Briefly describe the applications ESR spectral studies.
Application of ESR to Measure Oxygen Free Radicals
The nitrone compound used for ESR spin-trapping can be used to detect (and measure) oxygen free radicals such as O2•− and HO•. Meanwhile, nitroso compounds are mainly used to detect carbon radicals. Desirable characteristics of spin-trapping reagents include high solubility and stability in water, and the ability to interact with free radicals. Furthermore, high reactivity is required to observe the formation of free radicals, while low reactivity is needed to measure elimination activity. It is also desirable that the resulting spin adduct is stable for a relatively a long time and that the spectrum can be easily analyzed.
In our initial studies in 1985, we used DMPO, a high quality agent, as the spin-trapping agent [13], and was supplied from domestic chemical companies. We found that early batches of DMPO imported from other countries had low purity and reacted with blood and living tissues, Moreover, carbon-based radicals derived from the reagent were observed. Since then, domestically produced DMPO has been widely used.
Since 1976, many researchers have used DMPO for in vitro studies of living cells, particularly neutrophils. Notably, DMPO is easy to handle for ‘beginners’, is relatively cheap and is a stable reagent. The main advantage of DMPO is that it is easy to analyze ESR spectra. However, DMPO
__________ _________ ____ ________ _______ _______ _______ ________ ________ ______ ____.
________ _________ ___ _______ ________ ____.
____ ________ _______ _____ ____ __________ ________ _____ __________ ___ _______.
_____ ________ ________ ______ _______ _______ ______ _____ _________.
_______ ________ _______ ___ _______ _________ ____ _________.
______ ___ ___ __________ _____ ________.
________ ___ ______ ____ ____.
______ ___ _________ _________ ____ _________ _______ ___ _______.
______ _____ ________ _______ ____ _____ ________ _____.
___ _______ ________ _____ ______ ___ __________ ___ _______ ____.
_______ _______ ______ ________ _______ _________ _____ ____ ________ __________ ______ ____.
______ ________ ___ ______ ____ ____ _____ _________ _____ _____.
_____ ______ _________ __________ ____ ___ ___ ________.
_____ ________ _______ ________ ____ ________ ___.
______ ____ ________ ______ ___ _____.
___ ________ _____ _____ ________ ____ ___ ______ __________.
____ ________ ____ ________ ______.
__________ _________ ___ ____ _________ _________.
________ ___ _____ ____ _________ _____ ______ _________ _____ _____ _____ ___.
__________ _____ _________ __________ ____ ________ ________ ___.
________ _________ _______ _________ ___ ______ _______ ___ _____ ________ __________ ____.
________ _________ ____ ____ __________.
_______ ________ _______ _____ _________.
_______ ____ ___ ___ ___ ________ ____ ___ __________ _____ _______.
__________ ___ ___ _________ ______ _______ ___ _______ _____ _________ _______.
______ _______ _____ _____ _______ ______ ____ _____ ________ __________ _____ ___.
______ ___ _______ _______ _____ __________ _____ _____ ____ ____.
_____ _____ _________ ________ __________ _______.
_______ __________ __________ ______ _______ _____.
________ ________ ___ _____ ________ ____.
_______ __________ _________ _________ __________ ________ ___.
____ __________ _________ __________ ________ _____ ___ ___.
_____ __________ ______ _________ _______ __________ _______ ______ ____ ____.
________ _____ _____ __________ ___ _________ ______ ______ ____ ____ _____ _______.
_________ __________ ______ ____ _____.
_______ ______ _____ ________ _____ ________ _______ ___.
___ ______ __________ _____ __________ ________ ___ __________ ____.
___ _______ ______ _______ ________ ___ ____ _______ _____ _____ ____ _______.
_______ _______ _____ _____ ______ __________ ______ _____ ___.
______ __________ _______ _________ ____ _______ _______ _______ ________.
____ _____ ___ __________ _____ ___ ______ ___.
___ ______ _________ ___ ____ _______ ____ _________ ______ ___ ___.
__________ ______ ______ _____ _____ ______ _____ _______ _______ ________ ___.
________ _____ ___ ___ ____ _____ _________ ________ ___ ___ _______.
_________ _________ _______ ______ ____ _______ ________ ____ ____ ______ _______ ____.
__________ ____ _______ __________ ________ _____.
_________ ________ ______ _______ _____ ________ ____.
_______ _________ ___ _________ _________ ____.
____ ________ ____ _________ ________.
______ _____ ___ ____ _______ ________ __________ ________ _________ ________.
____ _____ ________ __________ ______ ______ ________ ____ ____ _______.
_____ _____ __________ ______ ___ ________ __________ ________ _____ _____ ______ ________.
___ ___ ____ _________ _____.
____ ______ __________ ___ ____ ____ ____ ______ ______ ____ ______.
______ __________ ________ ________ ________ _______ ______ _________.
___ _________ ___ ___ ______.
______ _________ ________ _______ _______ ______ ______ _______.
______ ___ ______ __________ ________.
_____ _____ _______ _________ _____ ____ ________ _______ _________.
_________ ____ __________ _____ _________ ___ _____.
________ ___ ___ ________.
- Solved Assignments
- Study Notes
- Guess Papers
- Question Papers
✓ Unlock up to 60% of the answer
✓ No payment required
Discuss the 1H-NMR spectrum of methyl acetate.
Briefly describe the applications ESR spectral studies.
Draw and explain the normal modes of vibration of water molecule.
Give the selection rules and the schematic diagram of the vibration-rotation
Raman spectrum of a diatomic gas.
Derive the expression
Why cannot a glass cell be used for IR spectroscopy?
What is Born-Oppenheimer approximation? Explain using a suitable diagram.