Trace Element Analysis Techniques in Environmental Samples

Trace element analysis in environmental samples underpins assessments of ecological health, pollution trends and resource exploration. Environmental matrices such as water, soil, sediment and biota present complex matrices with low concentrations of metals and metalloids, demanding sensitive and selective analytical approaches. Sample preparation methods—including liquid–liquid microextraction, solid-phase extraction and novel sorbent materials—enable preconcentration and matrix removal prior to instrumental measurement. High-throughput techniques based on inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS) and flame atomic absorption spectrometry (FAAS) deliver elemental quantification at parts-per-billion levels. Innovations in extraction chemistry, such as tailored chelating agents, ionic liquids and functionalised nanoparticles, have enhanced enrichment factors and reduced solvent consumption. Emerging strategies integrate miniaturised extraction formats with portable detectors to facilitate in‐field monitoring. The global significance of such methods is evident in water quality surveillance, soil contamination mapping and assessment of trace metals in food chains. Recent advances aim to improve accuracy, reduce analysis time and extend applicability to diverse environmental compartments while meeting increasingly stringent regulatory limits.

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Research from all publishers

Recent studies have demonstrated substantial advances in preconcentration and detection of trace metals. An ion-association dispersive liquid–liquid microextraction method was developed for gold in aqueous samples using a quaternary ammonium extractant and small volumes of 1-octanol and acetonitrile, followed by ICP-OES measurement. This approach achieved detection limits below 0.1 ng mL–1, enrichment factors exceeding 150 and high precision in tap, lake and mining waters. A solid-phase extraction technique employing γ-alumina nanoparticles functionalised with 9-acridinylamine has been used to concentrate gold from wastewater and soil extracts prior to FAAS analysis. Optimised elution conditions at acidic pH yielded recoveries above 98 % and detection limits near 13 ppb, illustrating the potential of tailored nanomaterials for routine monitoring. Complementing metal-specific approaches, a dispersive liquid–liquid microextraction protocol for palladium employed 2,2′-furyldioxime as a chelating agent with chloroform as the extractant solvent, delivering preconcentration factors up to 250 and detection limits of 0.04 µg L–1 by FAAS. These diverse methodologies underscore ongoing efforts to refine extraction chemistries and instrumentation integration, advancing trace element determination in complex environmental matrices.

Trace Element Analysis Techniques in Environmental Samples publication trend

The graph below shows the total number of articles in trace element analysis techniques in environmental samples across all publications each year (not limited to Nature Index journals).

Technical terms

Trace element: A chemical element present at very low concentrations (typically µg L–1 or ng g–1) in environmental samples.

Dispersive liquid–liquid microextraction: A miniaturised preconcentration technique in which a small volume of extraction solvent is dispersed in an aqueous sample by a disperser solvent, facilitating rapid analyte transfer.

Solid-phase extraction: A sample preparation method that isolates and concentrates analytes by sorption onto a solid sorbent, followed by elution with a suitable solvent.

Inductively coupled plasma optical emission spectrometry: An analytical technique that atomises and excites elements in a plasma source, measuring characteristic emission lines for quantification.

Flame atomic absorption spectrometry: A detection method in which a sample introduced into a flame produces ground-state atoms that absorb light at element-specific wavelengths.

Preconcentration factor: The ratio of analyte concentration in the extract to its original concentration in the sample, indicating the degree of enrichment.

Limit of detection: The lowest concentration of an analyte that can be reliably distinguished from background noise, typically defined at a specific signal-to-noise ratio.

References

1. Ion-association dispersive liquid–liquid microextraction of ultra-trace amount of gold in water samples using Aliquat 336 prior to inductively coupled plasma atomic emission spectrometry determination. Journal of Analytical Science and Technology (2016).
2. Dispersive liquid-liquid microextraction procedure for the determination of palladium by flame atomic absorption spectroscopy. Journal of the Brazilian Chemical Society (2012).
3. Flame Atomic Absorption Determination of Gold Ion in Aqueous Samples after Preconcentration Using 9‐Acridinylamine Functionalized γ‐Alumina Nanoparticles. Journal of Chemistry (2013).