Chromatography pumps

Surveyor liquid chromatography pump (Thermo Finnigan). 

HPLC analysis. The HPLC system consisted of a Waters 590 chromatography pump, a Waters R401 differential refractometer and a Perkin Elmer ISS-100 autosampler. A Biorad HPX87H column (strong ion exchange resin in H+ form) was used with 3 10 3 M trifluoro acetic acid as mobile phase at 60 °C. 

The second alternative is to direct specific samples to the NMR that are of particular interest. The sample can then be trapped in the cell and data acquired from an adequate number of pulses to provide the required resolution. Subsequently, the sample can be expelled from the cell using solvent supplied directly from the chromatography pump. The third alternative is to direct the eluent from the column to a sample loop where it can be stored until the spectrometer is available to take data. If necessary, a number of solutes can be stored in different loops and they can be examined when convenient. When the data has been acquired from one sample, the solute stored in the next loop can then be displaced into the NMR cell. Samples that have been examined can either be displaced to waste or collected for further examination. A photograph of the Varian flow control device for the LC/NMR system is shown in figure 41. 

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... 

Caprioli and Lin first described this method for the characterization of penicillin G in 1990 [19]. A diagram of the microdialysis/cfFAB experimental setup used is shown in Fig. 8. Dialysate was allowed to collect in a 20- dL sampling loop via syringe pump. After collection, the injection valve was switched and a high-performance liquid chromatography pump was used to deliver the microdialysis sample to the mass spectrometer. Mass spectra of penicillin from both a standard and an in vivo microdialysis sample (shown in Fig. 9) compare well. 

Liquid chromatography pumps can deliver a range of flowrates from nL/min to 10 mL/min depending on the type of pump purchased, e.g. standard or microflow. A standard pump used at a flowrate of 1 mL/min with a standard column of 250X4.6mm dimensions and... 

Retention gap techniques with on-column interfaces are used to analyze those analytes that are poorly retained during full concurrent eluent evaporation [98-102,105]. The eluent fraction is pushed by the liquid chromatography pump into the thermostatted retention gap where it is mixed with carrier gas and evaporated at a temperature below the pressure corrected eluent boiling point. A layer of condensed solvent (flooded zone) is formed in front of the evaporation site that acts as a temporary retaining liquid phase. Partial concurrent eluent evaporation during transfer allows the use of shorter retention gaps and an increase in the eluent volume that can be transferred. A 10 m x 0.53 mm... 

For tests using a Rheometrics pressure rheometer (RPR), the HPG solution is pumped with a chromatography pump, and the cross-linker is injected into the flowing polymer solution with a syringe pump. The two... 

M600 Chromatography Pump and U6R Injector (Waters Assoc.)... 

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