Quantitative Analysis of Heavy Metals in Water Based on LIBS with an Automatic Device for Sample Preparation

Abstract

Heavy metals in water can be deposited on graphite flakes, which can be used as an enrichment method for laser-induced breakdown spectroscopy (LIBS) and is studied in this paper. The graphite samples were prepared with an automatic device, which was composed of a loading and unloading module, a quantitatively adding solution module, a rapid heating and drying module and a precise rotating module. The experimental results showed that the sample preparation methods had no significant effect on sample distribution and the LIBS signal accumulated in 20 pulses was stable and repeatable. With an increasing amount of the sample solution on the graphite flake, the peak intensity at Cu I 324.75 nm accorded with the exponential function with a correlation coefficient of 0.9963 and the background intensity remained unchanged. The limit of detection (LOD) was calculated through linear fitting of the peak intensity versus the concentration. The LOD decreased rapidly with an increasing amount of sample solution until the amount exceeded 20 mL and the correlation coefficient of exponential function fitting was 0.991. The LOD of Pb, Ni, Cd, Cr and Zn after evaporating different amounts of sample solution on the graphite flakes was measured and the variation tendency of their LOD with sample solution amounts was similar to the tendency for Cu. The experimental data and conclusions could provide a reference for automatic sample preparation and heavy metal in situ detection.

Calibration curve and support vector regression methods applied for quantification of cement raw meal using laser-induced breakdown spectroscopy

“…ξ i and i * x are the relaxation variables that represent upper and lower training errors, respectively. The minimization objective function can be converted to equation (8), by introducing the Lagrange coefficients α i , i * a…”

“…Laser-induced breakdown spectroscopy (LIBS) is an atomic emission spectroscopy technique that can be used for quantitative and qualitative analysis of solid, liquid, gas, and aerosol samples [6][7][8][9][10], with simple or no sample preparation and rapid non-destructive multi-element analysis [11]. Many scholars have used LIBS technology to quantitatively study cement or cement raw materials.…”

Detection of heavy metals in water samples by laser-induced breakdown spectroscopy combined with annular groove graphite flakes

“…The plasma is then analyzed by a spectrometer. Each element has a unique spectral signature that allows its identification [2].…”

A Rising Force for the World-Wide Development of Laser-Induced Breakdown Spectroscopy

“…Among the 31 papers, only 4 were working on the fundamentals [8−11] , 3 on instrumentation [12−14] , and all others [15−38] on applications in different fields. Among these application papers, all the important domains of LIBS application developed in China with a potential large scale market were reported, including coal thermal power plant [15,16] , steel industry or metallurgy [17−22] , construction material production [13] , nuclear industry [23−24] , and environmental [25,26] . Compared with the first thematic issue, in which only the application coal thermal power plant [39,40] , metallurgy [41] , and national security [42] were involved, there were more research topics explored, such as agriculture [27,28] , and under water applications [29] .…”

“…Compared with the first thematic issue, in which only the application coal thermal power plant [39,40] , metallurgy [41] , and national security [42] were involved, there were more research topics explored, such as agriculture [27,28] , and under water applications [29] . In addition, among these applications, there were many quantitative applications [8,14,16,17,26,32,35,38] .…”