The use of syringe-type pumps in liquid chromatography in order to achieve a constant flow-rate

摘要: Abstract The variation of the flow-rate mobile phase pumped through a chromatographic column by screw-driven syringe-type pump is discussed. It shown that because compressibility liquids, steady-state flow achieved only after long period, which depends on characteristics pump, resistance and nature liquid. This period normally between 15 60 min if liquid pumping starts from zero pressure at constant piston speed. retention times observed for compounds injected during transitory can be up to several greater than those same under conditions. All data efficiencies measured are not reproducible meaningless. Quantitative results also reproducible. Instructions given better use this type which, in spite some well-known advantages, has been found very difficult any measurements.