TY - JOUR
T1 - The effect of multi-component aerosol particles on quantitative laser-induced breakdown spectroscopy
T2 - Consideration of localized matrix effects
AU - Diwakar, P. K.
AU - Jackson, P. B.
AU - Hahn, D. W.
N1 - Funding Information:
This work was supported in part by the National Science Foundation through grant CTS-0317410. The authors express our gratitude to Elisabetta Tognoni for providing an advance copy of her theoretical framework for temperature analysis, to Prof. Kay Niemax for useful feedback and discussions regarding their recent findings presented at the European Workshop on Laser Ablation, to Prof. Detlef Gunther for sharing his insight on the roles of analyte transport in LA-ICP-MS, and to Prof. Nico Omenetto for assistance with the optical density calculations.
PY - 2007/12
Y1 - 2007/12
N2 - Spectral measurements were performed in a laser-induced plasma to assess the changes in sodium or magnesium analyte emission response from particle-derived sources with the addition of concomitant mass to the aerosol particles. Temporally resolved measurements revealed up to a 50% enhancement in analyte emission with the addition of the elements copper, zinc or tungsten at mass ratios from 1:9 to 1:19, although the enhancement generally diminished by delay times of 60 μs. Additional measurements in magnesium-cadmium aerosol particles were performed to assess the temporal profile of plasma temperature in the spatial vicinity of the aerosol particles using the ion-to-neutral emission ratios. These measurements revealed a general increase in localized plasma temperature with increasing delay time, which is attributed with an initial suppression of plasma temperature about the aerosol particles as plasma energy is required to vaporize and ionize the aerosol particle mass. These measurements provide direct evidence of a matrix effect for aerosol particles, which is attributed primarily to perturbations in the localized plasma properties. These perturbations are minimized at longer plasma delay times; hence quantitative LIBS analysis of aerosol particles should be performed with careful attention given to the temporal plasma evolution. The data further elucidate the complex interactions between the plasma gas and the aerosol particles, during which the finite time-scales of particle dissociation, and heat and mass transfer are equally important.
AB - Spectral measurements were performed in a laser-induced plasma to assess the changes in sodium or magnesium analyte emission response from particle-derived sources with the addition of concomitant mass to the aerosol particles. Temporally resolved measurements revealed up to a 50% enhancement in analyte emission with the addition of the elements copper, zinc or tungsten at mass ratios from 1:9 to 1:19, although the enhancement generally diminished by delay times of 60 μs. Additional measurements in magnesium-cadmium aerosol particles were performed to assess the temporal profile of plasma temperature in the spatial vicinity of the aerosol particles using the ion-to-neutral emission ratios. These measurements revealed a general increase in localized plasma temperature with increasing delay time, which is attributed with an initial suppression of plasma temperature about the aerosol particles as plasma energy is required to vaporize and ionize the aerosol particle mass. These measurements provide direct evidence of a matrix effect for aerosol particles, which is attributed primarily to perturbations in the localized plasma properties. These perturbations are minimized at longer plasma delay times; hence quantitative LIBS analysis of aerosol particles should be performed with careful attention given to the temporal plasma evolution. The data further elucidate the complex interactions between the plasma gas and the aerosol particles, during which the finite time-scales of particle dissociation, and heat and mass transfer are equally important.
KW - Aerosol analysis
KW - Fractionation
KW - Laser-induced plasma spectroscopy
KW - LIBS
KW - Matrix effects
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U2 - 10.1016/j.sab.2007.10.001
DO - 10.1016/j.sab.2007.10.001
M3 - Article
AN - SCOPUS:36749098530
VL - 62
SP - 1466
EP - 1474
JO - Spectrochimica Acta, Part B: Atomic Spectroscopy
JF - Spectrochimica Acta, Part B: Atomic Spectroscopy
SN - 0584-8547
IS - 12
ER -