Negative Ion Electrospray Ionization Mass Spectrum of Polyisobutenylsuccinic Anhydride:  Implications for Isobutylene Polymerization Mechanism

2002 ◽  
Vol 35 (7) ◽  
pp. 2494-2500 ◽  
Author(s):  
James J. Harrison ◽  
Cecilia M. Mijares ◽  
Michael T. Cheng ◽  
James Hudson
Keyword(s):  
Mass Spectrum ◽  
Electrospray Ionization ◽  
Negative Ion ◽  
Ionization Mass ◽  
Polymerization Mechanism ◽  
Ionization Mass Spectrum ◽  
Electrospray Ionization Mass Spectrum

scholarly journals Analysis of Flavonoids in Dalbergia odorifera by Ultra-Performance Liquid Chromatography with Tandem Mass Spectrometry

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 389 ◽  
Author(s):  
Xiangsheng Zhao ◽  
Shihui Zhang ◽  
Dan Liu ◽  
Meihua Yang ◽  
Jianhe Wei
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Electrospray Ionization ◽  
Negative Ion ◽  
Ionization Mass ◽  
Tandem Mass ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
Dalbergia Odorifera

Dalbergia odorifera, a traditional Chinese medicine, has been used to treat cardio- and cerebrovascular diseases in China for thousands of years. Flavonoids are major active compounds in D. odorifera. In this paper, a rapid and sensitive ultra-high performance liquid chromatography-triple quadrupole mass spectrometry method was developed and validated for simultaneous determination of 17 flavonoids in D. odorifera. Quantification was performed by multiple reaction monitoring using electrospray ionization in negative ion mode. Under the optimum conditions, calibration curves for the 17 analytes displayed good linearity (r2 > 0.9980). The intra- and inter-day precisions (relative standard deviations) were lower than 5.0%. The limit of quantitation ranged from 0.256 to 18.840 ng/mL. The mean recovery range at three spiked concentrations was 94.18–101.97%. The validated approach was successfully applied to 18 samples of D. odorifera. Large variation was observed for the contents of the 17 analytes. Sativanone and 3′-O-methylviolanone were the dominant compounds. The fragmentation behaviors of six flavonoids were investigated using UPLC with quadrupole time-of-flight tandem mass spectrometry. In negative ion electrospray ionization mass spectrometry, all the flavonoids yielded prominent [M − H]− ions. Fragments for losses of CH3, CO, and CO2 were observed in the mass spectra. Formononetin, liquiritigenin, isoliquiritigenin, sativanone, and alpinetin underwent retro-Diels–Alder fragmentations. The proposed method will be helpful for quality control of D. odorifera.

scholarly journals Analysis of Major Chemical Constituents in Luan-Pao-Prescription Using Liquid Chromatography Coupled with Electrospray Ionization Mass Spectrometry

2008 ◽  
Vol 3 (5) ◽  
pp. 1934578X0800300
Author(s):  
Jin-qiang Zhang ◽  
Min Yang ◽  
Bao-hong Jiang ◽  
Hui-lian Huang ◽  
Guang-tong Chen ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Electrospray Ionization ◽  
Chemical Constituents ◽  
Negative Ion ◽  
Female Sterility ◽  
Ionization Mass ◽  
Chinese Herbal ◽  
Major Chemical ◽  
First Time

Luan-Pao-Prescription is a famous Chinese herbal formula, which is commonly used for the treatment of female sterility in clinical practice in China. In the present paper, a reliable method based on liquid chromatography coupled with electrospray ionization tandem mass spectrometry in both positive and negative ion modes has been established for the analysis of major chemical constituents in Luan-Pao-Prescription. A total of 34 compounds were either identified or tentatively characterized. These compounds include flavonoids, anthraquinones, iridoids, xanthones and organic acids. Flavonoids were the major constituents of the formula. The results profiled the chemical composition of Luan-Pao-Prescription comprehensively for the first time.

Unexpected cytosine–AuCl4− interaction under electrospray ionization mass spectrometry conditions—Formation of cytosine–Au(I) complexes

2019 ◽  
Vol 26 (3) ◽  
pp. 225-229
Author(s):  
Magdalena Frańska ◽  
Emilia Konował
Keyword(s):  
Electrospray Ionization ◽  
Gas Phase ◽  
Mass Spectra ◽  
Mass Spectrometric ◽  
Negative Ion ◽  
Ionization Mass ◽  
Ionization Source ◽  
Full Scan ◽  
Negative Ion Mode ◽  
Product Ion Spectra

The interaction of cytosine with AuCl4−, under electrospray ionization mass spectrometric conditions, is discussed. On the basis of respective full scan mass spectra and product ion spectra, obtained in positive and negative ion mode, it has been deduced that cytosine is very prone to form Au(I)-containing complexes. The complexes may be formed in the gas phase by decomposition of Au(III)-containing complexes and also in the electrospray ionization source as a result of the occurrence of redox process. It has also been found that the interaction of cytosine with Au+ is stronger than that with Cu+ or Ag+, although taking into account the electrostatic attraction, it is not expected.

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