NMR and mass spectrometric characterization of vinblastine, vincristine and some new related impurities – Part I

Determining gas compositions from live well fluids on a drilling rig is critical for real time formation evaluation. Development and utilization of a reliable mass spectrometric method to accurately characterize these live well fluids are always challenging due to lack of a robust and effectively selective instrument and procedure. The methods currently utilized need better calibration for the characterization of light hydrocarbons (C1–C6) at lower concentrations. The primary goal of this research is to develop and optimize a powerful and reliable analytical method to characterize live well fluid using a quadruple mass spectrometer (MS). The mass spectrometers currently being used in the field have issues with detection, spectra deconvolution, and quantification of analytes at lower concentrations (10–500 ppm), particularly for the lighter (<30 m/z) hydrocarbons. The objectives of the present study are thus to identify the detection issues, develop and optimize a better method, calibrate and QA/QC the MS, and validate the MS method in lab settings. In this study, we used two mass spectrometers to develop a selective and precise method to quantitatively analyze low level lighter analytes (C1–C6 hydrocarbons) with masses <75 m/z at concentrations 10–500 ppm. Our results suggest that proper mass selection like using base peaks with m/z 15, 26, 41, 43, 73, and 87, respectively, for methane, ethane, propane, butane, pentane, and hexane can help detect and accurately quantify hydrocarbons from gas streams. This optimized method in quadrupole mass spectrometer (QMS) will be invaluable for early characterization of the fluid components from a live hydrocarbon well in the field in real time.

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Isolation and mass spectrometric characterization of an oxidized form of vasostatin I, anN-terminal chromogranin A-derived protein, from bovine chromaffin cells

Journal of Mass Spectrometry ◽

10.1002/jms.1190301113 ◽

1995 ◽

Vol 30 (11) ◽

pp. 1599-1604 ◽

Cited By ~ 8

Author(s):

L. Dillen ◽

X. Y. Zhang ◽

M. Claeys ◽

F. Liang ◽

W. P. De Potter ◽

...

Keyword(s):

Chromogranin A ◽

Chromaffin Cells ◽

Mass Spectrometric ◽

Bovine Chromaffin Cells

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Identification, Characterization, and Quantification of Impurities of Safinamide Mesilate: Process-Related Impurities and Degradation Products

Journal of AOAC International ◽

10.5740/jaoacint.16-0218 ◽

2017 ◽

Vol 100 (4) ◽

pp. 1029-1037 ◽

Cited By ~ 1

Author(s):

Liang Zou ◽

Lili Sun ◽

Hui Zhang ◽

Wenkai Hui ◽

Qiaogen Zou ◽

...

Keyword(s):

Degradation Products ◽

Hplc Method ◽

Formation Mechanisms ◽

Stability Indicating ◽

Related Impurities ◽

Related Substances ◽

Water Ph ◽

Bulk Drug ◽

First Time

Abstract The characterization of process-related impurities and degradation products of safinamide mesilate (SAFM) in bulk drug and a stability-indicating HPLC method for the separation and quantification of all the impurities were investigated. Four process-related impurities (Imp-B, Imp-C, Imp-D, and Imp-E) were found in the SAFM bulk drug. Five degradation products (Imp-A, Imp-C, Imp-D, Imp-E, and Imp-F) were observed in SAFM under oxidative conditions. Imp-C, Imp-D, and Imp-E were also degradation products and process-related impurities. Remarkably, one new compound, identified as (S)-2-[4-(3-fluoro-benzyloxy) benzamido] propanamide (i.e., Imp-D), is being reported here as an impurity for the first time. Furthermore, the structures of the aforementioned impurities were characterized and confirmed via IR, NMR, and MS techniques, and the most probable formation mechanisms of all impurities proposed according to the synthesis route. Optimum separation was achieved on an Inertsil ODS-3 column (250 × 4.6 mm, 5 μm), using 0.1% formic acid in water (pH adjusted to 5.0) and acetonitrile as the mobile phase in gradient mode. The proposed method was found to be stability-indicating, precise, linear, accurate, sensitive, and robust for the quantitation of SAFM and its process-related substances, including its degradation products.

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