Which technique is commonly used for characterizing nanoparticles?

Dynamic light scattering (DLS) is a widely used technique for characterizing nanoparticles due to its ability to measure the size distribution and hydrodynamic radius of particles in a colloidal suspension. This method involves shining a laser light on the suspended nanoparticles and analyzing the scattered light. The motion of the particles causes fluctuations in the intensity of the scattered light, which can be correlated with the particle size.

DLS is particularly advantageous for nanoparticles because it provides information about the average size and polydispersity in real-time, making it effective for characterizing materials in solution. The technique is suitable for a wide range of nanoparticle systems, including those used in drug delivery, environmental applications, and materials science.

Gas chromatography is not appropriate for nanoparticles, as it is primarily used for separating and analyzing volatile compounds in gaseous or liquid phases. Nuclear magnetic resonance is more suited for analyzing molecular structures and dynamics rather than directly measuring particle characteristics. Mass spectrometry typically identifies and quantifies chemical compounds but does not provide size or hydrodynamic information about nanoparticles as effectively as dynamic light scattering does.