Micro flow cell

Micro Flow cell Microfluidizers Microgel theory Microgravity Microhardness... 

Figure 4.30 Electrochemical micro reactor, a diaphragm micro flow cell, applied to perform the cation flow method. Assembled device (left). Disassembled device showing the two compartments of the cell within the housings and the diaphragm (right) [67. ...

Reactor 30 [R 30] Electrochemical Diaphragm Micro Flow Cell... 

Reactor type Electrochemical micro flow cell Diaphragm material PTFE... 

The IBW of a standard system can be reduced to 30-40 jL by using shorter lengths of 0.005-0.007" i.d. tubing and a semi-micro flow cell (2-3 tL).i° Further reduction might involve a low dispersion micro-injector or a redesign of the autosampler. Table 4 summarizes the typical IBW and other instrumental requirements of various column types from conventional (4.6 mm), Fast TC, minibore (3 mm), narrowbore (2 mm) and microbore (1mm) to micro TC (<0.5mm) columns. Note that the dispersion... 

If a nonstandard flow cell snch as a semi-micro flow cell with a shorter path length is nsed, a label on the outside of the detector signifying the flow cell type and path length is recommended. 

Figure 25-19 Light path in a spectrophotometric micro flow cell One common cell with a pathlength of 1 cm has a volume of 8 iL Another cell with a 0.5-cm pathlength contains only 2.5 jiL...

The micro flow cell Golden Gate [125] can tolerate up to 66 bar at temperatures up to 200 °C. The cell volume amounts to 28 ml and fluidic interfaces are 1/16 in Swagelok capillary fittings. While the dimensions of the actual flow cell are only a few centimeters, the actual optical interface to a spectrometer consist of a macroscale table-top device with a clamping mechanism which positions the flow cell in the optical pathway. 

Shoji, S., Esashi, M., Micro flow cell for blood gas analysis realizing very small sample volume. Sensors Actuators B 1992, 8(2), 205-208. 

Absorption and Fluorescence Instrumentation. Absorption spectra were obtained using a Princeton Applied Research Corp. (PARC) Model 1208 polychromator, a Perkin-Elmer 8 yL absorption flow-cell and a 50 watt deuterium light source. Fluorescence spectra were obtained using a Farrand Mark 1 Spectrofluorometer (previously described (13)) and either a 10 iiL Farrand micro flow-cell, or a Precision Cells, Inc. (Model No. 8830) 20 yL flow-cell. A PARC Model 1254 SIT detector, having a UV scintillator, was mounted on both the absorption polychromator and fluorescence spectrofluorometer. Spectral coverage in the absorption and fluorescence modes was 60 and 115 nm, respectively. All absorption and fluorescence spectra were obtained in one second, i.e., 32 scans of the SIT target. 

The sample cell, attached to the IR microscope by means of an XY stage is a micro flow cell (See Figure 1). The ceil is manufactured completely of stainless steel. Sam-... 

Replace the detector flow cell with an optional semi-micro flow cell (2-5 pL)... 

Use an optional semi-micro flow cell for Fast LC or micro LC. Put label on detector front panel signifying the use of a nonstandard flow cell and pathlength. 

The electrolysis of sucrose was performed in a filter press cell (micro-flow cell, electro-cell AB) (Figure 21.19). The working electrode was platinum deposited electrochemically on a titanium plate. The counter electrode was a plate of stainless steel. The two compartments of the cell were separated by an ion-exchange membrane (Nation 423). A part of this membrane immersed in a saturated potassium sulfate permitted to connect by capillarity the MSE. The electrolyte in the cell was circulated by an external peristaltic pump (1 cm3 min-1) and passed through a reservoir (100 cm3). 

Table 21.1 classifies popular LC detectors according to several criteria for purposes of comparison. At the present time, LC detectors are generally less sensitive than GC detectors, which can detect picograms of material under good conditions. Most LC detectors provide only limited structural information. However, spectrophotometers fitted with micro flow-cells can be used to obtain a stop-flow ultraviolet-or visible-absorption spectrum of an LC peak trapped in the flow cell. On-line coupling of liquid chromatographs with mass or infrared spectrometers offers sophisticated, but indeed expensive, detection/identification methods. Such systems have been described in the literature, but are quite limited by the solvents that can be used in the chromatography step. 

Organic compounds that possess an ultraviolet- or visible-absorbing chromophore obey the Beer Lambert or Beer-Bouguer law of spectrophotometry. In what is generally termed molecular absorption spectrophotometry, a cuvette (in the case of stand-alone UV-vis spectrophotometers) or a micro-flow cell (in the case of flow through HPLC UV-vis detectors). We now proceed to derive the fundamental equation that relates absorbance as measured on an UV-vis HPLC detector to concentration because this relationship is important to the practice... 

It is seen from this relationship that when no radiation is transmitted, % T = 0 and A = 2, whereas if all ineident radiation is transmitted through the euvette or micro-flow cell, the % P = 100, all radiation is transmitted, and A = 0. The simple proportion between A and c forms the basis for TEQA using UV-vis-absorption HPLC detectors. 

The fluorescence HPLC detector (HPLC FL) is similar to the UV-absorp-tion HPLC detector (HPLC UV) in that a source of UV radiation is made incident to a micro-flow cell in whieh the chromatographically resolved analyte passes through. However, a photomultiplier tube (PMT) and associated optics are positioned at right angles relative to the incident UV radiation. Lakowicz has articulated just what molecular luminescence is (93) ... 

Paddon CA, Pritchard GJ, Thiemann T et al (2002) Paired electrosynthesis micro-flow cell processes with and without added electrolyte. Electrochem Commun 4 825-831... 

Electrosynthesis of phenyl-2- propanone derivatives from btmzyl bnunides and acetic anhydride in an unsupported micro-flow cell electrolysis process. Gretai Chem 9 20-22... 

Figure 3.6 Different FIA cell configurations (a) Wall-jet type cell (b) commercial thin layer flow cell (c) Plexiglass flow cell and (d) micro flow cell. Cells (a), (c), and (d) were built in the author s laboratory.

S Shoji and M Esashi, Micro flow cell for blood gas analysis realizing very small sample volume. 

Figure L (yoss section of the micro flow-cell showing the sensor array, the flow channel and the base plate.

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