scholarly journals Evaluation of analytical methods to address Tungsten speciation

2013 ◽  
Vol 11 (3) ◽  
pp. 308-317 ◽  
Keyword(s):  
Mass Spectrometry ◽  
Raman Spectroscopy ◽  
Aqueous Solutions ◽  
Aging Time ◽  
Analytical Methods ◽  
Dominant Species ◽  
Narrow Range ◽  
Mass Analyzer ◽  
Ionization Mass ◽  
Desorption Ionization

Tungsten in solution may exist as a wide variety of species depending on concentration, pH, and aging time. Despite a substantial number of studies on this topic, the speciation of tungsten in aqueous solutions is still not completely understood. To address issues of fate, transport and potential bioavailability, it is necessary to be able to assess the speciation of tungsten in environmental systems. This study investigates the use of Laser Desorption/Ionization mass spectrometry combined with a Time-of-Flight mass analyzer (LDITOF) as well as Raman spectroscopy as potential techniques in speciation studies. Raman spectroscopy has been successful in identifying the dominant species under a narrow range of conditions. The ultimate goal is to extend the range of conditions and concentrations while also identifying subordinate species.

scholarly journals Diagnosis of Agglomeration and Crystallinity of Active Pharmaceutical Ingredients in Over the Counter Headache Medication by Electrospray Laser Desorption Ionization Mass Spectrometry Imaging

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 610
Author(s):  
Mariann Inga Van Meter ◽  
Salah M. Khan ◽  
Brynne V. Taulbee-Cotton ◽  
Nathan H. Dimmitt ◽  
Nathan D. Hubbard ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrometry Imaging ◽  
Laser Desorption ◽  
Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Active Pharmaceutical Ingredients ◽  
Laser Desorption Ionization ◽  
Over The Counter ◽  
Pharmaceutical Ingredients ◽  
Desorption Ionization

Agglomeration of active pharmaceutical ingredients (API) in tablets can lead to decreased bioavailability in some enabling formulations. In a previous study, we determined that crystalline APIs can be detected as agglomeration in tablets formulated with amorphous acetaminophen tablets. Multiple method advancements are presented to better resolve agglomeration caused by crystallinity in standard tablets. In this study, we also evaluate three “budget” over-the-counter headache medications (subsequently labeled as brands A, B, and C) for agglomeration of the three APIs in the formulation: Acetaminophen, aspirin, and caffeine. Electrospray laser desorption ionization mass spectrometry imaging (ELDI-MSI) was used to diagnose agglomeration in the tablets by creating molecular images and observing the spatial distributions of the APIs. Brand A had virtually no agglomeration or clustering of the active ingredients. Brand B had extensive clustering of aspirin and caffeine, but acetaminophen was observed in near equal abundance across the tablet. Brand C also had extensive clustering of aspirin and caffeine, and minor clustering of acetaminophen. These results show that agglomeration with active ingredients in over-the-counter tablets can be simultaneously detected using ELDI-MS imaging.

Analysis of microbial lipids deposited on Mars Global Simulant (MGS-1) by geomatrix-assisted laser desorption/ionization-mass spectrometry

2021 ◽  
pp. 1-7
Author(s):  
Alef dos Santos ◽  
Edson Rodrigues-Filho ◽  
Manoel Gustavo Petrucelli Homem
Keyword(s):  
Mass Spectrometry ◽  
Laser Desorption ◽  
Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Laser Desorption Ionization ◽  
Organic Substances ◽  
Microbial Lipids ◽  
Desorption Ionization ◽  
Martian Soil ◽  
Planetary Missions

Abstract Lipids are among the organic substances that can work as biosignatures, indicating life in an environment. We present an experimental investigation concerning analysis of lipids from a microbial source deposited on the Mars Global Simulant (MGS-1) regolith by geomatrix-assisted laser desorption/ionization-mass spectrometry (GALDI-MS). Our results indicate that lipids from intact microbial cells of a black yeast strain can be detected in these mimetic samples of Martian soil. These lipid molecules are predominantly associated with the occurrence of adducts in the GALDI-MS spectra. The results can be helpful in the planning of future planetary missions.

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