Detecting and Measuring Free Gadolinium in Nanoparticles for MRI Imaging

This chapter describes a method for the measurement of free gadolinium in nanoparticle samples. Conjugation of a gadolinium-chelate to a nanoparticle allows the particle's distribution to be imaged via magnetic resonance imaging (MRI). Free (unchelated) gadolinium is a known toxin, being a heavy metal, and may contribute towards total gadolinium concentration. Determining the amount of free gadolinium is therefore an important aspect of the preclinical characterization of gadolinium-chelate MRI imaging agent nanoparticles.