with biological assessments, providing a more comprehensive understanding of environmental health, or improving environmental risk assessment, especially for emerging contaminants.
Conclusion
Advances in environmental analytical chemistry have greatly enhanced the ability to monitor pollutants, providing valuable insights for environmental assessments and regulatory decision-making aimed at protecting the environment and public health.
As new contaminants are identified and environmental monitoring becomes increasingly complex, there is a need for more sensitive, accurate, and accessible analytical methods. Therefore, continued innovation in this field is essential.
References
- Dévier, M.-H., Mazellier, P., Aït-Aïssa, S. & Budzinski, H. (2011). New challenges in environmental analytical chemistry: Identification of toxic compounds in complex mixtures. Comptes Rendus Chimie, 14, 766-779.https://doi.org/10.1016/j.crci.2011.04.006. Available: https://www.sciencedirect.com/science/article/pii/S1631074811000749
- Parvez, M. S., Nawshin, S., Sultana, S., Hossain, M. S., Rashid Khan, M. H., Habib, M. A., Nijhum, Z. T. & Khan, R. (2023). Evaluation of Heavy Metal Contamination in Soil Samples around Rampal, Bangladesh. ACS Omega, 8, 15990-15999.10.1021/acsomega.2c07681. Available: https://doi.org/10.1021/acsomega.2c07681
- Ścigalski, P. & Kosobucki, P. (2024). Dendrimer Coated Silica as a Sorbent for Dispersive Solid-Phase Extraction of Select Non-Steroidal Anti-Inflammatory Drugs from Water. Molecules, 29, 380. Available: https://www.mdpi.com/1420-3049/29/2/380
- Szulc, J., Okrasa, M., Ryngajłło, M., Pielech-Przybylska, K. & Gutarowska, B. (2023). Markers of Chemical and Microbiological Contamination of the Air in the Sport Centers. Molecules, 28, 3560. Available: https://www.mdpi.com/1420-3049/28/8/3560
- Wongniramaikul, W., Kleangklao, B., Boonkanon, C., Taweekarn, T., Phatthanawiwat, K., Sriprom, W., Limsakul, W., Towanlong, W., Tipmanee, D. & Choodum, A. (2022). Portable Colorimetric Hydrogel Test Kits and On-Mobile Digital Image Colorimetry for On-Site Determination of Nutrients in Water. Molecules, 27, 7287. Available: https://www.mdpi.com/1420-3049/27/21/7287
- Celma, A., Alygizakis, N., Belova, L., Bijlsma, L., Fabregat-Safont, D., Menger, F. & Gil-Solsona, R. (2024). Ion mobility separation coupled to high-resolution mass spectrometry in environmental analysis – Current state and future potential. Trends in Environmental Analytical Chemistry, 43, e00239.https://doi.org/10.1016/j.teac.2024.e00239. Available: https://www.sciencedirect.com/science/article/pii/S2214158824000151
Further Reading