Identification of flavonoids in Dendrobium huoshanense and comparison with those in allied species of Dendrobium by TLC, HPLC and HPLC coupled with electrospray ionization multi‐stage tandem MS analyses

2019 ◽  
Author(s):  
Zhi‐Yun Liang ◽  
Jun‐Yi Zhang ◽  
Yue‐Chun Huang ◽  
Chu‐Juan Zhou ◽  
Ya‐Wen Wang ◽  
...  
Keyword(s):  
Electrospray Ionization ◽  
Tandem Ms ◽  
Multi Stage ◽  
Dendrobium Huoshanense

UHPLC/ESI-MS/MS Determination of 187 Pesticides in Wine

2016 ◽  
Vol 99 (2) ◽  
pp. 539-557 ◽  
Author(s):  
Jian Wang ◽  
Wendy Cheung
Keyword(s):  
Measurement Uncertainty ◽  
Electrospray Ionization ◽  
Pesticide Residues ◽  
Red Wine ◽  
White Wine ◽  
Tandem Ms ◽  
Fast Method ◽  
Intermediate Precision ◽  
Method Performance ◽  
Standard Calibration

Abstract This paper presents an ultra HPLC/electrospray ionization-tandem MS method to determine pesticides in wine. We adopted the quick, easy, cheap, effective, rugged, and safe (QuEChERs) method for extraction and used core-shell column to achieve ultra-HPLC to develop and validate a simple and fast method to analyze 187 pesticide residues in red and white wine samples. Pesticide residues were extracted from wine samples using QuEChERS. Ultra HPLC/electrospray ionization-tandem MS quantification was achieved using matrix-matched standard calibration curves with isotopically labeled standards or a chemical analogue as internal standards with an analytical range from 5.0 to 500.0 μg/L. The method performance characteristics that included overall recovery, intermediate precision, and measurement uncertainty were evaluated according to a nested experimental design. Generally, 98.4% (in red wine) and 96.8% (in white wine) of the pesticides had recoveries between 71 and 120%; 98.9% (in red wine) and 99.5% (in white wine) of the pesticides had the intermediate precision ≤20%; and 99.5% (in red wine) and 98.4% (in white wine) of the pesticides had measurement uncertainty ≤50%.

Electrospray Ionization Tandem Mass Spectrometry Investigation of the Polymerization of Tetrahydrofuran Initiated by Phosphorus Oxychloride

2005 ◽  
Vol 11 (3) ◽  
pp. 319-324 ◽  
Author(s):  
Gui-Ji Zhou ◽  
Peng-Xiang Xu ◽  
Yong Yeb ◽  
Yu-Fen Zhao
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Electrospray Ionization ◽  
Ring Opening ◽  
Phosphorus Oxychloride ◽  
Tandem Mass ◽  
Multi Stage ◽  
Ionization Tandem Mass Spectrometry

Phosphorus oxychloride was found to induce ring opening of tetrahydrofuran (THF) to synthesize THF oligomer incorporated phosphate. Electrospray ionization multi-stage tandem mass spectrometry was used to study the products and confirm the structures.

Determination of Sterigmatocystin in Infant Cereals from Hangzhou, China

2016 ◽  
Vol 99 (5) ◽  
pp. 1273-1278 ◽  
Author(s):  
Shaoying Liu ◽  
Jicai Fan ◽  
Xihui Huang ◽  
Quan Jin ◽  
Guonian Zhu
Keyword(s):  
Electrospray Ionization ◽  
Analytical Method ◽  
Diode Array ◽  
Tandem Ms ◽  
Diode Array Detection ◽  
Simple Method ◽  
Esi Ms ◽  
Array Detection ◽  
Ionization Mode

Abstract A simple method was developed for the determination of sterigmatocystin in infant cereals. The method consists of a quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction approach and cleanup with an SPE HLB cartridge. After purification for separation and quantification of sterigmatocystin, HPLC with UV detection and diode-array detection (DAD) was used at sterigmatocystin levels >10 μg/kg, whereas ultra-performance LC with electrospray ionization (ESI) and tandem MS (MS/MS) was used at levels <10 μg/kg. The compound was determined by UV-DAD at 325 nm and by ESI-MS/MS in the positive ionization mode. Good r2 values (≥0.99) were found with both UV-DAD and ESI-MS/MS, and satisfactory recoveries (84.8–96.2%) of sterigmatocystin in infant cereals were demonstrated, with RSD values ≤11.43%. The developed analytical method was used for the determination of sterigmatocystin in infant cereals from Hangzhou, China.

scholarly journals Isolation and characterization of protoporphyrin glycoconjugates from rat Harderian gland by HPLC, capillary electrophoresis and HPLC/electrospray ionization MS

2000 ◽  
Vol 347 (3) ◽  
pp. 757-761 ◽  
Author(s):  
Chang Kee LIM ◽  
M. Aaqib RAZZAQUE ◽  
Jinli LUO ◽  
Peter B. FARMER
Keyword(s):  
Capillary Electrophoresis ◽  
Electrospray Ionization ◽  
Harderian Gland ◽  
Tandem Ms ◽  
Isolation And Characterization ◽  
Harderian Glands ◽  
On Line ◽  
Identification And Characterization

It has been widely reported that the Harderian gland, present in most vertebrates, accumulates high levels of porphyrins, particularly protoporphyrin. The present study describes the extraction, identification and characterization of a group of hitherto unreported protoporphyrin glycoconjugates in the rat Harderian gland using HPLC, capillary electrophoresis, on-line HPLC/electrospray ionization MS and tandem MS. The major glycoconjugate was identified as protoporphyrin-1-O-acyl β-xyloside with a smaller amount of protoporphyrin-1-O-acyl β-glucoside also detected. In the Harderian glands studied, 50-70% of the porphyrins present were in the form of protoporphyrin glycoconjugates. This is the first reported occurrence of glycoconjugates of porphyrins in Nature and suggests that previous studies have wrongly identified the major porphyrin in the Harderian gland as the unconjugated protoporphyrin.

Sign in / Sign up

Export Citation Format

Share Document