Laser-induced breakdown spectroscopy & enrichment by chelation

Abstract

LIBS is used for fast, multi-component analysis of element compositions, but it is not very suitable for liquids. Moreover the sensitivity for metal ions is often insufficient. A fast and sensitive detection tool for metal ions in food matrices, including aqueous solutions, is developed. The principle of operation of LIBS is that a small amount of sample is ablated by an intense laser pulse creating a plasma in which the elements will emit at defined wavelengths. Possible food applications of this technique have been investigated, such as determining the authenticity of food products and the detection of contaminants or health promoting elements. The chelating capacity of three types of chelators immobilized on different surfaces or devices is used for enrichment of metal ions in aqueous media, including saliva, followed by a selective detection with LIBS. The highest sensitivity has been obtained for imino diacetate ligands, resulting in a detection limit for zinc of 0.35 μg. © 2012 The Authors. Published by Elsevier Ltd.