Modules

Eliminating pulsation

The problems caused by pressure variations in solvent delivery when switching between the two pump heads has been improved with a new design that precisely controls the plunger drive. The LC- 4 0 0 0 series analytical pumps offer flow rate precision with RSDs of better than 0.05% (difficult to achieve with commercially available pumps). The PU-4180 and 4185 pumps operate at pressures up to 70 MPa, designed mainly for use with RHPLC for core- shell columns or similar micro packing materials as well as working at pressures commonly used for conventional HPLC. The PU- 4280 and PU- 4285 UHPLC pumps provide precise flow at pressures up to 130 MPa; for columns with particle sizes of less than 2 μm. The LC-4000 series UHPLC system can also be used for rapid analysis HPLC (RHPLC) and conventional HPLC.

Pump Configurations

The PU-4180/85 and PU-4280/85 analytical pumps can be configured for both single pump gradient and multiple pump gradient operation. The single pump quaternary gradient module offers excellent gradient formation for up to four solvents. The newly designed 4-way solvent valve for switching the four solvents is synchronized to the operation of the pump motor control – variable cycle adaption optimizes delivery according to gradient resolution and flow rate. This highly efficient quaternary gradient mode can be applied to a wide flow-rate range from low to high flow rates. Two and three pump binary or ternary gradient modules with optional built-in degasser are available for fast cycle high-resolution gradient formation; the response time is superior to the single pump quaternary gradient system.

Solvent Degassing

The in-line vacuum degasser module uses a new Teflon AF membrane with a hold-up volume of only 400μL (per solvent line); this offers very quick solvent replacement with minimal waste. Despite its small size, the new degasser offers more effective and stable degassing than larger previous generation models. A degasser for preparative-HPLC is also available.

The LC-4000 Preparative-HPLC System includes pumps at three scales. The PU-4086 pump offers flow rates up to 20 mL/min, the PU-4087 pump up to 50 mL/min and the PU-4088 up to 120mL/ min. Both single and multi-pump gradient modes can be used with the PU-4086 pump platform whilst the PU-4087 and PU-4088 are used in multi-pump mode only. The new MK2 technology used in the PU-4086 and PU-4087 motor driver control has been increased so that the maximum pressure can be used at higher flow-rates for all pump models. Solvents can be delivered at higher flow rates and higher pressures for use with longer preparative HPLC columns that generate more back pressure and for faster and more productive preparative separations. Dynamic mixers, solvent selection valves and the prep degasser can be installed in the expansion bays in both the PU-4086 and PU-4087 modules.