Laser‐induced Breakdown Detection (LIBD) for the Highly Sensitive Quantification of Aquatic Colloids. Part II: Experimental Setup of LIBD and Applications

Abstract

AbstractLaser‐induced Breakdown Detection (LIBD) enables the concentration and size of aquatic nano‐particles (colloids), in the range of 10–1000 nm and from about 1 ng/L (ppt) up to some mg/L (ppm), to be determined. Such particles, which are frequently encountered in aquatic systems, cannot be detected using methods based on laser light scattering or obscuration or if detection is possible, then only at a comparably low level of accuracy.The method of Laser‐induced Breakdown Detection uses a high‐energy pulsed laser beam to selectively generate a plasma (dielectric breakdown) on particles. The method is based on non‐linear optics and allows for the determination of both mean particle size and concentration in aqueous samples. Practically, this method is non‐invasive, sample preparation is not required, and measurement can take place online.This second part of the double publication describes the experimental basics as well as the latest developments in the field of LIBD. Furthermore, it shows examples of practical applications and compares the technology to standard methods like dynamic laser light scattering as well as laser light obscuration.