Determination of an Iron Suspension in Water by Laser-Induced Breakdown Spectroscopy with Two Sequential Laser Pulses

Abstract

We have applied laser-induced breakdown spectroscopy to quantitative analysis of colloidal and particulate iron in water. A coaxial sample flow apparatus developed in our previous work, which allowed us to control the atmosphere of laser-induced plasma, was used. Using sequential laser pulses from two Q-switched Nd:YAG lasers as excitation sources, the FeO(OH) concentration in the tens of ppb range was determined with an optimum interval between two laser pulses and an optimum delay time of a detector gate from the second pulse. The detection limit of Fe decreased substantially using two sequential laser pulse excitations: the 0.6 ppm limit of single pulse excitation to 16 ppb with sequential pulse excitation. The effects of the second laser pulse on the plasma emission were studied. The concentration of iron in fine particles in boiler water sampled from a commercially operated thermal power plant has been determined successfully by this method. The results show the capability of laser-induced breakdown spectroscopy in determining suspended colloidal and particulate impurities in a simple and quick way.

High repetition rate laser-induced breakdown spectroscopy using acousto-optically gated detection

“…LIBS has been successfully applied for quantitative analysis of trace elements in solids, 5,6 liquids, [7][8][9] and gases. 10,11 Numerous experimental setups have been introduced with different laser sources and spectrometer types.…”

Control of a Micro-Droplet for Laser-Induced Breakdown Spectroscopy Solution Measurement

“…LIBS has been investigated extensively to establish a method for the proper chemical analysis of specimens [1]- [3]. Although qualitative analysis results can be performed for a spectrum only by using a wavelength calibration reference, quantitative analysis can be carried out on the basis of several fundamental approaches using conventional methods that require many calibration processes [4,5]. In this study, the measurements are based on fundamental approaches for quantitative analysis (microsecond time-gated spectroscopy) and on the repetitive single spark for averaging the spectra from many shots.…”

Evaluation of the Potential of Laser-Induced Breakdown Spectroscopy for Detection of Trace Element in Liquid

“…[16][17][18][19][20][21][22][23] These works mostly concentrated on demonstrating various techniques that can improve LIBS' sensitivity and precision in liquid. For example, Nakamura et al 18 used a liquid jet system and two excitation lasers to achieve a detection limit for Fe as low as 16 ppb in FeO(OH) in water. Samek et al 19 tested different experimental setups for remote LIBS measurement with a flowing laminar stream of water.…”