Nuclear magnetic resonance spectrometer operation

The C-NMR spectrum ofindinavir sulfate, shown in Figure 13, was obtained using a Bruker Instruments model AMX-400 nuclear magnetic resonance spectrometer operating at a frequency of 100.55 MHz as an approximate 4.16 % w/v solution in deuterium oxide. The 67.4 ppm resonance of dioxane was used as an external reference standard. Peak assignments are found in Table 8, and make use of the numbered structural formula given previously [11]. 

Radio and TV broadcasts use radio frequency radiation. In addition, nuclear magnetic resonance spectroscopy, which causes transitions between nuclear spin states, uses radiation from this region. One typical NMR spectrometer operates at 2 X 108 Hz or 200 MHz (1.9 X 10 5 kcal/mol or 8 X 10 s kJ/mol). NMR spectroscopy is discussed in Chapter 14... 

The proton nuclear magnetic resonance spectrum of lomefloxacin mesylate obtained in D2O at 25° C is given in Figure 5 (9). The spectrum was obtained on a Bruker AM-500 NMR Spectrometer operating at 500.13 MHz and was referenced to external TSP [3-(trimethylsilyl)propionic-2,2,3,3-d4 acid]. The chemical shifts and spectral assignments are provided in Table 2 (9,10). The effect of increasing concentrations of Al3+ on the... 

The mass spectrometer is now widely accepted as a crucial analytical tool for organic molecules in the pharmaceutical industry. Although usually treated as a spectroscopic technique, it does not rely on the interaction with electromagnetic radiation (light, infrared, etc.) for the analysis. Rather it is a micro-chemical technique relying on the production of characteristic ions in the gas phase, followed by the separation and acquisition of those ions. By its operation, it destroys the sample unlike other techniques, such as nuclear magnetic resonance (NMR), infrared (IR) and Raman/UV spectroscopies. Nonetheless, mass spectrometry is so sensitive that molecular weight and structural information can be provided on very small samples (attomolar (10" molar) quantities). 

We used AG of molecular weight (M) 40,000, oxidized forms with AG (M = 22,000), and (M = 4,000). Modified compounds were synthesized using INAH (analytically pure). The INAH and polysaccharides were reacted in water. The proton magnetic resonance (PMR) spectra in D O were recorded on a Bruker AM-300 spectrometer (operating fiecprency 300 MHz), nuclear magnetic resonance (NMR)... 

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