Laser-Induced Breakdown Spectroscopy Technique And Its Application In Vegetables Elementals Analysis

Laser-induced breakdown spectroscopy is a technique which analyzes the emission spectra of atoms and ions in plasma caused of a strong laser beam through the lens focused on the sample surface.In this paper, we attempted to apply this technology on the experiment which detected the elements of vegetables primarily. We used nanosecond laser as light source, with the center wavelength of 1064 nm, repetition rate 10 Hz and pulse width 10 ns. The focal length of focusing lens is 3.5 cm. We made laser ablation on cabbage, rape, spinach to produce the plasma on the surface. Then we collect excited emission spectra of the plasma through the collection lens, sent through the probe to Intensified Charge-coupled Device and spectrometer, and generate spectra figure by a. computer. And through the National Institute of Standards and Technology database we searched the spectrum in order to determine the type of elements contained in vegetables from the experiments. The cabbage contains 10 kinds of elements in all, which are nitrogen elements, oxygen elements, iron elements, phosphor elements, manganese elements, chlorine elements, cuprum elements, carbon elements, sodium elements and calcium elements; rape contains 8 kinds of elements in all, which are nitrogen elements, oxygen elements, iron elements, manganese elements, cuprum elements, calcium elements, sodium elements and phosphor elements; spinach contains 10 kinds of elements in all, which are nitrogen elements, iron elements, oxygen elements, manganese elements, calcium elements, phosphor elements, sodium elements, chlorine elements, cuprum elements and aluminum elements. These elements are the essential elements of vegetables. Then we changed the external environment of the above three kinds of vegetables (they were dealt with different pesticides), made experiment analysis on the processed vegetables using laser induced breakdown spectroscopy in exactly the same conditions as above, and interpret the results of its analysis with Applied Spectroscopy knowledge learned.Finally, we also discussed the feasibility of quantitative analysis of the contents of elements in vegetables and summarized the problems and the lack in the experiment for further in-depth analysis in the future.