Characteristics of the Laser-Induced Breakdown Detection of Colloidal Nanoparticles for Determining Particle Size

Laser-induced breakdown detection (LIBD) of colloidal nanoparticles has been investigated in various fields, such as the measurement of natural colloids in drinking water (Bundschuh et al., 2005; Kaegi et al., 2008; Wagner et al., 2005; Walther et al., 2006), the in-situ observation of colloid mediated pollutant transport (Hauser et al., 2002; Mori et al., 2003) and the real-time measurement of the solubility of radioactive elements (Bundschuh et al., 2000; Cho et al., 2008; Knopp et al., 1999; J.I. Kim, 2006; Neck et al., 2001, 2003; Opel et al., 2007; Walther et al., 2007). LIBD is an established technique that measures the size and concentration of colloidal particles in aqueous media using plasma formation, which is induced by focusing a short pulse laser beam into the solution (Kim & Walther, 2007). LIBD is especially efficient for detecting small particles less than 100 nm in diameter, which are not easily detectable using commercially available devices that adopt the measurement of a scattered light intensity, such as photon correlation spectroscopy (PCS) (Bundschuh et al., 2001b). Although several different LIBD systems have been developed over the last decades, a commercial instrument that adopts the LIBD method is currently unavailable.