scholarly journals On Topological Analysis of fs-LIMS Data. Implications for in Situ Planetary Mass Spectrometry

2021 ◽  
Vol 4 ◽  
Author(s):  
Rustam A. Lukmanov ◽  
Andreas Riedo ◽  
David Wacey ◽  
Niels F. W. Ligterink ◽  
Valentine Grimaudo ◽  
...  

In this contribution, we present results of non-linear dimensionality reduction and classification of the fs laser ablation ionization mass spectrometry (LIMS) imaging dataset acquired from the Precambrian Gunflint chert (1.88 Ga) using a miniature time-of-flight mass spectrometer developed for in situ space applications. We discuss the data generation, processing, and analysis pipeline for the classification of the recorded fs-LIMS mass spectra. Further, we define topological biosignatures identified for Precambrian Gunflint microfossils by projecting the recorded fs-LIMS intensity space into low dimensions. Two distinct subtypes of microfossil-related spectra, a layer of organic contamination and inorganic quartz matrix were identified using the fs-LIMS data. The topological analysis applied to the fs-LIMS data allows to gain additional knowledge from large datasets, formulate hypotheses and quickly generate insights from spectral data. Our contribution illustrates the utility of applying spatially resolved mass spectrometry in combination with topology-based analytics in detecting signatures of early (primitive) life. Our results indicate that fs-LIMS, in combination with topological methods, provides a powerful analytical framework and could be applied to the study of other complex mineralogical samples.

2009 ◽  
Vol 2 (1) ◽  
pp. 119-151 ◽  
Author(s):  
J. P. Kercher ◽  
T. P. Riedel ◽  
J. A. Thornton

Abstract. We report a new method for the simultaneous in situ detection of nitryl chloride (ClNO2) and dinitrogen pentoxide (N2O5) using chemical ionization mass spectrometry (CIMS). The technique relies on the formation and detection of iodide ion-molecule clusters, I(ClNO2)− and I(N2O5)−. The novel N2O5 detection scheme is direct. It does not suffer from high and variable chemical interferences, which are associated with the typical method of nitrate anion detection. We address the role of water vapor, electric field strength, and instrument zero determinations, which influence the overall sensitivity and detection limit of this method. For both species, the method demonstrates high sensitivity (>1 Hz/pptv), precision (~10% for 100 pptv in 1 s), and accuracy (~20%), the latter ultimately determined by the nitrogen dioxide (NO2) cylinder calibration standard and characterization of inlet effects. For the typically low background signals (<10 Hz) and high selectivity, we estimate signal-to-noise (S/N) ratios of 2 for 1 pptv in 60 s averages, but uncertainty associated with the instrumental zero currently leads to an ultimate detection limit of ~5 pptv for both species. We validate our approach for the simultaneous in situ measurement of ClNO2 and N2O5 while on board the Research Vessel (RV) Knorr as part of the ICEALOT 2008 Field Campaign.


Minerals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 91 ◽  
Author(s):  
Kandy Wang ◽  
Ian Graham ◽  
Laure Martin ◽  
Panagiotis Voudouris ◽  
Gaston Giuliani ◽  
...  

In this study, the oxygen isotope (δ18O) composition of pink to red gem-quality rubies from Paranesti, Greece was investigated using in-situ secondary ionization mass spectrometry (SIMS) and laser-fluorination techniques. Paranesti rubies have a narrow range of δ18O values between ~0 and +1‰ and represent one of only a few cases worldwide where δ18O signatures can be used to distinguish them from other localities. SIMS analyses from this study and previous work by the authors suggests that the rubies formed under metamorphic/metasomatic conditions involving deeply penetrating meteoric waters along major crustal structures associated with the Nestos Shear Zone. SIMS analyses also revealed slight variations in δ18O composition for two outcrops located just ~500 m apart: PAR-1 with a mean value of 1.0‰ ± 0.42‰ and PAR-5 with a mean value of 0.14‰ ± 0.24‰. This work adds to the growing use of in-situ methods to determine the origin of gem-quality corundum and re-confirms its usefulness in geographic “fingerprinting”.


The Analyst ◽  
2020 ◽  
Vol 145 (9) ◽  
pp. 3313-3319
Author(s):  
Zhongbao Han ◽  
Xiaoyu Gu ◽  
Shirong Wang ◽  
Liyan Liu ◽  
Ying Wang ◽  
...  

We report the application of PESI-MS to in situ monitoring of photocatalytic reactions of cationic dyes in suspensions in real-time.


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