Syringe pumps

One of the major sources of problems encountered in spin-coating hardware is the dispensing equipment. Frequently it has been recommended that the resist be dispensed directly from the bottle thereby avoiding all mechanical pumps, syringes, or additional filtering equipment. Provided the resist solution has been adequately filtered prior to dispensing, direct application from the bottle should yield the lowest defect films possible. 

An infusion control device (ICD) is a device that maintains a constant infusion rate in a gravity flow system (controller) or via a positive pressure pump. A positive pressure pump is a device that provides mechanical pressure (2-12 psi) to overcome the resistance to flow in the vessels. The types of positive pressure pumps are categorized according to how they deliver the solution and their degree of precision in the flow rate. Positive pressure pumps include peristaltic pumps, cassette pumps, syringe pumps, non-electiic or disposable pumps, and patient-controlled analgesic... 

From the last shown elution method, it is clear that the pump is a very important accessory for high-pressure liquid chromatography. There are three main types of pumps used in modern chromatographs membrane pumps reciprocating piston pumps syringe type pumps constant pressure pumps... 

Cartridge, 10 mL 2 Pumps, syringe, ISCO Model 260D... 

Bailey, L.C. Tang, K.T. Medwick, T. Stability of ceftriaxone sodium in infusion-pump syringes. Ajn.J.Hosp.Pharm., 1993, 50, 2092—2094... 

Figure 2.1-6 (a) Small-volume reciprocating pump head. Single ball check valves are used for controlling the air/fluid flow (Superpressure Inc.), (b) Laboratory scale positive displacement pump (syringe pump High Pressure Equipment Co.). 

Multiport injection valve used in HPLC to introduce the sample onto the column, the valve has six ports, two connected to a sample loop and one each to the column, pump, syringe loading port and waste. The sample is first loaded into a sample loop, usually 5-20 pi capacity, with the valve in the bypass mode rotation of the valve diverts the solvent through the sample loop whereupon the sample is swept onto the column. Sample size repeatability is better than 1%. The valves are also used for multicolumn switching. 

Depending on the principle of operation, we shall distinguish four categories of pumps pneumatic pumps, syringe-type pumps, reciprocating pumps and hydraulic amplifier pumps. The principles of operation of these four types are different and will be described briefly. 

Electrospinner is composed of four main components the pump, syringe and spinneret, power supply, and the collector as illustrated in Fig. 1 (Mumgan and Ramakrishna 2006). 

Determination of the spike mass flow is the most crucial point in on-line isotope dilution MS. Biased mass flow values will have the most influence on the expanded uncertainty of the final result. Two methods of mass flow assessment have been described in the literature. The first method determines the mass flow gravimetrically. The make-up flow /gp can be supplied by a pump able to deliver a precise and accurate flow (micro-HPLC pump, syringe pump) or by self-aspiration of the nebuliser. /gp is assessed gravimetrically by repeated measurement. The spike mass flow My t) is calculated as follows ... 

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. 

When 5.00 mL of ether has been delivered by the syringe pump, the pump is shut off The reactor is allowed to run an additional 15 min before the fluorine and the mercury arcs ate shut off. The preaerosol furnace, the evaporator heater unit, and the coolant pump are shut off. Once the system approaches ambient conditions, all the helium carriers are shut off and the product trap valves are closed The product trap and its Dewar flask filled with liquid nitrogen are removed to the vacuum line where the trap is evacuated... 

Figure 2.12 Schematic representation of an on-line SPE-GC system consisting of three switching valves (VI-V3), two pumps (a solvent-delivery unit (SDU) pump and a syringe pump) and a GC system equipped with a solvent-vapour exit (SVE), an MS instrument detector, a retention gap, a retaining precolumn and an analytical column. Reprinted from Journal of Chromatography, AIIS, A. J. H. Eouter et al, Analysis of microcontaminants in aqueous samples hy fully automated on-line solid-phase extraction-gas chromatography-mass selective detection , pp. 67-83, copyright 1996, with permission from Elsevier Science.

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.

Figure 6.3 Schematic diagram of an on-line SFE-GC instmment 1, carbon dioxide 2, high-pressure syringe pump 3, tliree-poit valve 4, extraaion cell 5, oven 6, gas cliromato-graph.

Figure 6.9 Schematic diagram of an on-line SFE-CEST system (from ref. 58) 1, CO2 cylinder 2, syringe pump 3, oven 4, exuaction cell 5, interface 6, CE insti ument.

Heber-pumpe, /. siphon pump, -rohr, n. siphon tube or pipe, siphon. -sauremesser, m. syringe hydrometer for acids, -scbreiber, m. siphon recorder. 

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... 

Busfield and coworkers extended the technique to the study of less reactive carbon-centered radicals (e.g. cyanoisopropyl)353354 and short propagating radicals505 507. The very low concentration of nitroxide required to allow limited propagation was maintained by feeding with a syringe pump. 

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