Confounding contaminants in mass spectrometric reaction monitoring

2018 ◽  
Author(s):  
Gilian T. Thomas ◽  
Landon MacGillivray ◽  
Natalie L. Dean ◽  
Rhonda L. Stoddard ◽  
Lars Yunker ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrometric ◽  
Negative Ion ◽  
Reaction Monitoring ◽  
Schlenk Flask ◽  
Dynamic Analyses ◽  
Rubber Septa ◽  
Negative Ion Mode ◽  
Mode A

<p>Reactions carried out in the presence of rubber septa run the risk of additives being leached out by the solvent. Normally, such species are present at low enough levels that they do not interfere with the reaction significantly. However, when studying reactions using sensitive methods such as mass spectrometry, the appearance of even trace amounts of material can confuse dynamic analyses of reactions. A wide variety of additives are present in rubber along with the polymer: antioxidants, dyes, detergent, and vulcanization agents, and these are all especially problematic in negative ion mode. A redesigned Schlenk flask for pressurized sample infusion (PSI) is presented as a means of practically eliminating the presence of contaminants during reaction analyses.</p>

Confounding contaminants in mass spectrometric reaction monitoring

2019 ◽  
Author(s):  
Gilian T. Thomas ◽  
Landon MacGillivray ◽  
Natalie L. Dean ◽  
Rhonda L. Stoddard ◽  
Lars Yunker ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrometric ◽  
Negative Ion ◽  
Reaction Monitoring ◽  
Schlenk Flask ◽  
Dynamic Analyses ◽  
Rubber Septa ◽  
Negative Ion Mode ◽  
Mode A

<p>Reactions carried out in the presence of rubber septa run the risk of additives being leached out by the solvent. Normally, such species are present at low enough levels that they do not interfere with the reaction significantly. However, when studying reactions using sensitive methods such as mass spectrometry, the appearance of even trace amounts of material can confuse dynamic analyses of reactions. A wide variety of additives are present in rubber along with the polymer: antioxidants, dyes, detergent, and vulcanization agents, and these are all especially problematic in negative ion mode. A redesigned Schlenk flask for pressurized sample infusion (PSI) is presented as a means of practically eliminating the presence of contaminants during reaction analyses.</p>

Confounding contaminants in mass spectrometric reaction monitoring

2019 ◽  
Author(s):  
Gilian T. Thomas ◽  
Landon MacGillivray ◽  
Natalie L. Dean ◽  
Rhonda L. Stoddard ◽  
Lars Yunker ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrometric ◽  
Negative Ion ◽  
Reaction Monitoring ◽  
Schlenk Flask ◽  
Dynamic Analyses ◽  
Rubber Septa ◽  
Negative Ion Mode ◽  
Mode A

<p>Reactions carried out in the presence of rubber septa run the risk of additives being leached out by the solvent. Normally, such species are present at low enough levels that they do not interfere with the reaction significantly. However, when studying reactions using sensitive methods such as mass spectrometry, the appearance of even trace amounts of material can confuse dynamic analyses of reactions. A wide variety of additives are present in rubber along with the polymer: antioxidants, dyes, detergent, and vulcanization agents, and these are all especially problematic in negative ion mode. A redesigned Schlenk flask for pressurized sample infusion (PSI) is presented as a means of practically eliminating the presence of contaminants during reaction analyses.</p>

Determination of Tobacco Specific Hemoglobin Adducts in Smoking Mothers and New Born Babies by Mass Spectrometry

2007 ◽  
Vol 2 ◽  
pp. 117727190700200 ◽  
Author(s):  
Steven R. Myers ◽  
Yeakub Ali
Keyword(s):  
Mass Spectrometry ◽  
Biological Markers ◽  
Chemical Ionization ◽  
Mass Spectrometric ◽  
Negative Ion ◽  
Gas Chromatography Mass Spectrometry ◽  
Spectrometric Analysis ◽  
Hemoglobin Adducts ◽  
Environmental Carcinogens ◽  
Negative Ion Mode

Biological markers for assessment of exposure to a variety of environmental carcinogens has been widely applied in both basic as well as clinical research. Exposure to tobacco smoke presents an ideal environment with which to develop, characterize, and refine biological markers, especially of those carcinogens found in tobacco. In the present study, a sensitive gas chromatography/mass spectrometry (GC/MS) method was developed to measure nitrosamine- hemoglobin adducts (HPB-Hb (4-Hydroxy-3-pyridinyl-1-butanone) at trace levels in red blood cells of both African-American and Caucasian smoking and nonsmoking mothers and their infants. Gas chromatographic and mass spectrometric methods with chemical ionization (CI) of methane reagent gas in both positive and negative ion mode as well as electron ionization (EI) were studied to determine differences in sensitivity of detection among the various ionization methods. Detection limits using both positive and negative chemical ionization modes were found to be 30 femtomoles of HPB, whereas detection using electron impact modes yielded a detection limit of 80 femtomoles of HBP. Comparative derivatization of HPB was performed using O-bis(Trimethylsilyl)-trifluoroacetamide (BSTFA) and 2, 3, 4, 5, 6-Pentafluorobenzoylchloride (PFBC). Both Negative CI and Positive CI modes of analysis were compared to the more widely accepted EI modes of mass spectrometric analysis.

Pregnanediol-3 alpha-glucuronide measured in diluted urine by mass spectrometry with fast atom bombardment/negative-ion ionization.

1985 ◽  
Vol 31 (1) ◽  
pp. 46-49 ◽  
Author(s):  
G Moneti ◽  
G Agati ◽  
M G Giovannini ◽  
M Pazzagli ◽  
R Salerno ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Fast Atom Bombardment ◽  
Internal Standard ◽  
Mass Spectrometric ◽  
Negative Ion ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Ionization Technique ◽  
Fast Atom Bombardment Ionization ◽  
Negative Ion Mode

Abstract We describe a mass-spectrometric method based on the fast atom bombardment ionization technique in the negative-ion mode for measuring pregnanediol-3 alpha-glucuronide in diluted urine from women. The procedure requires addition of testosterone-17 beta-D-glucuronide (2.5 micrograms/25 microL) to the urine sample as internal standard, and the sample is added directly to the fast atom bombardment target with no further manipulation. We have assessed and evaluated the method by the traditional criteria of reliability.

Optimization of parameters affecting signal intensity in an LTQ-orbitrap in negative ion mode: A design of experiments approach

Talanta ◽  
2016 ◽  
Vol 147 ◽  
pp. 402-409 ◽  
Author(s):  
Nikolaos Lemonakis ◽  
Alexios-Leandros Skaltsounis ◽  
Anthony Tsarbopoulos ◽  
Evagelos Gikas
Keyword(s):  
Design Of Experiments ◽  
Signal Intensity ◽  
Negative Ion ◽  
Optimization Of Parameters ◽  
Negative Ion Mode ◽  
Mode A

scholarly journals Investigation of electrospray for a capillary electrophoresis–mass spectrometry interface in reverse polarity and negative ion mode

2019 ◽  
Vol 25 (1) ◽  
pp. 157-163 ◽  
Author(s):  
Morgan Stickney ◽  
Qiangwei Xia ◽  
I Jonathan Amster
Keyword(s):  
Mass Spectrometry ◽  
Electroosmotic Flow ◽  
Negative Ion ◽  
Reverse Polarity ◽  
Sheath Flow ◽  
Analytical Technique ◽  
Sheath Liquid ◽  
Electrospray Process ◽  
Negative Ionization ◽  
Negative Ion Mode

Capillary zone electrophoresis (CZE) paired with mass spectrometry (MS) is a powerful analytical technique for examining mixtures of ionic analytes such as glycosaminoglycans. This study examines the mechanics of the electrospray process for a sheath flow CZE-MS interface under reverse polarity negative ionization conditions. Liquid flow in a sheath flow nano-electrospray CZE-MS interface is driven by two mechanisms, electroosmotic flow and electrospray nebulization. The contribution of these two processes to the overall flow of solution to the electrospray tip is influenced by the surface coatings of the sheath flow emitter tip and by the solvent composition. We have investigated the application of this interface to the reverse polarity separation of glycosaminoglycans and find that the role of electroosmotic flow is far less than has been reported previously, and the electrospray process itself is the largest contributor to the flow of the sheath liquid.

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