Papers by Keyword: HPLC-MS

Abstract: In this paper, HPLC-ESI-MS technique was used to analyze the methanol extract of the seed of Vaccaria segetalis (Necr.) Gracke, known as Wang-Bu-Liu-Xing in traditional Chinese medicine. By the studies of MS and MS/MS spectra and the comparison with reference compounds, five main constituents were identified, including hypaphorine, vaccarin, isosaporarin, isovitexin 2''-O-arabinoside and vaccarin H.

Abstract: QuEChERS is an acetonitrile partitioning and dispersive solid-phase extraction (D-SPE) method that widely used in the analysis of multiple classes of pesticide residues in vegetable and fruit. In this paper, we modified it to fulfill analysis on much more complex matrix-Chinese herbal medicine, and High Performance Liquid Chromatography-Mass Spectrometry (HPLC-MS) was chosen for analysis. This method could be applied to quantitative and qualitative analysis of a wide range of pesticides in Chinese herbal medicine (Fructus Aurantii Immaturus as sample).

Abstract: It is well known that microcystins (MCs) are the most abundant toxins produced by cyanobacteria in freshwater. The separation and characterization of MCs isomers are very important to the research of algal pollution in freshwater. In this paper MCs isomers were extracted by using methanol water solution and separated by reverse phase high performance liquid chromatography (HPLC). The different isomers were characterized by using HPLC-MS method. Different ratio of extract solvent and chromatographic conditions were discussed. Five MCs isomers were successfully extracted from cyanobacteria of Dianchi Lake. Three of which were characterized to be MC-RR, MC-YR and MC-LR, 1.5mg (92.3 purity) of MC-LR was prepared by using a semi-preparation HPLC system.

Abstract: The suitability of high performance liquid chromatography (HPLC) for the direct determination of the concentration of complexing agents for single chemistry cleaning is demonstrated. HPLC, coupled to a mass spectrometric detector (HPLC-MS) and two-dimensional mass spectrometry (MS/MS) have been applied for the investigation of the reactions involved in the decomposition of the complexing agents. The techniques described are useful for determining the stability of organic additives in wet chemical cleaning baths.