Multi-wavelength

BE-3116 Multi-Wavelength Shearography Dr. H. R. Schubach Ettemayer Qualltatsaleherung... 

Lyzenga, G.A., and Ahrens, T.J. (1979), Multi wavelength Optical Pyrometer for Shock Compression Experiments, Rev. Sci. Instrum. 50, 1421-1424. 

There are two types of UV detector the fixed wavelength detector and the multi-wavelength detector. A diagram of a fixed wavelength UV detector is shown in figure 5. 

A diagram of the Multi-Wavelength Dispersive Detector is shown in figure 7. 

The performance of both types of multi-wavelength detectors are very similar and typical values for their more important specifications are as follows ... 

Dubin, A. Application of multi-wavelength spectroscopy to analysis of amniotic fluid bilirubin, in Amniotic Fluid. Natelson, S. Scommegna, A. and Epstein, M. D., ed. John Wiley, N. Y. (1974) pp. 191 - 197. 

B.G.M. Vandeginste, R. Essers, T, Bosman, J. Reijnen and G. Kateman, Three-component curve resolution in HPLC with multi wavelength diode array detection. Anal. Chem., 57 (1985) 971-985. 

Tam, K. Y. Takacs-Novak, K., Multi-wavelength spectroscopic determination of acid dissociation constants A validation study, Anal. Chim. Acta 434, 157-167 (2001). 

Tam, K. Y., Multi wavelength spectrophotometric resolution of the micro-equilibria of a triprotic amphoteric drug Methacycline, Mikrochim. Acta 136, 91-97 (2001). 

Most compounds can be detected directly as they are able to produce a direct analytical signal. Photometric detection, especially UV (including diode array and multi-wavelength UV detection) is by far the most frequently applied detection technique. The application of mass spectrometry (MS) detection in CE is attractive as it can provide structural information [44]. Hologram-based refractive index detection [45] and electrochemical detection [46,47] were also reported. Conductivity [41,48-50] and amperometric [51,52] detection has shown to have advantages for the analysis of both organic and inorganic compounds. 

Among optical sensors, those based on fluorescence are of major interest because of their ability to use spectral and temporal information multi-wavelength measurements allow simultaneous detection of two or more analytes, and discrimination between analytes is possible by time-resolved measurements. Multiplex capabilities represent the main advantage of such sensors compared to electrochemical devices. 

Only multivariate (e.g. multi-wavelength) data are amenable to model-free analyses. While this is a restriction, it is not a serious one. The goal of the analysis is to decompose the matrix of data into a product of two physically meaningful matrices, usually into a matrix containing the concentration profiles of the components taking part in the chemical process, and a matrix that contains their absorption spectra (Beer-Lambert s law). If there are no model-based equations that quantitatively describe the data, model-free analyses are the only method of analysis. Otherwise, the results of model-... 

The quality of the chromatographic procedure or parts of it can be optimized, for instance by using a multi-wavelength detector or a mass spectrometer. 

Multi-wavelength aerosol Scatterometer Particles density and optical... 

Abstract. A multi-wavelength, multi-sensor Look-Up-Table (LUT) algorithm has been developed to retrieve information about stratospheric aerosols from satellite-based observations of particulate extinction. Specifically, the LUT algorithm combines extinction measurements from SAGE n with similar measurements from the CLAES instrument, and uses the composite spectra in month-latitude-altitude bins to retrieve values and uncertainties of particle effective radius, surface area, volume and size distribution width. 

J Vindevogel, R Szucs, P Sandra, L Verhagen. Analysis of beer iso-ar-acids by micellar electrokinetic chromatography and multi-wavelength UV detection. J High Res Chromatogr 14 584-586, 1991. 

---