Analyte Matrix Excitation Investigations in the High-Voltage Spark Discharge Using an Echelle/CCD System

Abstract

The matrix dependence of analyte excitation in the high-voltage spark discharge has been investigated. The analyte excitation distributions of Fe(I), Mo(I), and Cu(I) have been measured. The large wavelength range of a custom echelle/CCD system was exploited for these determinations. The analyte excitation within the high-voltage spark on a time-integrated basis was determined to be independent of both sample matrix and sampled species.

Nanoparticles in analytical laser and plasma spectroscopy – a review of recent developments in methodology and applications

“…47 The development of the spectroscopic toolbox used for monitoring plasma-based NP generation dates back long before the introduction of the term "nanoparticle". Although in early research the occurrence of microscopic particulates was mostly considered as a side-effect, 48 the accumulated knowledge on material removal from the target, 49 on the excitation of different species, 50 or on the determination of important plasma parameters 51 provided valuable contribution to the plasma spectroscopic monitoring of current NP generation techniques. The application of lasers in monitoring the NP generation opens up further possibilities via selectively exciting particle populations even at different stages of their formation.…”

“…In this case, the temperature is given by the slope of the graph described by eqn (4). 51,82 As it was already noted, Boltzmann plot method relies on the assumption that local thermodynamic equilibrium (LTE)at least partially, for the corresponding transitionsexists. The validity of LTE can be estimated based on the electron concentration from the Griem 83 or McWhirter 84 criteria.…”

“…The validity of LTE can be estimated based on the electron concentration from the Griem 83 or McWhirter 84 criteria. Even though these criteria are widely used to justify the presence of LTE in atmospheric pressure laser-and arc or spark plasmas, 51,69,85 there are indications that a more thorough analysis should be made to assess the validity of the assumption of LTE. 86 When deviation from LTE prevails, the Boltzmann plot method can still be employed to derive the excitation temperature by introducing correction factors.…”

“…86 When deviation from LTE prevails, the Boltzmann plot method can still be employed to derive the excitation temperature by introducing correction factors. 51 Nevertheless, the temperature determined from the Boltzmann plot method describes the temperature of the electrons only when the presence of LTE is justied.…”

“…However, by exploiting the fact that in LTE the population of different ionization stages are determined by T e and n e , one can extend the method to successive ionization stages. The method that incorporates this extension is called the Saha-Boltzmann method, named to refer to the fact that the ionization equilibrium is described by the Saha equation (eqn (5)): 51,69,87…”