Table 3.

Main features provided by the most common detectors coupled online with FFF techniques.

Detector	Features
UV-Vis/DAD	Spectroscopical Characterization Concentration detector Studies on evolving system (drug loading and releasing, conjugations…) Versatile signal (a specific)
FLD	Spectroscopical Characterization Studies on evolving system (drug loading and releasing, conjugations…) Very selective signal (quite specific) Stable signal less prone to drifts and interference
dRI	Concentration detector Unstable signal significantly affected by pressure changes Universal signal
MALS	Requires concentration signal Accurate determination of molecular weight/molar mass, radius of gyration (Rg) and fractal radius (δ) Information on the aggregation rate of nanosystems Information of the shape of nanoparticles (conformation plot) Working size range(1 nm–100 μm)
DLS	Determination of hydrodynamic radius (Rh) Estimation of the shape factor (Rg/Rh) Working size range(1 nm–100 μm)
ICP-MS	Studies on evolving system by monitoring elemental composition Low detection limit (ng/L)
High-Resolution MS	Accurate information on molar mass of molecules and complex Evaluation of loading processes inside nanosystems (e.g., Liposomal carriers)