Potential of laser ablation and laser desorption mass spectrometry to characterize organic and inorganic environmental pollutants on dust particles

Abstract

Stainless steel factories are known to release particles into the atmosphere. Such particulate matter contains significant amounts of heavy metals or toxic inorganic compounds and organic pollutants such as, for example, Cr(VI) and polycyclic aromatic hydrocarbons (PAHs). The investigation of Cr(VI) and PAHs is often complicated by the associated matrix. Organic and inorganic pollutants present in stainless steel dust particles have been investigated with the same laser microprobe mass spectrometer according to two original methodologies. These analytical methods do not require time-consuming pretreatment (extraction, solubilization) or preconcentration steps. More specifically, experiments are conducted with a Fourier transform ion cyclotron resonance mass spectrometer coupled to an ArF (193 nm) or a tripled frequency Nd-YAG (355 nm) laser. Experiments at 355 nm allow the nature of the most frequently occurring Cr(III)/Cr(VI) compounds in dust particles to be identified. Examination of PAHs at 193 nm is assisted by the formation of pi-complexes with 7,7',8,8'-tetracyanoquinodimethane to prevent their evaporation in the mass spectrometer during analysis and to ensure an increase in sensitivity.

Potential of laser mass spectrometry for the analysis of environmental dust particles—A review

“…LDI-MS or LA-MS is capable to provide qualitative information on the inorganic composition of particles through laser-generated cluster ions [100]. More specifically, methodologies have been developed to identify oxidation number of a given element [101]. Quantization of inorganic compounds is also complicate by the fact that a simple inorganic species as for example alkaline or alkaline earth chromates, leads to the formation of different cluster ions, whatever the used ion detection mode [200].…”

“…For each kind of particle constituent (inorganic, organic and also biological), laser parameters (energy and wavelength) can be adjusted to be as suited as possible for the efficient detection of all compounds of interest. As previously mentioned, the organic/inorganic composition of industrial dust particles has been determined with the same instrument by only varying the laser wavelength and energy [101,179]. Moreover, the detection of trace compounds (mineral or organic) may be easier accessible by off-line technique such as resonant (RIMS or REMPI) ionization.…”

“…More recently, the identification of the chromium chemical state in dust particles from different stainless steel factories has been achieved. Based on the proposed methodology in 2001 [98], semi-quantization for trivalent and hexavalent chromium compounds was achieved [101]. For the same particles, it was also possible with the same instrument to identify the pattern of polycyclic aromatic hydrocarbons (PAH) adsorbed at their surface by applying the methodology previously proposed by Carré et al [102].…”

“…For example, the analysis of organic and inorganic pollutants of the same industrial dust particles with the same FT-LMMS instrument was performed by using two specific optimized wavelengths: 193 nm for organics and 355 nm for inorganics [101]. In the last 10 years, LDI-MS was used for its ability to characterize the chemical composition of adsorbed species on combustion particles [104][105][106][107][108], diesel particles [102,109,110], dust particles [101], and particulate fraction of tobacco smokes [111]. Positive and negative detection modes appeared to be useful to analyze PAH and nitrated aromatic compounds [110], respectively with a good sensibility and selectivity.…”

Activation processes and polyethylene formation on a phillips model catalyst studied by laser ablation, laser desorption, and static secondary ion mass spectrometry

“…This behavior is associated with a modification of the cluster ion distribution, showing a dramatic decrease for the oxygenated species. As examples, see the modification in the relative intensity for SiO 2 [21], and applied in the investigation of pollutants in dust particles [30] is used. This methodology has been tested with various matrices and supports: note that this methodology is also applicable for powder [21].…”