Solvent delivery systems flow reproducibility

The solvent delivery system is one of the most important components of the liquid chromatograph since its performance directly affects retention time reproducibility d detector baseline stability [1,2,39,40]. As well as the pump, other components such as check valves, flow controllers, mixing... 

The function of the solvent delivery system is to deliver the mobile phase (eluent) through the chromatograph, accurately and reproducibly. The solvent delivery system comprises the pump, check valves, flow control-... 

Solvent Delivery System. Solvent delivery systems provide the flow rate of the carrier liquid through the whole separation system. Highly stable liquid flow rates free of pulsations, a broad range of adjustable flow rates, repeatability, and reproducibility of the adjusted flow rate are their most important parameters. A broad range of adjustable flow rates is important. The pumps must be corrosion resistant and inert to the solvents used. The channels for FFF have very low hydrodynamic resistance and, consequently, the solvent delivery systems should not rely on high pressure operation. Furthermore, it is very important that the flow rate is free of pulsation. The stability of the flow rate and, consequently, of the velocity profile inside the separation channel is the most important requirement for the validity of all the theoretical relationships for retention and dispersion and thus for the choice of the solvent delivery system. 

Fig. 7.2. Flow diagram of standard laboratory instrumentation used for chromatography with electrochemical or spectrophotometric detection of metal dithiocarbamate complexes. 1 = chromatographic solvent, 2 = solvent delivery system, 3 = it jec-tion system, 4 = guard column, 5 = separator column, 6 = suppressor column, 7 = spectrophotometric detector, 8 = electrochemical detector, 9 = readout device, 10 = microprocessor. Reproduced by courtesy. J. Liquid Chromatog. 6 (1983) 1799.

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