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Liu M.,Peking University | Liu M.,Shijiazhuang Yiling Pharmaceutical Co. | Zhao S.,Shijiazhuang Yiling Pharmaceutical Co. | Wang Y.,Shijiazhuang Yiling Pharmaceutical Co. | And 4 more authors.
Journal of Chromatographic Science | Year: 2014

A practical method using ultra-fast liquid chromatography in tandem with quadrupole time-of-flight mass spectrometry combined with dynamic background subtraction technology was developed for the rapid separation and identification of the complicated constituents in the Shensong Yangxin capsule (SSYX). The chromatographic separation was performed on a C18 column (2.1 × 100 mm, 2.6 μm) with a gradient elution program using methanol and 0.1% formic acid aqueous solution as the mobile phase at a flow rate of 0.4 mL min21. Accurate mass measurements of the molecular ions in the full scan and the characteristic fragment ions triggered by information-dependent acquisition provided reliable identification criteria. Thus, 99 compounds, including saponins, phenolic acids, tanshinones, lignans, terpenoids, alkaloids and flavonoids, were unambiguously or tentatively identified in 40 min by comparing their retention times and accurate mass measurements for each molecular ion and its subsequent fragment ions with those of authentic standards or literature data. Simultaneously, all the compounds were further assigned to the individual raw materials. In conclusion, these results will provide a basis for quality control and further study of SSYX, and the proposed technique based on high-resolution mass spectrometry would be expected to be adaptable to the analysis of complicated constituents in various complex matrices. © The Author 2014. Published by Oxford University Press. All rights reserved. Source

Liu J.-X.,CAS Beijing National Laboratory for Molecular | Zhang Y.-W.,CAS Beijing National Laboratory for Molecular | Yuan F.,CAS Beijing National Laboratory for Molecular | Chen H.-X.,Shanghai AB Sciex Analytical Instrument Trading Co. | Zhang X.-X.,CAS Beijing National Laboratory for Molecular
Electrophoresis | Year: 2014

A lab prototype CE-nanospray-MS platform with a high sensitivity porous sprayer was successfully applied in differential identification of Rhizoma coptidis in this paper. To obtain a stable and reliable nanospray, detailed optimizations about emitter geometry, buffer composition, emitter position, and spray voltage, as well as emitter cleanliness were discussed. Results showed that the reproducibility and sensitivity for separations of alkaloid standards were satisfactory using CE-nanospray-MS, which were also compared to ultra-HPLC (UHPLC)-MS. Their signal responds were at the same order of magnitude (intensities: 0.8 - 1.5 × 108 vs. 3.8 - 6.2 × 108), even though a 2 nL injection for CE was 2500-fold lower than UHPLC (5 μL injection). The absolute LOD results of CE-MS showed a remarkable superiority (18-24 fg), equal to 1000-fold lower than that of UHPLC-MS. Principal component analysis (PCA) of adulterated R. coptidis showed that this protocol had the ability to profile and qualify complex herb medicines, which also created a great potential for evaluation and qualification of rare and valuable Chinese medicines in future. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Fang H.,Peking Union Medical College | Yu S.,Peking Union Medical College | Cheng Q.,Peking Union Medical College | Cheng X.,Peking Union Medical College | And 5 more authors.
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2016

Vitamin D plays important roles in skeletal metabolism and many other diseases, including chronic renal failure, hypoparathyroidism, sarcoidosis and rickets. 1α,25-dihydroxy vitamin D (1α,25(OH)2D), the active form of vitamin D, exhibits an extremely low serum concentration, which makes its quantification very challenging. High performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) is considered to be the "gold standard" for the determination of these chemicals, which are found in low concentrations in the serum, but conventionally, it needs tedious sample pretreatment procedures, such as solid phase extraction and derivatization. Herein, we describe a simple and rapid HPLC-MS/MS method for the simultaneous quantification of 1α,25-dihydroxy vitamin D3 (1α,25(OH)2D3) and 1α,25-dihydroxy vitamin D2 (1α,25(OH)2D2). The analytes were extracted from the matrix by liquid-liquid extraction, centrifuged to dryness and reconstituted with 75% methanol. Lithium acetate was employed to improve the ionization efficiency of 1α,25(OH)2D. The assay was sensitive with a low limit of quantitation of 10.0 pg/mL for both 1α,25(OH)2D3 and 1α,25(OH)2D2 using a 0.5 mL sample aliquot. Linearity was obtained over the range of 10.0 pg/mL to 500 pg/mL. Both the inter-assay and intra-assay precisions were <15%, and the analytical recoveries were within 100 ± 5%. The performance evaluation of this assay demonstrated that it was a practical, sensitive and specific method for measuring the serum 1α,25(OH)2D3 and 1α,25(OH)2D2 concentrations. © 2016 Elsevier B.V. Source

Yuan F.,CAS Beijing National Laboratory for Molecular | Zhang X.-H.,CAS Beijing National Laboratory for Molecular | Nie J.,CAS Beijing National Laboratory for Molecular | Chen H.-X.,Shanghai AB Sciex Analytical Instrument Trading Co. | And 2 more authors.
Chemical Communications | Year: 2016

A newly developed sheathless interface for capillary electrophoresis-mass spectrometry, using a porous tip sprayer, was first applied for highly sensitive determination of cytosine modifications. The system performed well in identification and quantification of both 5-methylcytosine and 5-hydroxymethylcytosine using only 125 pg (∼20 cells) genomic DNA samples. © The Royal Society of Chemistry 2016. Source

Chen X.,ShenYang Agricultural University | Jia Y.,Shanghai AB Sciex Analytical Instrument Trading Co. | Ji M.,ShenYang Agricultural University
Chinese Journal of Chromatography (Se Pu) | Year: 2015

A method for rapid screening and confirmation of 205 pesticide residues in rice was developed by combining QuEChERS and high performance liquid chromatography-triple quadrupole-linear ion trap mass spectrometry (LC-Q-TRAP/MS). The rice samples were extracted with acetonitrile, and then cleaned up with primary secondary amine (PSA), anhydrous magnesium sulfate (MgSO4) and C18 adsorbent. Finally, the samples were detected by LC-Q-TRAP/MS in multiple reaction monitoring with information-dependent acquisition of enhanced product ion (MRM-IDA-EPI) mode followed with database searching. A total of 205 pesticide residues were confirmed by retention times, ion pairs and the database searching using EPI library, and quantified by external standard method. All the pesticides showed good linearities with linear correlation coefficients all above 0. 995. The limits of quantification (LOQs) for the 205 pesticides were 0. 5-10. 0 μg/kg. The average recoveries of the 205 pesticides ranged from 62. 4% to 127. 1% with the relative standard deviations (RSDs) of 1. 0% -20. 0% at spiked levels of 10 μg/kg and 50 μg/kg, and only 20 min were needed for the analysis of an actual rice sample. In brief, the method is fast, accurate and highly sensitive, and is suitable for the screening and confirmation of pesticide residues in rice. Source

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