@article{25999,
  author = {Meirong Dong and Xianglei Mao and Jhanis J Gonzalez and Jidong Lu and Richard E Russo},
  title = {Carbon Isotope Separation and Molecular Formation in Laser-Induced Plasmas by Laser Ablation Molecular Isotopic Spectrometry},
  abstract = {<p>Laser ablation molecular isotopic spectrometry (LAMIS) recently was reported for rapid isotopic analysis by measuring molecular emission from laser-induced plasmas at atmospheric pressure. This research utilized the LAMIS approach to study C<sub>2</sub> molecular formation from laser ablation of carbon isotopic samples in a neon gas environment at 0.1 MPa. The isotopic shift for the Swan system of the C<sub>2</sub> Δν = 1 band was chosen for carbon isotope analysis. Temporal and spatial resolved measurements of <sup>12</sup>C<sub>2</sub>, <sup>12</sup>C<sup>13</sup>C, and <sup>13</sup>C<sub>2</sub> show that C<sub>2</sub> forms from recombination reactions in the plasma. A theoretical simulation was used to determine the temperature from the molecular bands and to extract the isotopic ratio of <sup>12</sup>C/<sup>13</sup>C derived from <sup>12</sup>C<sub>2</sub>, <sup>12</sup>C<sup>13</sup>C, and <sup>13</sup>C<sub>2</sub>. Our data show that the ratio of <sup>12</sup>C/<sup>13</sup>C varies with time after the laser pulse and with distance above the sample. <sup>12</sup>C/<sup>13</sup>C deviates from the nominal ratio (2:1) at early times and closest to the sample surface. These measurements provide understanding of the chemical processes in the laser plasma and analytical improvement using LAMIS.</p>},
  year = {2013},
  journal = {Analytical Chemistry},
  volume = {85},
  pages = {2899 - 2906},
  month = {03/2013},
  issn = {0003-2700},
  doi = {10.1021/ac303524d},
}