Nanoparticle Characterization and Separation Techniques

Nanoparticles exhibit unique chemical and physical properties that underpin their widespread use in medicine, electronics, environmental remediation and consumer products. To harness these capabilities safely and effectively, researchers employ a combination of separation and characterisation methodologies. Separation techniques such as field-flow fractionation, hydrodynamic chromatography and capillary electrophoresis enable the isolation of particles according to size, density or surface chemistry. Once separated, nanoparticles are interrogated by complementary detection methods including dynamic light scattering, multi-angle light scattering, inductively coupled plasma mass spectrometry and electron microscopy. This multi-modal approach yields detailed information on particle size distributions (number-based and mass-based), shape, surface charge and elemental composition. In parallel, sample preparation strategies—ranging from acid digestion and ultrafiltration to cloud-point extraction—ensure that particles are released intact from complex matrices such as foodstuffs, environmental waters or biological fluids. Together, these separation and characterisation tools support regulatory compliance, quality control and risk assessment, while driving innovations in nanomaterial design and application.

Research from Nature Portfolio

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Research from all publishers

Advances in asymmetric flow field-flow fractionation coupled with inductively coupled plasma mass spectrometry (AF4-ICP-MS) now permit simultaneous fractionation and elemental quantification of metallic and metal-oxide nanoparticles in consumer products and complex food matrices. This approach delivers high-resolution size distributions and number-based metrics, overcoming challenges associated with polydispersity and matrix interferences. Hydrodynamic chromatography paired online with UV-visible, fluorescence and ICP-MS detectors has been validated for sizing and quantification of inorganic colloids in environmental samples. By distinguishing organic and inorganic fractions in real-world waters and sunscreens, this method demonstrates flexibility, sensitivity and resilience against high organic backgrounds. More recently, capillary electrophoresis (CE) has emerged as a rapid, cost-effective alternative for separating non-spherical and polydisperse nanomaterials. When combined with mass spectrometry, CE-MS reveals detailed compositions of the nanoparticle corona, including low-abundance proteins and small molecule ligands, thereby offering new insights into surface-mediated interactions in biological and environmental contexts.

Nanoparticle Characterization and Separation Techniques publication trend

The graph below shows the total number of articles in nanoparticle characterization and separation techniques across all publications each year (not limited to Nature Index journals).

Technical terms

Asymmetric flow field-flow fractionation (AF4): A separation technique that uses a cross-flow field perpendicular to channel flow to fractionate particles by size or diffusion coefficient.

Hydrodynamic chromatography (HDC): A column-based method that separates colloidal particles by size through differences in flow path within a particle-permeable packing or capillary.

Capillary electrophoresis (CE): An electrokinetic separation technique in which charged nanoparticles migrate through a narrow capillary under an applied voltage, resolving species by charge‐to‐size ratio.

Inductively coupled plasma mass spectrometry (ICP-MS): A sensitive elemental analysis method in which nebulised samples are ionised in a plasma and measured by mass spectrometry to determine metal content.

Dynamic light scattering (DLS): A photon correlation spectroscopy technique that assesses the hydrodynamic diameter of particles in suspension by analysing fluctuations in scattered light intensity.

References

1. First steps towards a generic sample preparation scheme for inorganic engineered nanoparticles in a complex matrix for detection, characterization, and quantification by asymmetric flow-field flow fractionation coupled to multi-angle light scattering and ICP-MS. Journal of Analytical Atomic Spectrometry (2015).
2. Evaluation of Hydrodynamic Chromatography Coupled with UV-Visible, Fluorescence and Inductively Coupled Plasma Mass Spectrometry Detectors for Sizing and Quantifying Colloids in Environmental Media. PLOS ONE (2014).
3. Size-Selective Separation Techniques for Nanoparticles in Liquid. KONA Powder and Particle Journal (2015).
4. Can cloud point-based enrichment, preservation, and detection methods help to bridge gaps in aquatic nanometrology?. Analytical and Bioanalytical Chemistry (2016).
5. Current Application of Capillary Electrophoresis in Nanomaterial Characterisation and Its Potential to Characterise the Protein and Small Molecule Corona. Nanomaterials (2018).