High performance liquid pumping systems

The basic components of a high-performance liquid chromatographic system are shown in Figure 3.1. The instrument consists of (a) eluent containers for the mobile phase, (b) a pump to move the eluent and sample through the system, (c) an injection device to allow sample introduction, (d) a column(s) to provide solute separation, (e) a detector to visualize the separated components, (f) a waste container for the used solvent, and finally (g) a data collection device to assist in interpretation and storage of results. 

High Performance Liquid Chromatographic (HPLC) Analysis. A Waters HPLC system (two Waters 501 pumps, automated gradient controller, 712 WISP, and 745 Data module) with a Shimadzu RF-535 fluorescence detector or a Waters 484 UV detector, and a 0.5 pm filter and a Rainin 30 x 4.6 mm Spheri-5 RP-18 guard column followed by a Waters 30 x 3.9 cm (10 pm particle size) p-Bondapak C18 column was used. The mobile phase consisted of a 45% aqueous solution (composed of 0.25% triethylamine, 0.9% phosphoric acid, and 0.01% sodium octyl sulfate) and 55% methanol for prazosin analysis or 40% aqueous solution and 60% methanol for naltrexone. The flow rate was 1.0 mL/min. Prazosin was measured by a fluorescence detector at 384 nm after excitation at 340 nm (8) and in vitro release samples of naltrexone were analyzed by UV detection at 254 nm. 

Figure 7.5 Schematic diagram of a high performance liquid chromatography (HPLC) system. The solvent(s) are pumped through the system, and the sample injected just before the column where separation occurs. Detection is often by UV/visible spectrophotometry at a fixed wavelength.

The isocratic system (Fig. 1.2 (a)) provides an economic first step into high-performance liquid chromatography techniques. The system is built around a high-performance, dual-piston, pulse-free pump providing precision flow from 0.01 to 5ml min-1. 

High Performance Liquid Chromatography (HPLC) (Chapter 30) gives an elaborate discussion of theoretical aspects. Instrumentation encompasses the various important components e.g., solvent reservoir and degassing system pressure, flow and temperature pumps and sample injection system ... 

First, the low boiling point (37 C) can lead to handling difficulty. We found it necessary to replace the Waters 6000A pump in the Waters Model 244 high performance liquid chromatograph (HPLC) with a Waters M45 pump to avoid an occasional interruption in flow which we assured to be caused by vapor lock. Second, there are health hazards associated with the use of HFIP, and hygenlc laboratory procedures should be followed. The system should not be used prior to consulting the HFIP Product Information and Material Safety Data Sheet from Du Pont. 

High-performance liquid chromatography (HPLC) is one of the premier analytical techniques widely used in analytical laboratories. Numerous analytical HPLC analyses have been developed for pharmaceutical, chemical, food, cosmetic, and environmental applications. The popularity of HPLC analysis can be attributed to its powerful combination of separation and quantitation capabilities. HPLC instrumentation has reached a state of maturity. The majority of vendors can provide very sophisticated and highly automated systems to meet users needs. To provide a high level of assurance that the data generated from the HPLC analysis are reliable, the performance of the HPLC system should be monitored at regular intervals. In this chapter some of the key performance attributes for a typical HPLC system (consisting of a quaternary pump, an autoinjector, a UV-Vis detector, and a temperature-controlled column compartment) are discussed [1-8]. 

Fig. 6.1.4 Components of the high-performance liquid chromatography (HPLC) system for oxidized pterins with column switching. The autosampler starts the chromatography software, which controls valves and pumps. Pump 3 is used only for rinsing the precolumn. Details of the three valves and their different positions are explained in Fig. 6.1.5...

J,m poly(tetrafluoroethylene) (PTFE) syringe-tip filters High-performance liquid chromatography (HPLC) system equipped with Quaternary pump Diode array detector Vacuum degasser... 

Williams et al. used a high performance liquid chromatographic assay method for dipyridamole monitoring in plasma [71]. The HPLC system uses a Waters model 6000 A solvent delivery pump equipped with a U6K injector, a pBondapak C 9 column (30 cm x 39 mm 10 pm), and a Model 440 absorbance detector. The signal from the detector was quantified using a Shimadzu data processor and an Omni-Scribe recorder. A mobile phase flow rate of 1.5 mL/min was produced by a pressure of approximately 102 atm (1500 p.s.i.). The mobile phase was 50 50 mixture of acetonitrile and 0.01 M sodium phosphate in water (adjusted to pH 7). The absorbance reading of dipyridamole in methanol was made at 280 nm. 

Chromatography. Filtered polysaccharide solutions were analyzed using an SEC system consisting of an automatic sampler (Waters WISP, Waters, Milford, MA) with a high-performance liquid chromatography pump (Waters model 590), pulse dampener (Viscotek, Houston, TX), viscometer... 

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