Multireflection cell

Salimi-Moosavi, H., Jiang, Y., Lester, L., McKinnon, G., Harrison, D.J., A multireflection cell for enhanced absorbance detection in microchip-based capillary electrophoresis devices. Electrophoresis 2000, 21(7), 1291-1299. 

Figure 4.3-19 FT-Raman spectrum of air at ambient pressure in a multireflection cell. Recording time 240 min., resolution 1 cm ia.ser power 380 mW at 1064 nm (Bruker, 1993).

Wang T, Aiken JH, Huie CW, Hartwick RA (1991) Nanoliter-scale multireflection cell for absorption detection in capillary electrophoresis. Anal Chem 63 1372-1376 Schmidt O, Bassler M, Kiesel P, Johnson NM, Doehler GH (2006) Guiding light in fluids. Appl Phys Lett 88 151109... 

Figure 3 High-sensitivity detection cells for LlV-Vis absorbance CE detectors (A) Z-cell (B) bubble cell and (C) multireflection cell.

SIA manifold for carbon speciation in bathing waters. BTB bromothymol blue indicator Detector spectrophotometer (Xmax = 611 nm) Detector (MRC) multireflection cell coupled to light-emitting diode (Xmax = 660 nm) HC holding coil RC reaction coil SV selection valve. 

FIGURE 30-5 Three types of cells for improving the sensitivity of absorption measurements in CE (a) a 3-mm z cell, (b) a 150-pm bubble cell, (c) a multireflection cell. 

Ito et al. [73] examined the micellization of fluorocarbon-hydrocarbon hybrid surfactants by Raman spectroscopy. The spectrometer was equipped with a multireflection cell and an optical-fiber light-collecting device [74]. The Raman spectra were obtained at high surfactant concentrations above the cmc, because the Raman intensity below cmc was too weak to be measured. 

Fig. 6. Cells used in various electro-optic experiments. In (a) the field is transverse to the light path as for birefringence and dichroism experiments, (b) is the multireflecting cell for electric dichroism. In (c) the multi de cells are also arranged in longitudinal array for optical rotation experiments, (d) are light scattering cells with hmizontal and vertical electrodes as shown...

Fig. 1 Diagram showing a planar multireflection absorbance cell. Aluminum mirrors thick lines) were coated above and below a channel. The narrowest region inside the cell is the fluid flow path (Reprinted from [15] with permission of Wiley-VCH). i (1,2,3,4) refers to different medium 0, is the angle within the medium i with respect to the surface normal h is the thickness of the medium i li is the longitudinal distance in each of medium and f = hi tan (0i) L is the total longitudinal travel for once reflection n the total number of reflections...

For the absorbance-based detectors, alternative cell geometries have been designed to extend the optical pathlength such as the Z-shaped cells, bubble cells, rectangular cells, and multireflection capillaries. Although manufacturing and manipulation of these special cells can pose a few operational problems, sensitivity enhancement of tenths of fold have been reported. The determination of the herbicide metribuzin and its major conversion products in soil is an example of the use of bubble cells, whereas the UV-detection of derivatized carbonyl compounds in rain is an example of the use of Z-shaped cells in environmental analysis. 

Fig. 3.12. Optical path of an infrared microspectrometer with a reflecting microscope in the sample beam and a multireflection gas cell in the reference beam. (Blout and Abbate, 1955.)...

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