報文

 

Application of Laser-Induced Plasma Spectroscopy to the Rapid Screening of Plastics for Heavy Metals

蒋大欣・加納英典・葛谷幹夫
Daxin JIANG, Hidenori KANO, and Mikio KUZUYA


Applicability of laser-induced plasma spectroscopy (LIPS) for rapid screening of plastics for trace heavy metals was studied. For this purpose, the experiment was carried out in air at atmospheric pressure, and the emission characteistics of the plasma produced by a Q-switched Nd:YAG laser, in terms of laser pulse energy and lens-to-sample distance, were investigated using time-resolved spectroscopy to determine the optimum conditions for quantitative analysis. The experimental results showed that time-resolved measurement of a spectrum with a delay time of 0.4 μs after the laser pulse was effective for reducing the background continuum, and the emission intensity was maximized by observing the plasma produced by a defocused laser at the laser energy of 90 mJ. Based on the results, standard polyvinyl chloride plastic samples were analyzed for trace elements of lead, cadmium, mercury, and chromium, and linear calibration curves were obtained with the detection limits of about ten ppm.


Keywords: Laser-induced plasma spectroscopy; Rapid screening of plastics; Air at atmospheric pressure; Heavy metals; Time-resolved spectroscopy



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