Combination of an intensified charge coupled device with an echelle spectrograph for analysis of colloidal material by laser-induced plasma spectroscopy

An evaluation of the adaptation of an echelle spectrograph to an intensified charge coupled device (ICCD) for Laser-induced Plasma Spectroscopy (LIPS) analysis of environmentally relevant heavy metal hydrocolloids deposited on a membrane filter is presented. For artificial and natural colloids we could demonstrate that an echelle spectrograph with an ICCD allows a spectral resolution and enlarged spectral coverage superior to a conventional LIPS detector system based on a Czerny-Turner spectrograph and an intensified diode-array. Especially natural samples were not accessible with the conventional system, while the echelle system permitted an unequivocal multivariate identification of a set of emission lines from a large set of individual elements. For different heavy metal hydrocolloids we could verify that no significant difference in terms of limit of detection exists between the echelle/ICCD system and the conventional system. In addition, we illustrated for Al2O3 colloids the utilization of the echelle spectrograph for plasma diagnostics, which can be important for normalization in case of variable plasma conditions and self-absorption. (C) 1998 Elsevier Science B.V. All rights reserved.