Rapid elemental analysis of human teeth using laser induced breakdown spectroscopy

Abstract

Laser induced breakdown spectroscopy has now become a promising tool for quick analysis and characterization of broad range of physical and biological samples. In this study we have reported elemental analysis of the human teeth using laser induced breakdown spectroscopy technique. The fundamental (λ = 1064 nm) and the second harmonic generation (λ = 532 nm) of Nd: YAG laser were used to ablate the samples of human teeth in air at atmospheric pressure. In the recorded spectrum of the teeth plasma we detected the Hydrogen (H), Carbon (C), Oxygen (O) and Nitrogen (N) as well as trace amount of Calcium (Ca), Iron (Fe), Mg (Magnesium), Sulfur (S), Zinc (Zn) and Ni (Nickel) elements. Also Chromium (Cr) from transition [3d4(5D) 4s4p (1P0) (y5 D02) → 3d144s2 (a5D3] at wavelength 300.5 nm. From the spectroscopic analysis of the transition lines of the calcium we measured the electron temperature using the intensity ratio of the transition lines [3p64s4d (3D3) → 3p64s4p (3P02)] at 445.4 nm and 3p64s3s (3S1) → 3p64s4p(3P02) at 616.2 nm. The intensities ratios CaII/CaI and MgII/MgI were used for quantitative determination of hardness. and the electron number density was measured from Stark broadening of transition [3p64s4d (3D3) → 3p64s4p (3P02)] at 422.6 nm under the assumption of local thermodynamic equilibrium. The density of calcium and phosphorous, which are the main matrix of teeth was thus estimated from intensity ratios and electron number density and compared with standard values.