Signal sensitivity

For SEC employing light scattering or viscosity detection it is often necessary to extrapolate the log M versus retention time data derived from the integration to account for the lack of signal sensitivity at one or another extreme of the distrihution. If the characteristics of the column are known to he linear... 

Lemaire R, Wisztorski M, Desmons A, et al. MALDI-MS direct tissue analysis of proteins improving signal sensitivity using organic treatments. Anal. Chem. 2006 78 7145-7153. 

Zhou X, Zhou J (2004) Improving the signal sensitivity and photostability of DNA hybridizations on microarrays by using dye-doped core-shell silica nanoparticles. Anal Chem 76 5302-5312... 

A simple alternative to direct detection of intrinsic protein fluorescence detection is the technique of indirect fluorescence detection proposed by Kuhr and Yeung.20 In this approach, the analysis buffer contains a fluorescent anion that produces a high background fluorescence signal. Nonfluorescent analyte anions displace the fluorescent species, producing a zone of reduced signal. Sensitivity in indirect fluorescence detection is determined by the dynamic reserve (ratio of signal... 

Figure 12-12 Proton-decoupled, 63.1 MHz, 13C spectrum of methylcy-clohexane at—110°. The upper right curve was taken with the signal sensitivity control turned up by a factor of 64. (Courtesy of Dr. F. A. L. Anet.)...

Signal-Sensitive and Responsive-Controlled Release Systems. 

In TERS microscopy and spectroscopy, the tip enhancement due to the SPP resonance plays the most essential role both for signal sensitivity and spatial resolution. However, the tip-enhancement effect is not the only one affecting Raman spectra. There coexist other interaction mechanisms between a metal tip and sample molecules, chemical interactions similar to SERS [120-122], and, in addition, mechanical interactions (see Sect. 5.4.1). The latter two interactions show up only when sample molecules are in a close vicinity of a tip. In the TERS system using a ccaitact mode AFM, an experimentally observed TERS spectrum is a complex combination of the contributions of these three interactions, which makes it difficult to interpret experimental TERS spectra. Therefore, elucidation and discrimination of the tip-sample interactions are of scientific and practical importance. This can be realized by measuring a tip-sample distance dependence of TERS, since those three interaction mechanisms have different dependencies on the tip-sample distance. The active control of the distance between the tip and sample is a unique feamre only possible in TERS not in SERS. Two system configurations, time-gated detection and timegated illumination, are described below. 

The UV detector, fluorescence detector, electrolytic detector, refractive index detector, and other detection systems must be checked for repeatability of response signal, sensitivity, and stability. 

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