%0 Journal Article
%A Meirong Dong
%A Xianglei Mao
%A Jhanis J Gonzalez
%A Jidong Lu
%A Richard E Russo
%B Analytical Chemistry
%D 2013
%N 5
%P 2899 - 2906
%R 10.1021/ac303524d
%T Carbon Isotope Separation and Molecular Formation in Laser-Induced Plasmas by Laser Ablation Molecular Isotopic Spectrometry
%V 85
%8 03/2013
%! Anal. Chem.
%X <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>