Sample inlets valve

Figure 9 Schematic diagram of typical six-port rotary injection valve at (a) filling and (b) emptying position. (1) Sample-loop inlet, (2) carrier inlet, (3) outlet to the flow cell, (4) sample-loop outlet, (5) outlet to waste, and (6) sample inlet.

Figure 4.5. Mass chromatograph. (A) Carrier A inlet (S) sample inlet (B) carrier B inlet (V) valve/trap system (C) chromatographic column (D) gas density detector (R) recorder.

Isolate vacuum pump by closing oven outlet valve and carefully admitting dried air into oven (by slowly opening air inlet valve fully), increasing the pressure inside oven until the door can be easily opened. Remove drying dish with sample and cool 30 min in a desiccator. 

Disposable pTAS will be ideal for medical use [14]. However, the high fabrication cost of sophisticated pTAS including micropumps and microvalves is a real problem. One of the basic components of medical pTAS taking this into account is illustrated in Fig. 2. A detector cell consists of micro sensors and a 3-way microvalve is placed at the sample inlet. Flow is controlled by a suction pump and an injection pump connected to the detector cell. The calibration solution flow is also controlled by an individual pump and a 3-way valve. In this system, only sample flow reaches the detector cell. The upper parts of the system are free from contamination and corrosion so that they can be reused many times, while the detector cell has to be disposed of. To realize this system, a 3-way microvalve which can handle whole blood is indispensable. A separable channel type microvalve whose channel part is disposable while actuator part is reusable is useful for the 3-way microvalve of the detector cell [15]. Mechanically fixed stack structures including disposable parts are useful in many medical pTAS. 

As a test reaction, the alkylation of benzene with dodecene was chosen. The batch reactor system consisted of a round-bottomed flask (slurry reactor) provided with a cooler, gas-inlet valve, and sampling exit. A magnetic stirrer equipped with a thermostat and a silicon oil bath were used to maintain the reaction temperature and ensure the homogeneity of reactants. The catalyst was weighed in the reactor and then benzene was added according to the proportion desired, followed by the addition of dodecene. 

Sample Inlet System. A detailed diagram of the inlet system is shown in Figure 2. All pipework on the system is 1/4-inch stainless steel tubing except where otherwise designated. Valves 1-10 are Vg-inch stainless steel Hoke valves with V-stems and Teflon packing. Valves 2, 4, 6, and... 

A mass spectrometer is used which is on-line with an IBM 1800 computer. This capability greatly simplifies the extensive calculations which are required. Prior to analysis of a sample(s), a silica gel column blank is analyzed to supply the computer with a spectrum which will subsequently be subtracted from each unknown sample. A blank corrects each set of four unknowns that were simultaneously run through the silica gel separation. In practice, column blanks are quite similar to one another, so a given blank can be used to correct other samples sets also. In each instance the entire fraction is charged to the spectrometer by introducing the sample with a gallium-sealed frit at room temperature and with the sample inlet system open to the vacuum pumps. After 3 min of pumping to remove most of the isooctane, the vacuum valve of the inlet system is closed, and the frit temperature is increased to 315 °G. This vaporizes the hydrocarbons from the frit, and the sample spectrum can be obtained. 

Experiments for pulse reaction on reduced KNiCa/ZSI catalyst were conducted with a gas sampling valve in a pulse microreactor, which was incorporated between the sample inlet and the column of gas chromatograph. FT-IR spectroscopic studies were performed in a quartz vacuum cell using self-supported wafers which were treated under vacuum or underwent the... 

Sequential injection analysis with lab-on-valve was conceived by Ruzicka in 2000 [84] as a progression of the sequential injection system towards downscaling. All components are integrated in a single unit mounted on a multi-position valve. The detector compartment is reduced and placed very close to the sample inlet, thus minimising the required volumes of sample, reagent and wash solution. 

The reactor used in temperature programmed desorption was a quartz reactor containing 0.2S g of catalyst. The desorption was done after reaction in situ at 120°C for either 5 or 24 hours and cooling in inert gas to room temperature. The heating rate was 0.5 K/s. The outflow was analyzed both by direct inlet into a mass spectrometer and by using a 12 sample positioning valve connected to a GC/MS. The inert gas (helium) doped with neon was used as an internal standard. 

Fig. 9.7.5 Details of integrated injector and injection plug generation on LC chip from NMRC, Cork, Ireland, (a) Schematic showing external valve connections to chip for fluid control, (b) Micrograph of on-chip injection loop made by sample inlet and outlet channels forming a double tee junction with the main separation channel,...

Fig. 16 Microfluidic genetic analysis (MGA) system, (a) Dyes are placed in the channels for visualization Scale bar. 10 mm). Domains for DNA extraction yellow), PCR amplification red), injection green), and separation blue) are connected through a network of channels and vias. SPE reservoirs are labeled for sample inlet ST), sidearm ( 4), and extraction of waste (EW). Injection reservoirs are labeled for the PCR reservoir PR), marker reservoir (MR), and sample waste (5W). Electrophoresis reservoirs are labeled for the buffer reservoir (BR) and buffer waste (BW). Additional domains patterned onto the device included the temperature reference TR) chamber and fluorescence alignment (FA) channel. The flow control region is outlined by a dashed box. Device dimensions are 30.0 x 63.5 mm with a total solution volume < 10 pL Scale bar. 10 mm), (b) Flow control region. Valves are shown as open rectangles. VI separates the SPE and PCR domains. V2 and V5 are inlet valves for the pumping injection, V3 is the diaphragm valve, and V4 is an outlet valve, (c) Device loaded into the manifold, (d) Intersection between SI and SA inlet channels, with the EW channel tapering to increase flow resistance Scale bar. 1 mm).

Figure 3.24. Mettler TA 2000 C ihermoanalyzer schematic diagram. I. furnace for regular gas atmosphere 2. furnace for corrosive gas atmospheres 3. inlet valve 4. needle valve 5, gas flow meter 6. pressure gauges 7. exhaust valve 8. shut-off valve 9, bypass valve 10. plate valve 11. fore-vacuum valve 12. diffusion pump 13. rotary pump 14, balance 15. sample cup holder.

Fig. 4.6.6. Six-port three-way sample injection valve. 1, eluent inlet 2, outlet to column 3, sample inlet 4, sample outlet 5, sample loop 6, rotor -, filling sample loop ., injecting sample.

Linearity check procedure. A pure gas cylinder of known purity is connected into the sample loop inlet. Evacuate the sample outlet manifold including sample loop to less than 1 mm Hg absolute pressure. Close the valve to the vacuum source and carefully open the sample metering valve to allow the gas sample to fill the sample loop up to the desired pressure as indicated by the manometer. Run the analysis by injecting the sample into the gas chromatograph. Then, repeat the same procedure for other partial pressures in recommended range. 

FIGURE 44.24 Channel structure with the sample inlet, S, and the hydrodynamically focusing buffer inlet, B, together with with the valve-less switching inputs G1 and G2. 

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