A new gradient pump device, capable to generate accurate nano- and micro-flow rate gradients from a conventional HPLC system is provided. The new device includes an electric actuated, computer controlled, 14-port multiposition HPLC valve. Six reservoirs are connected to the valve, and each one is filled with a specific mixture of solvents, forming a mobile phase of a desired increasing strength. Loop loading is carried out at high flow rate in order to speed up the procedure. The low flow rate can be produced from the conventional HPLC is produced using a splitting device. A syringe pump can also be used for the generation of the flow rate. In this case the mobile phase stream is pushed by a damp-free plunger at a nano-scale flow rate, and a spitting device is not necessary. Through the electric actuator it is possible to select the reservoir to be on-line with the column for a given time, thus generating a solvent gradient, through a sequence of controlled segments of precise mobile phase composition. In this way it is possible to draw a specific gradient of a given shape (i.e., linear, convex, concave) for different separation needs. The gradient realized has a typical profile which can be smoothed out by a mixing chamber of a selected volume positioned before the injector.
DEVICE FOR GENERATING MICRO- AND NANO-FLOW MOBILE PHASE GRADIENTS FOR HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY
CAPPIELLO, ACHILLE
2007
Abstract
A new gradient pump device, capable to generate accurate nano- and micro-flow rate gradients from a conventional HPLC system is provided. The new device includes an electric actuated, computer controlled, 14-port multiposition HPLC valve. Six reservoirs are connected to the valve, and each one is filled with a specific mixture of solvents, forming a mobile phase of a desired increasing strength. Loop loading is carried out at high flow rate in order to speed up the procedure. The low flow rate can be produced from the conventional HPLC is produced using a splitting device. A syringe pump can also be used for the generation of the flow rate. In this case the mobile phase stream is pushed by a damp-free plunger at a nano-scale flow rate, and a spitting device is not necessary. Through the electric actuator it is possible to select the reservoir to be on-line with the column for a given time, thus generating a solvent gradient, through a sequence of controlled segments of precise mobile phase composition. In this way it is possible to draw a specific gradient of a given shape (i.e., linear, convex, concave) for different separation needs. The gradient realized has a typical profile which can be smoothed out by a mixing chamber of a selected volume positioned before the injector.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
