The ion-molecule reactions of disubstituted benzenes with the ion system of acetyl chloride under the chemical ionization condition were examined and the fragmentation reactions of the adduct ions formed by the ion-mo...The ion-molecule reactions of disubstituted benzenes with the ion system of acetyl chloride under the chemical ionization condition were examined and the fragmentation reactions of the adduct ions formed by the ion-molecule reactions were studied by using collision-induced dissociation technique. It was found that the electron-releasing groups favored the adduct reactions and the electron-withdrawing groups did not. The position and properties of substituting groups had an effect on the relative abundance of the adduct ions. The fragmentation reaction of the adduct ions formed by ortho-benzene diamine with the acetyl ion was similar to the reductive alkylation reaction of amine in condensed phase.展开更多
Ginsenoside compound K(GCK), the main metabolite of protopanaxadiol constituents of Panax ginseng, easily produces alkali metal adduct ions during mass spectrometry particularly with lithium. Accordingly, we have deve...Ginsenoside compound K(GCK), the main metabolite of protopanaxadiol constituents of Panax ginseng, easily produces alkali metal adduct ions during mass spectrometry particularly with lithium. Accordingly, we have developed a rapid and sensitive liquid chromatography–tandem mass spectrometric method for analysis of GCK in human plasma based on formation of a lithium adduct. The analyte and paclitaxel(internal standard) were extracted from 50 m L human plasma using methyl tertbutyl ether. Chromatographic separation was performed on a Phenomenex Gemini C18 column(50 mm 2.0 mm; 5 μm) using stepwise gradient elution with acetonitrile–water and 0.2 mmol/L lithium carbonate at a flow rate of 0.5 m L/min. Detection was performed in the positive ion mode using multiple reaction monitoring of the transitions at m/z 629-449 for the GCK-lithium adduct and m/z 860-292 for the adduct of paclitaxel. The assay was linear in the concentration range 1.00–1000 ng/m L(r^2>40.9988)with intra- and inter-day precision of ±8.4% and accuracy in the range of 4.8% to 6.5%. Recovery,stability and matrix effects were all satisfactory. The method was successfully applied to a pharmacokinetic study involving administration of a single GCK 50 mg tablet to healthy Chinese volunteers.展开更多
文摘The ion-molecule reactions of disubstituted benzenes with the ion system of acetyl chloride under the chemical ionization condition were examined and the fragmentation reactions of the adduct ions formed by the ion-molecule reactions were studied by using collision-induced dissociation technique. It was found that the electron-releasing groups favored the adduct reactions and the electron-withdrawing groups did not. The position and properties of substituting groups had an effect on the relative abundance of the adduct ions. The fragmentation reaction of the adduct ions formed by ortho-benzene diamine with the acetyl ion was similar to the reductive alkylation reaction of amine in condensed phase.
文摘Ginsenoside compound K(GCK), the main metabolite of protopanaxadiol constituents of Panax ginseng, easily produces alkali metal adduct ions during mass spectrometry particularly with lithium. Accordingly, we have developed a rapid and sensitive liquid chromatography–tandem mass spectrometric method for analysis of GCK in human plasma based on formation of a lithium adduct. The analyte and paclitaxel(internal standard) were extracted from 50 m L human plasma using methyl tertbutyl ether. Chromatographic separation was performed on a Phenomenex Gemini C18 column(50 mm 2.0 mm; 5 μm) using stepwise gradient elution with acetonitrile–water and 0.2 mmol/L lithium carbonate at a flow rate of 0.5 m L/min. Detection was performed in the positive ion mode using multiple reaction monitoring of the transitions at m/z 629-449 for the GCK-lithium adduct and m/z 860-292 for the adduct of paclitaxel. The assay was linear in the concentration range 1.00–1000 ng/m L(r^2>40.9988)with intra- and inter-day precision of ±8.4% and accuracy in the range of 4.8% to 6.5%. Recovery,stability and matrix effects were all satisfactory. The method was successfully applied to a pharmacokinetic study involving administration of a single GCK 50 mg tablet to healthy Chinese volunteers.
基金ACKNOWLEDGMENTS This work was supported by the Innovation Foundation of Graduate Students in University of Science and Technology of China （No.KD2008020）, and the Natural Science Foundation of Anhui Province （No.090416228）.
