scholarly journals Negative ion mode evolution of potential buildup and mapping of potential gradients within the electrospray emitter

2004 ◽  
Vol 15 (12) ◽  
pp. 1737-1747 ◽  
Author(s):  
Boguslaw P. Pozniak ◽  
Richard B. Cole
Keyword(s):  
Negative Ion ◽  
Potential Gradients ◽  
Negative Ion Mode ◽  
Electrospray Emitter

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>

scholarly journals Dopant-Enriched Nitrogen Gas for Enhanced Electrospray Ionization of Released Glycans in Negative Ion Mode

2021 ◽  
Author(s):  
Katarina Madunić ◽  
Sander Wagt ◽  
Tao Zhang ◽  
Manfred Wuhrer ◽  
Guinevere S.M. Lageveen-Kammeijer
Keyword(s):  
Electrospray Ionization ◽  
Negative Ion ◽  
Nitrogen Gas ◽  
Negative Ion Mode

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 Fast Sensing of Hydrogen Cyanide (HCN) Vapors Using a Hand-Held Ion Mobility Spectrometer with Nonradioactive Ionization Source

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5045
Author(s):  
Victor Bocos-Bintintan ◽  
Ileana Andreea Ratiu
Keyword(s):  
Ion Mobility ◽  
Hydrogen Cyanide ◽  
Limit Of Detection ◽  
Chemical Warfare Agent ◽  
Source Model ◽  
Negative Ion ◽  
Industrial Chemicals ◽  
Ionization Source ◽  
Toxic Industrial Chemicals ◽  
Negative Ion Mode

Sensitive real-time detection of vapors produced by toxic industrial chemicals (TICs) always represents a stringent priority. Hydrogen cyanide (HCN) is definitely a TIC, being widely used in various industries and as an insecticide; it is a reactive, very flammable, and highly toxic compound that affects the central nervous system, cardiovascular system, eyes, nose, throat, and also has systemic effects. Moreover, HCN is considered a blood chemical warfare agent. This study was focused toward quick detection and quantification of HCN in air using time-of-flight ion mobility spectrometry (ToF IMS). Results obtained clearly indicate that IMS can rapidly detect HCN at sub-ppmv levels in air. Ion mobility spectrometric response was obtained in the negative ion mode and presented one single distinct product ion, at reduced ion mobility K0 of 2.38 cm2 V−1 s−1. Our study demonstrated that by using a miniaturized commercial IMS system with nonradioactive ionization source model LCD-3.2E (Smiths Detection Ltd., London, UK), one can easily measure HCN at concentrations of 0.1 ppmv (0.11 mg m−3) in negative ion mode, which is far below the OSHA PEL-TWA value of 10 ppmv. Measurement range was from 0.1 to 10 ppmv and the estimated limit of detection LoD was ca. 20 ppbv (0.02 mg m−3).

Comprehensive and Rapid Identification of Astilbin Metabolites in Rats Based on Multiple Metabolite Templates Combined with UHPLC-Q-ExactiveMass Spectrometry

2021 ◽  
Vol 22 ◽  
Author(s):  
Shan Jiang ◽  
Haoran Li ◽  
Ailin Yang ◽  
Hongbing Zhang ◽  
Pingping Dong ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Biological Effects ◽  
Rat Plasma ◽  
Rapid Identification ◽  
Negative Ion ◽  
Ring Cleavage ◽  
Rat Urine ◽  
Q Exactive ◽  
Negative Ion Mode

Background : Astilbin, a dihydroflavonoid compound widely found in plants, exhibits a variety of pharmacological activities and biological effects. However, little is known about the metabolism of this active compound in vivo, which is very helpful for elucidating the pharmacodynamic material basis and application of astilbin. Objective: To establish a rapid profiling and identification method for metabolites in rat urine, faeces and plasma using a UHPLC-Q-Exactive mass spectrometer in negative ion mode. Methods: In this study, a simple and rapid systematic strategy and 7 metabolite templates, which were established based on previous reports, were utilized to screen and identify astilbin metabolites. Results: As a result, a total of 72 metabolites were detected and characterized, among which 33 metabolites were found in rat urine, while 28 and 38 metabolites were characterized from rat plasma and faeces, respectively. These metabolites were presumed to be generated through ring cleavage, sulfation, dehydrogenation, methylation, hydroxylation, glucuronidation, dehydroxylation and their composite reactions. Conclusion: This study illustrated the capacity of the sensitive UHPLC-Q-Exactive mass spectrometer analytical system combined with the data-mining methods to rapidly elucidate the unknown metabolism. Moreover, the comprehensive metabolism study of astilbin provided an overall metabolic profile, which will be of great help in predicting the in vivo pharmacokinetic profiles and understanding the action mechanism of this active ingredient.

scholarly journals DESI Spray Stability in the Negative Ion Mode Is Dependent on Relative Humidity

2018 ◽  
Vol 30 (2) ◽  
pp. 376-380 ◽  
Author(s):  
Clara L. Feider ◽  
Rachel J. DeHoog ◽  
Marta Sans ◽  
Jialing Zhang ◽  
Anna Krieger ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Negative Ion ◽  
Negative Ion Mode

scholarly journals Relative quantitative analysis of human plasma O‑sulfotyrosine using HPLC‑MS/MS in linear negative ion mode

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Daopeng Dai ◽  
Zhanwei Ruan ◽  
Hui Han ◽  
Jinzhou Zhu ◽  
Ruiyan Zhang
Keyword(s):  
Quantitative Analysis ◽  
Human Plasma ◽  
Negative Ion ◽  
Negative Ion Mode

Serum Lipids Profiling Perturbances in Patients with Ischemic Heart Disease and Ischemic Cardiomyopathy

2020 ◽  
Author(s):  
Lin Yang ◽  
Liang Wang ◽  
Yangyang Deng ◽  
Lizhe Sun ◽  
Bowen Low ◽  
...  
Keyword(s):  
Heart Disease ◽  
Ischemic Heart Disease ◽  
Ischemic Cardiomyopathy ◽  
Serum Lipids ◽  
Ischemic Heart ◽  
Negative Ion ◽  
Serum Samples ◽  
Cross Sectional ◽  
Negative Ion Mode ◽  
Positive Ion

Abstract Background: Ischemic heart disease (IHD) is a common cardiovascular disorder associated with inadequate blood supply to the myocardium. Chronic coronary ischemia leads to ischemic cardiomyopathy (ICM). Despite their rising prevalence and morbidity, few studies have discussed the lipids alterations in these patients. Methods: In this cross-sectional study, we analyzed serum lipids profile in IHD and ICM patients using a lipidomics approach. Consecutive consenting patients admitted to the hospital for IHD and ICM were enrolled. Serum samples were obtained after overnight fasting. Non-targeted metabolomics was applied to demonstrate lipids metabolic profile in control, IHD and ICM patients. Results: A total of 63 and 62 lipids were detected in negative and positive ion mode respectively. Among them, 16:0 Lyso PI, 18:1 Lyso PI in negative ion mode, and 19:0 Lyso PC, 12:0 SM d18:1/12:0, 15:0 Lyso PC, 17:0 PC, 18:1-18:0 PC in positive ion mode were significantly altered both in IHD and ICM as compared to control. 13:0 Lyso PI, 18:0 Lyso PI, 16:0 PE, 14:0 PC DMPC, 16:0 ceramide, 18:0 ceramide in negative ion mode, and 17:0 PE, 19:0 PC, 14:0 Lyso PC, 20:0 Lyso PC, 18:0 PC DSPC, 18:0-22:6 PC in positive ion mode were significantly altered only in ICM as compared to IHD and control. Conclusion: Using non-targeted lipidomics profiling, we have successfully identified a group of circulating lipids that were significantly altered in IHD and ICM. The lipids metabolic signatures shed light on potential new biomarkers and therapeutics for preventing and treating ICM.

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