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Updated: Jan 14, 2026

Application and Methodology of the Non-destructive 19F Time-domain NMR Technique to Measure the Content in Fluorine-containing Drug Products
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Application and Methodology of the Non-destructive 19F Time-domain NMR Technique to Measure the Content in Fluorine-containing Drug Products

Published on: August 22, 2017

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齐普罗夫洛克萨 (,和形式):通过振动和固态NMR光谱仪进行实验和DFT表征

Filipe C D A Lima1, Arthur P Camargo2, Fabrice Leroux3

  • 1Instituto Federal de Educação, Ciência E Tecnologia de São Paulo (IFSP), Campus Matão, Av. Stefano D'avassi, 625, Matão, SP CEP 15991-502, Brazil.

ACS omega
|October 27, 2025
PubMed
概括

这项研究确定了齐普罗夫洛素 (Cipro) 独特的光谱指纹,包括其复,阴离子和阳离子固体形式. 这些发现有助于对这种重要的抗生素进行药物分析和环境监测.

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¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR

The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.
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Infrared spectroscopy is primarily used to determine the types of bonds and functional groups. In carboxylic acid derivatives, a typical carbonyl bond absorption is observed around 1650–1850 cm−1. For esters, the absorption is recorded at around 1740 cm−1, while acid halides show the absorption at about 1800 cm−1. Another acid derivative, the acid anhydrides, exhibit two carbonyl absorption around 1760 cm−1 and 1820 cm−1, arising from the symmetrical and...
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Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
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While α protons of carboxylic acids absorb at 2–2.5 ppm, β protons absorb further upfield.
Carboxylic acids are easily identified by dissolving them in deuterium oxide, which results in a rapid exchange of the acidic protons with deuterium. This leads to the...
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