ENVIRONMENTAL LABORATORY


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Using multidimensional electron microscopy in environmental laboratories xxxxx@reply-direct.com


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Multidimensional electron microscopy refers to a family of advanced electron microscopy techniques that extend conventional imaging beyond static, two-dimensional pictures.


Instead of recording only image intensity at each point, these approaches capture additional information across space, energy, reciprocal space, and time.


The result is a much richer dataset that links structure, chemistry, and behaviour within the same experiment.


Traditional TEM or STEM typically produces a 2D projection of a 3D object, with contrast that can be difficult to interpret unambiguously. Multidimensional methods address this by adding new measurement axes. Electron tomography reconstructs full three-dimensional structures by combining images taken at multiple tilt angles.


Spectroscopic techniques such as EDS and EELS add an energy dimension, allowing elemental composition and chemical state to be mapped alongside structure. 4D-STEM goes further by recording a full diffraction pattern at every scan position, combining real-space and reciprocal-space information to quantify strain, crystallography, and internal fields with high precision.


A further dimension is time. In-situ and time- resolved electron microscopy uses specialised holders and detectors to observe samples while they are heated, electrically biased, mechanically stressed, or exposed to reactive gases or liquids.


This makes it possible to watch transformations as they occur, rather than inferring mechanisms from before-and-after images. Increasingly, these dimensions are combined within single experiments, supported by advanced detectors,


high-speed cameras, and data-intensive computational analysis.


Application in environmental labs


The relevance of multidimensional electron microscopy to environmental monitoring lies in its ability to reveal mechanisms that are invisible to field instruments. Air, water, and soil monitoring systems typically measure bulk properties such as concentration, mass, or optical response.


Multidimensional electron microscopy explains what those signals actually represent at the particle or interface level, and how they change over time.


By resolving structure, chemistry, and dynamics together, the technology provides definitive evidence about contaminant form, reactivity, and stability. This supports better sensor design, more defensible proxy measurements, and stronger links between monitoring data and environmental risk.


For monitoring professionals, it functions as a reference tool that underpins interpretation, validation, and forward-looking environmental management rather than a replacement for routine monitoring itself.


Understanding particulate matter at source and in transformation


In air quality monitoring, the most critical uncertainties often relate to particulate matter rather than bulk gas concentrations. Multidimensional electron microscopy allows individual particles to be analysed in terms of structure, composition, and chemical state.


Techniques such as EELS and advanced STEM reveal oxidation states and elemental associations that determine toxicity and


atmospheric reactivity.


Time-resolved and in-situ experiments make it possible to observe how particles age, oxidise, or hydrate after emission, helping explain gaps between emission inventories and ambient measurements.


These insights support air monitoring by improving source attribution, refining sensor calibration, and strengthening links between measured particle metrics and health impacts.


Resolving particle-bound and transformed contaminants


Water monitoring frequently encounters contaminants that are mobile, transformed, or associated with particles rather than present as simple dissolved species.


Multidimensional electron microscopy enables direct characterisation of nanoparticles, colloids, and sediment-bound materials that govern contaminant transport and bioavailability.


By combining spatial and energy dimensions, it becomes possible to identify how metals, nutrients, and emerging pollutants partition between mineral phases and organic matter, particularly at sediment–water interfaces.


In-situ techniques further reveal how these systems respond to changes in pH, salinity, or redox conditions, informing both monitoring strategies and the evaluation of treatment performance.


Linking microstructure, chemistry, and mobility


In soils, key environmental processes occur at the scale of pores, mineral surfaces, and organo-mineral complexes. Electron tomography and spectroscopic mapping allow


Technicians use an electron microscope. Credit: Mykola Vasylechko.


soil microstructure to be reconstructed in three dimensions and chemical forms of nutrients or contaminants to be identified.


This helps explain why some pollutants remain immobilised while others migrate into groundwater or become bioavailable.


Time-resolved microscopy also supports controlled observation of weathering, degradation, and remediation processes, providing mechanistic evidence that complements long-term field monitoring data and improves confidence in risk assessments.


From measurement to mechanism


Across air, water, and soil applications, multidimensional electron microscopy provides ground-truth evidence at the smallest relevant scales.


It explains the mechanisms behind signals detected by sensors and sampling networks, turning environmental monitoring from a largely descriptive activity into a predictive, process- based discipline.


This capability is increasingly important as monitoring frameworks shift toward source attribution, risk-based thresholds, and forward- looking environmental management.


Direct mercury analysis accelerates research and teaching in environmental science


For many academic laboratories, traditional mercury determination techniques remain a bottleneck because they are time consuming, require chemical digestion, and limit the number of samples that can be processed in a teaching or research setting. Inductively coupled plasma techniques, such as ICP- MS and ICP-OES, are adequate for the simultaneous detection of several heavy metals and mass spectrometry (MS) detection can provide excellent sensitivity. Cold Vapour Atomic Absorption Spectrometry (CV-AAS) is also commonly used for mercury analysis and can provide good sensitivity over a wide detection range. However, one of the more significant drawbacks in heavy metals analysis, particularly for mercury, is the extensive sample clean-up required. ICP-MS/ OES and CV-AAS or CV-AFS require solid samples to be digested prior to analysis and CV also requires a wet chemistry reduction to release mercury prior the detection. Since the digestion step is laborious and time- consuming, it isn’t easy to undertake in a traditional teaching environment.


Direct Mercury Analysis (DMA-80) by Milestone offers the most valid alternative, enabling academic labs to conduct fast, accurate mercury determinations without any


sample preparation in solid, liquid, and gaseous matrices. Milestone’s latest system, the DMA- 80 evo, is specifically engineered to support both advanced research and high-throughput academic teaching labs. By eliminating digestion and wet chemistry steps, the DMA-80 evo delivers results in less than six minutes per sample, dramatically improving productivity while ensuring data quality.


Mercury continues to be a central focus in environmental research due to its well-known toxicity and persistence in ecosystems. The technique is based on these four steps: thermal decomposition, catalytic conversion, gold amalgamation, and atomic absorption detection to convert all mercury species to elemental mercury and quantify them with high sensitivity. The system’s double-beam detection technology ensures excellent stability and precision, while the use of air or oxygen as a carrier gas minimises operational costs. A single liquid standard is sufficient for calibration across all matrices, simplifying workflows and ensuring long-term reproducibility.


Considering ease of use, safety and performance, the DMA-80 evo is a optimal solution to colleges and universities looking to enhance their research and teaching capabilities whilst ensuring high level of


safety for the students. Universities across the globe have successfully implemented Direct Mercury Analysis into their research and teaching activities. At Georgia Southern University, thousands of undergraduate students have gained hands-on experience in mercury determination through the analysis of fish, water, and sediment samples. The speed and ease of the DMA-80 evo allows faculty to integrate real-world sample testing into laboratory courses, enhancing student engagement and scientific understanding.


Having published more than 12 research articles involving direct mercury analysis, the Department of Agriculture and Environmental Sciences at Lincoln University acquired a new Milestone DMA-80 evo in 2019 to replace an earlier version of the system that had reliably been in use for 16 years. Purchasing a new instrument was an easy decision based on the many years of instrument reliability, service, and application support provided by Milestone. The new system will address the needs of future research and be utilised as an important teaching tool for students taking the courses Advanced Analytical Methods, Chemical Instrumentations, and Environmental Sampling and Analysis.


The Department of Chemistry at Vassar College was motivated to look for a new


Environmental Laboratory


analytical technique for mercury determination by the increased interest from faculty and students in performing environmental analyses on soils and peat. Although it had an ICP-MS instrument for metals analysis, a dedicated mercury analysis solution was needed to achieve the department’s research goals and throughput needs. The DMA-80 evo Direct Mercury Analyser has allowed students to perform mercury analysis in diverse matrices, including fish and canned products. It has also enabled collaboration between research groups in the Department of Chemistry to support environmental research on soils.


By removing the barriers associated with traditional mercury analysis techniques, such as the use of chemicals and the sample preparation steps, Direct Mercury Analysis empowers faculty, researchers, and students to achieve high-quality results with minimal preparation time and virtually no running costs. As demonstrated across multiple institutions, the DMA-80 evo is a powerful tool for expanding academic research capabilities and enhancing scientific education.


More information online: ilmt.co/PL/ZOGY 66256pr@reply-direct.com


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