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Wang X.,Catholic University of Leuven | Dou Z.,Tianjin University of Traditional Chinese Medicine | Yuan Y.,Jiangsu Provincial Institute for Food and Drug Control | Man S.,Tianjin University of Science and Technology | And 3 more authors.
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2013

Capillary electrophoresis (CE) with the use of mass spectrometry (MS) has been considered as a unique tool for microscale enzyme assay and inhibitor screening. In this study, matrix metalloproteinase-9 (MMP-9) was selected as target enzyme due to its important role in tumor invasion and metastasis. In order to define the optimal MS parameters, a two level half fraction factorial experimental design was performed. A background electrolyte consisting of 20mM ammonium acetate (pH 6.8) and a sheath liquid of water-methanol (50:50, v/v) containing 0.05% formic acid at a flow rate of 4μl/min were selected. This system was operated in the positive ion mode with a detection-limit of 10nM for the MMP reaction product and provided 60 folds enhancement of sensitivity by using selected reaction monitoring detection compared with MS full scan mode, which significantly increased the detectability of the system and therefore reduced the enzyme reaction time in both off-line and in-line mode. Both electrophoretically mediated microanalysis and pressure mediated microanalysis combined with MS detection were investigated for MMP inhibitor screening. Good repeatability (RSD of peak area and migration time were lower than 5.0%) and linearity (R2>0.996) were obtained for both in-capillary approaches. Several tetracycline antibiotics and natural products were selected to test the system. The results indicated an agreement on the ranking of inhibitory potency for both in-capillary approaches. © 2013 Elsevier B.V. Source


Chen R.,China Pharmaceutical University | Chen M.,Jiangsu Provincial Institute for Food and Drug Control | Cai M.,Jiangsu Provincial Institute for Food and Drug Control | Wang Y.,China Pharmaceutical University | Wang Y.,Jiangsu Provincial Institute for Food and Drug Control
Zhongguo Zhongyao Zazhi | Year: 2011

Objective: To establish a HPLC method with the relative correction factors (RCFs) for quantification of five critical related substances (A, B, C, D and E) in puerarin and its injection. Method: Taking puerarin as the internal standard, corresponding RCFs of the critical related substances were determined respectively. According to their RCFs, simultaneous determination of five related substances in puerarin and its injection was performed. The method was evaluated by comparison the quantitative results of external standard method and the method with RCFs correction. Result: There were no significant differences in the results of five critical related substances in 38 batches of puerarin and its injection by external standard method and the method with RCFs correction. Conclusion: The HPLC method with RCFs was validated to be accurate and can be successfully applied to determine the critical related substances in puerarin and its injection. Source


Yuan Y.-Z.,Jiangsu Provincial Institute for Food and Drug Control | Yuan Y.-Z.,Catholic University of Leuven | Zhang M.,Jiangsu Provincial Institute for Food and Drug Control | Fan X.-L.,Jiangsu Provincial Institute for Food and Drug Control | And 5 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2013

The characterization of impurities present in vertilmicin by liquid chromatography (LC) coupled with mass spectrometry (MS) is described. A reversed phase (RP)-LC method using a C18 column resistant to basic pH with an alkaline (pH 11) aqueous mobile phase was developed and coupled to MS with an electrospray ionization (ESI) source in the positive ion mode which provides MSn capability. In total, 18 impurities were detected in a commercial sample. Eleven impurities described in this work were newly identified. © 2013 Elsevier B.V. Source

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