Background signals

The nomesonant background prevalent in CARS experiments (discussed above), although much weaker than the signals due to strong Raman modes, can often obscure weaker modes. Another teclmique which can suppress the nonresonant background signal is Raman induced Kerr-efifect spectroscopy or RIKES [96, 97]. 

Stop must be used to prevent photons from the plasma flame reaching the ion collector, which would produce a spurious high background signal. 

The optimal analytical GDMS instrument for bulk trace element analysis is the one providing the largest analytical signal with the lowest background signal, the fewest problems with isobaric interferences in the mass spectrum (e.g., the interference of with Fe ), and the least contamination from instrument com-... 

Bleeding An appearance of a background signal from a chromatographic system, caused by the stationary phase or contamination of the inlet system. The column bleed usually increases with increasing column temperature. 

It is likely that the answers to these questions will come only from more selective and sophisticated experiments than have been done hitherto, although some useful directions have been established. The use of high-sensitivity electron spin resonance for the study in situ of anticipated radical species will likely be possible, if the background signals from other radiation-produced species are not too intense. Studies of the chemistry of implanted atoms and ions in solid organometallic substrates will make it possible to start with totally unbound atoms which suffer no Auger ionization and thus to simulate the extreme of the total recoil. Careful studies of the thermal annealing effects, especially in the presence of reactive atmospheres, will... 

Automatic scanning routines coid>ined with video Integration allow the correct determination of the baseline under each peat. During the scan mode the background signal before and after each spot is acquired and used to compute the baseline position. The baseline in TLC may vary at different positions in the... 

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