Enhanced Detection of Sialylated and Sulfated Glycans with Negative Ion Mode Nanoliquid Chromatography/Mass Spectrometry at High pH

2010 ◽  
Vol 82 (4) ◽  
pp. 1470-1477 ◽  
Author(s):  
Kristina A. Thomsson ◽  
Malin Bäckström ◽  
Jessica M. Holmén Larsson ◽  
Gunnar C. Hansson ◽  
Hasse Karlsson
Keyword(s):  
Mass Spectrometry ◽  
Negative Ion ◽  
High Ph ◽  
Chromatography Mass Spectrometry ◽  
Nanoliquid Chromatography ◽  
Negative Ion Mode

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>

Irace Level Detection of Chlorinated Paraffins in Biological and Environmental Samples, Using Gas Chromatography/Mass Spectrometry with Negative-Ion Chemical Ionization

1985 ◽  
Vol 68 (3) ◽  
pp. 427-430
Author(s):  
Peter P Schmid ◽  
Markus D Muller
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Environmental Samples ◽  
Chemical Ionization ◽  
Negative Ion ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Biological And Environmental Samples ◽  
Chlorinated Paraffins ◽  
Negative Ion Chemical Ionization

Abstract A method is described for detection of chlorinated paraffins (CPs) in biological and environmental samples. Sample preparation includes sulfuric acid treatment followed by adsorption chromatography on ilumina, which yields the CPs in one fraction that is almost free of interfering material. Using gas chromatography/mass spectrometry j with negative-ion chemical ionization, the limit of detection is 5 ng (corresponding to the lower ppb range). CP levels of 30 ppm, 200 ppb, ' and 5 ppb were found in sewage sludge, human fat, and sediment, respectively.

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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