Flow syringe

Type constant flow twin reciprocating constant flow syringe type constant pressure pneumatic amplifier... 

Capillary 3 2 On-line capillary, LightPipe 0.002 or none Special <1 Split flow, Syringe pump 20... 

Load one of the stopped-flow syringes with Stock 1 and the other with the Reaction 1 solution from Table 4.7. 

Fig. 4. Schematic representation of a septumless on-flow syringe injection port.

Hitherto syringe pumps have not been used extensively in FI systems however, a recently developed sinusoidal flow syringe pump designed by Ruzicka et al.[ 1] has shown promise in a number of applications, and will be described here briefly. 

Place the vesicle suspension containing 1-2 mM lipids in buffer A in the second stopped-flow syringe. 

Fill the stopped-flow syringes with the appropriate solutions A 1-3 pM retinal-IRBP complex at the desired retinal/IRBP mole ratio B Suspension of PY-PC-containing vesicles (1-2 mM lipids)... 

Figure C3.1.2. Stopped-flow apparatus with motor-driven syringes. Syringe plungers force tire reactants A and B tlirough a mixing chamber into a spectral cell. Kinetic data collection begins when tire effluent syringe plunger is pushed out to contact an activation switch, about a millisecond after tire initiation of mixing. (Adapted from Pilling M J and Seakins P W 1995 Reaction Kinetics (Oxford Oxford University Press)...

Samples and calibration standards are prepared for analysis using a 10-mL syringe. Add 10.00 mL of each sample and standard to separate 14-mL screw-cap vials containing 2.00 mL of pentane. Shake vigorously for 1 min to effect the separation. Wait 60 s for the phases to separate. Inject 3.0-pL aliquots of the pentane layer into a GC equipped with a 2-mm internal diameter, 2-m long glass column packed with a stationary phase of 10% squalane on a packing material of 80/100 mesh Chromosorb WAW. Operate the column at 67 °C and a flow rate of 25 mL/min. 

At the time of the solvent methanol experiments a metering pump was used. In some experiments the pulsating action of the pump can be disturbing, so a high-pressure syringe-type pump can be used. Since mass flow controllers are available now, the combination of a gas-pressurized feed tank on an electronic scale for liquid level indication and a mass flow controller seems to be a good choice. Both the feed tank and separator can be heated or cooled. In the case of the solvent methanol experiments. 

The basic difference between this type of valve and the normal external loop sample valve is the incorporation of an extra port at the front of the valve. This port allows the injection of a sample by a syringe directly into the front of the sample loop. Position (A) shows the load position. Injection in the front port causes the sample to flow into the sample loop. The tip of the needle passes through the rotor seal and, on... 

Figure 2.20 Schematic representation of the set-up used for on-line exti action-GC VI and V2, valves PI and P2, syringe pumps L, sample loop CC flow, countercunent flow CT, cold ti ap. Reprinted from Journal of High Resolution Chromatography, 16, H. G. J. Mol et ai, Use of open-tubular tapping columns for on-line exti action-capillary gas cluomatography of aqueous samples , pp. 413-418, 1993, with permission from Wiley-VCH.

The types of pumps used for HPLC can be divided into two categories constant-pressure pumps (e.g. the inexpensive gas-displacement pump) and the constant-volume type (e.g. the reciprocating and syringe pumps). The most commonly used pumps in HPLC are the single- or multi-head reciprocating type. The former delivers the flow as a series of pulses which must be damped... 

After inserting a needle into a vein for IV drug administration, pull back the syringe barrel. Blood should flow back into the syringe. After a backflow of blood is obtained, it is safe to inject the drug. 

When administering a drug into a vein by a venipuncture, tiie nurse should place a tourniquet above the selected vein. It is important to tighten the tourniquet so that venous blood flow is blocked but arterial blood flow is not. The nurse should allow the veins to fill (distend) and then should pull tiie skin taut (to anchor the vein and the skin) and insert tiie needle into tiie vein, bevel up, and at a short angle to tiie skin. Blood should immediately flow into the syringe if tiie needle is properly inserted into the vein. 

A syringe pump was used for the addition of acid chloride in order to achieve a steady flow rate. The tip of the syringe needle (gauge 20) was submerged in the reaction mixture. Dropwise addition of trimethylacetyl chloride at 0-5°C resulted in the immediate formation of a precipitate. 

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