New Method Developed to Detect Ultra-Trace Levels of Lead in Drinking Water

Researchers from Huazhong University of Science and Technology in Wuhan, China, and Beijing Academy of Agriculture and Forestry Sciences have developed a new method for detecting ultra-trace levels of lead in drinking water. The research team's findings were published in the Journal of Analytical Atomic Spectrometry (1).

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Lead is a toxic element that can cause health problems even at low levels of exposure. Laser-induced breakdown spectroscopy (LIBS) is a commonly used method for elemental analysis, but its sensitivity is reduced in the presence of water. The researchers used resin enrichment (RE) combined with LIBS-LIF (laser-induced fluorescence) for ultra-trace lead detection in water. This approach demonstrated good linearity with a determination coefficient of 0.98 in the calibration of lead (Pb) and a detection limit (LOD) of 88 ng/L, an improvement of one order of magnitude compared to resin enrichment combined with LIBS (RE-LIBS) analysis.

RE-LIBS assisted by laser-induced fluorescence (RE-LIBS-LIF) is a novel analytical method for ultra-trace lead detection in water. The method involves preconcentration of lead ions onto a resin column, followed by elution of the enriched sample and measurement using LIBS and laser-induced fluorescence (LIF). The LIBS-LIF system is composed of a pulsed laser, a spectrometer, and a photomultiplier tube. The LIBS technique uses a high-intensity laser pulse to create a plasma on the surface of the enriched sample, which emits characteristic elemental spectra. The LIF technique excites and detects the fluorescence of the excited-state atoms or molecules produced by the LIBS process.

The RE-LIBS-LIF method is an efficient way of detecting trace amounts of lead in drinking water, with potential for use in routine water testing. In the study, the team was able to identify lead in samples at concentrations as low as 88 nanograms per liter, which is equivalent to parts per trillion (ppt) levels. The method is fast, non-invasive, and does not require any sample preparation or pre-concentration, making it a promising approach for monitoring drinking water safety.

Lead contamination in drinking water remains a public health concern, and this new method can help ensure that water is safe to drink. It provides an ultrasensitive and cost-effective technique for detecting lead in water that can be used for routine monitoring and detection of potential sources of lead contamination. Further work is needed to validate the method in real-world scenarios and develop an automated system for lead detection in water.

Reference

(1) Wen, X.; Hu, Z.; Gao, Z.; Zhang, D.; Guo, L.; Ma, S.; Dong, D. Detection of lead in water at ppt levels using resin-enrichment combined with LIBS-LIF. J. Anal. At. Spectrom. 2023, ASAP. DOI: 10.1039/D3JA00057E