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

Abstract

The use of laser-induced breakdown spectroscopy (LIBS) for the analysis of heavy metals in water samples is investigated. Some factors such as splashing, surface ripples, extinction of emitted intensity, and a shorter plasma lifetime will influence the results if the water sample is directly measured. In order to avoid these disadvantages and the 'coffee-ring effect', hydrophilic graphite flakes with annular grooves were used for the first time to enrich and concentrate heavy metals in water samples before being analyzed by LIBS. The proposed method and procedure have been evaluated to concentrate and analyze cadmium, chromium, copper, nickel, lead, and zinc in a water sample. The correlation coefficients were all above 0.99. The detection limits of 0.029, 0.087, 0.012, 0.083, 0.125, and 0.049 mg l −1 for Cd, Cr, Cu, Ni, Pb, and Zn, respectively, were obtained in samples prepared in a laboratory. With this structure, the heavy metals homogeneously distribute in the annular groove and the relative standard deviations are all below 6%. This method is very convenient and suitable for online in situ analysis of heavy metals.

Rapid determination of trace cadmium in drinking water using laser-induced breakdown spectroscopy coupled with chelating resin enrichment

“…With the aid of high efficacy of enrichment effect of ECS60, our method has largely improved the LOD of Cd in water, compared with other conventional methods, as showed in Table 2. Although, the LOD of Cd can reach 29 µg/L using graphite groove, the experimental system is more complex at the same time 36 . The experimental results proved that the chelation between resin and heavy metals is much effective than other traditional enrichment methods, and no other equipment is required to participate.…”

A hybrid method combining discharge-assisted laser induced breakdown spectroscopy with wavelet transform for trace elemental analysis in liquid targets

“…In this work, the spiked lubricating oil samples with various metal concentrations (23,31,36,43,50,60,74,91,116, and 148 mg L À1 ) are used for quantitative analysis. Fig.…”

Graphene thin film microextraction and nanoparticle enhancement for fast LIBS metal trace analysis in liquids

“…For example, some works propose to perform the LIBS measurement directly on the surface of the liquid sample, to generate an aerosol or a liquid jet to increase the performance of the technique [2]. On the other hand, some authors propose to convert the liquid matrix into a solid in order to eliminate many of the issues [5][6][7][8].…”