Microprobe Speciation Analysis of Inorganic Solids by Fourier Transform Laser Mass Spectrometry

Abstract

Fourier transform (FT) laser microprobe mass spectrometry (LMMS) aims at the characterization of local constituents at the surface of solids. Signals from structural fragments specify the main building blocks of the analyte while adduct ions, consisting of one or two intact analyte molecules and a stable ion, allow specific identification of the molecule. A series of inorganic reference compounds including binary salts, oxides, and oxy salts was analyzed to assess the FT LMMS capabilities for the determination of the inorganic molecular composition. Compounds from different classes can be tentatively identified by deductive reasoning while those with the same elements in different stoichiometries require comparison with reference spectra.

Evidence for biological activity in mineralization of secondary sulphate deposits in a basaltic environment: implications for the search for life in the Martian subsurface

“…Such distinction between an inorganic and organic ion based on the peak's mass defect is easily achieved when the ion has a mass-to-charge (m/z) ratio less than 400, because inorganic ions tend to have mass defects that are near to or would round up to next nominal integer mass, whereas bio/organic compounds tend to have mass defects that would round down to next integer mass. 5) shows several high mass peaks, most of which are easily identified as inorganic based on their mass defects (values were generally >0.5 u), their occurrence in the inorganic standard spectra and inorganic peaks (such as m/z 165 and 181) that have been previously reported in Na 2 SO 4 spectra (Poels et al 1998;Van Vaeck et al 1998;Ignatova et al 2003;Richardson et al 2009). organic ions accumulate enough hydrogen atoms causing the mass defect to appear to indicate inorganic elements as the m/z value approaches the next integer).…”

“…To assist in identification of any associated bio/organic peaks in the mass spectra from the COM secondary deposits, the spectra were compared with a suite of FTICR-MS standard spectra of inorganic thenardite, Na-carbonate (trona, natron), and physical combinations between these Na-sulphate and Na-carbonate minerals (Richardson et al 2008(Richardson et al , 2009(Richardson et al , 2012. The inorganic peaks observed in the spectrum have been reported in previous studies of Na-sulphate spectra (Poels et al 1998;Van Vaeck et al 1998;Richardson et al 2008Richardson et al , 2012. the non-integer value after the decimal point) suggestive of inorganic constituents.…”

Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA‐ICPMS)

“…On the basis of this emission, elements present in the vaporized material can be identified and quantified using a calibration curve. A second -less common -application is laser ablation mass spectrometry (LAMS) [27,28], where the ions formed during the ablation process are directly transferred into a mass spectrometer for analysis. Both former approaches are somewhat limited for quantitative analysis of samples, where matrix-matched calibration standards are not readily available [29][30][31].…”

Electrospray Ionization Based Methods for the Generation of Polynuclear Oxo- and Hydroxo Group 6 Anions in the Gas-Phase

“…[14] In the last decade, the use of laser evaporation techniques has been dominant for the gas-phase production of group 6 oxide clusters. [13,[15][16][17] As illustrated in the gas-phase generation of [18,19] laser evaporation techniques typically generate an assortment of oxo-clusters with different stoichiometries and nuclearities.…”