scholarly journals Rapid discrimination between red and white ginseng based on unique mass-spectrometric features

2019 ◽  
Vol 164 ◽  
pp. 202-210 ◽  
Author(s):  
Qiang Zhao ◽  
Nan Zhao ◽  
Xueting Ye ◽  
Meixi He ◽  
Yiren Yang ◽  
...  
Keyword(s):  
Mass Spectrometric ◽  
White Ginseng ◽  
Rapid Discrimination ◽  
Unique Mass

scholarly journals Protein folding/refolding analysis by mass spectrometry. Scrambling of disulphide bridges in insulin

1990 ◽  
Vol 268 (3) ◽  
pp. 803-806 ◽  
Author(s):  
H R Morris ◽  
P Pucci ◽  
M Panico ◽  
G Marino
Keyword(s):  
Fast Atom Bombardment ◽  
Bovine Insulin ◽  
Mass Spectrometric ◽  
Spectrometric Analysis ◽  
Exact Nature ◽  
Disulphide Bridge ◽  
Protein Disulphide Isomerase ◽  
Disulphide Bonds ◽  
Definition Of ◽  
Unique Mass

In this paper we present a protocol that allows a dynamic analysis of disulphide-bridge formation, based on freezing the intermediates by acid/acetone precipitation, followed by digestion with pepsin and direct fast-atom-bombardment mass-spectrometric analysis. A rapid definition of the exact nature of disulphide bridges formed can be obtained via a definitive assignment of disulphide-linked peptides according to their unique mass values. With the use of an appropriate thiol concentration, scrambling of the native disulphide bonds in bovine insulin occurs, and the process is catalysed by protein disulphide-isomerase (EC 5.3.4.1). The disruption of native and the formation of new disulphide bonds can be monitored as described above, and interestingly B-chain dimers containing Cys-B7-Cys-B7 and Cys-B7-Cys-B19 bonds are detected.

scholarly journals Quantification of Lansoprazole in Oral Suspension by Ultra-High-Performance Liquid Chromatography Hybrid Ion-Trap Time-of-Flight Mass Spectrometry

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Stacy D. Brown ◽  
Justin D. Connor ◽  
Nicholas C. Smallwood ◽  
Ralph A. Lugo
Keyword(s):  
Liquid Chromatography ◽  
High Performance ◽  
Ion Trap ◽  
Time Of Flight ◽  
Ultra Performance Liquid Chromatography ◽  
Mass Spectrometric ◽  
Oral Suspension ◽  
Flight Mass Spectrometry ◽  
The Stability ◽  
Unique Mass

An LC-MS/MS method was developed and validated to be used as a stability indicating assay for the study of a 3 mg/mL lansoprazole oral suspension. The method utilizes a UPLC (ultra-performance liquid chromatography) column and unique mass spectrometric detection (ion-trap time-of-flight (IT-TOF)) to achieve a sensitive (LOD 2 ng/mL), accurate, and reproducible quantification of lansoprazole. This method reports an intraday and interday coefficient of variation of 2.98 ± 2.17% (n=5for each concentration for each day) and 3.07 ± 0.89% (n=20for each concentration), respectively. Calibration curves (5–25 μg/mL) were found to be linear with anR2value ranging from 0.9972 to 0.9991 on 4 different days. Accuracy of the assay, expressed as % error, ranged from 0.30 to 5.22%. This method is useful for monitoring the stability of lansoprazole in oral suspension.

A Questionnaire Survey on General Status and Opinions about Clinical Mass Spectrometric Analysis in Korea (2018)

2019 ◽  
Vol 9 (3) ◽  
pp. 161
Author(s):  
Sung-Eun Cho ◽  
Hyojin Chae ◽  
Hyung-Doo Park ◽  
Sail Chun ◽  
Yong-Wha Lee ◽  
...  
Keyword(s):  
Questionnaire Survey ◽  
Mass Spectrometric ◽  
Mass Spectrometric Analysis ◽  
Spectrometric Analysis ◽  
General Status

Mass Spectrometric Analysis of Porcine Rhodopsin¶

2002 ◽  
Vol 75 (3) ◽  
pp. 316 ◽  
Author(s):  
Zsolt Ablonczy ◽  
Patrice Goletz ◽  
Daniel R. Knapp ◽  
Rosalie K. Crouch
Keyword(s):  
Mass Spectrometric ◽  
Mass Spectrometric Analysis ◽  
Spectrometric Analysis

Tandem Mass Spectrometric Evaluation of Core Structures of Aromatic Compounds after Catalytic Deoxygenation

2017 ◽  
Author(s):  
Xueming Dong
Keyword(s):  
Aromatic Compounds ◽  
Supported Catalyst ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Aromatic Rings ◽  
Tandem Mass Spectrometric ◽  
Catalytic Deoxygenation ◽  
Oxygen Atoms

Catalytic deoxygenation of coal enhances the stability and combustion performance of coal-derived liquids. However, determination of the selectivity of removal of oxygen atoms incorporated in or residing outside of aromatic rings is challenging. This limits the ability to evaluate the success of catalytic deoxygenation processes. A mass spectrometric method, in-source collision-activated dissociation (ISCAD), combined with high resolution product ion detection, is demonstrated to allow the determination of whether the oxygen atoms in aromatic compounds reside outside of aromatic rings or are part of the aromatic system, because alkyl chains can be removed from aromatic cores via ISCAD. Application of this method for the analysis of a subbituminous coal treated using a supported catalyst revealed that the catalytic treatment reduced the number of oxygen-containing heteroaromatic rings but not the number of oxygen atoms residing outside the aromatic rings.<br>

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