Low-power irradiation

The principles behind MAP liquid-phase and gas-phase extractions are fundamentally similar and rely on the use of microwaves to selectively apply energy to a matrix rather than to the environment surrounding it. MAP gas-phase extractions (MAP-HS) give better sensitivity than the conventional static headspace extraction method. MAP-HS may also be applied in dynamic applications. This allows the application of a prolonged, low-power irradiation, or of a multi-pulse irradiation of the sample, thus providing a means to extract all of the volatile analytes from the matrix [477]. 

How does a spectrometer deliver this RF irradiation to the probe Compared to normal excitation pulses, which are very high-power and short ( 10 p,s) duration, decoupling requires low-power irradiation for the entire acquisition time (1-2 s). This is usually accomplished by having two separate sources of RF power, a broadband transmitter that can be... 

This traditional ID NMR experiment involves selectively decoupling a proton from its J coupling partners. This is accomplished by low-power irradiation at the frequency of the... 

According to lit. 24, the lack of enhancements in the NOE experiments is conclusive evidence for the C-12S stereochemistry. In fact, sizeable(3-5%)enhancements of the H-iP(equatorial) were observed in C-12S series compounds, 17-19 and 24-30 upon selective low-power irradiation of the proton signal due to H-12. In order to decide the stereochemistry of C-12,... 

Application of long-range selective proton decoupling using low-power irradiation has enabled the assignment of indirect coupling in the... 

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