Gradient elution accessory

The Tracor Chromatec Model 8000 gradient elution accessory uses two solenoid-... 

Gradients generated with pneumatic pumps. The DuPont gradient elution accessory and the Jobling Model JL 921 gradient generator are similar and use... 

Fig. 7. DuPont gradient elution accessory, a, b = proportioning valves, c = holding coil, d, e, T, g, k = valves, h = solvent reservoirs, 1 = source of gas under constant pressure 25 psi), j - vacuum, 1 = pump, m = drain, n = mixing chamber, p = chrofnatograph (injection port, column, detector(s)), q = measuring container.

DuPont system when the Model 833 precision flow controller is coupled with the gradient elution accessory immediately after the pneumatic pump on solvent A line (Fig. 7). The air pressure is adjusted so that the flow-rate is kept constant. Also in the DuPont device, solvents that differ widely in viscosity can be difficult to mix and the shape of the gradient can be altered. 

On the DuPont Model 830 gradient elution accessory, Micromeritics Model 7OD0 gradient system, Perkin-Elmer Model 601 gradient system, Spectra-Physics Chromatronix Model 744 solvent programmer, Waters Model 660 sol vent prograimer,... 

In the DuPont 838 programmable gradient elution accessory, the gradient curve is drawn on a metallized paper sheet which is set on a rotating cylinder that rotates at a frequency of 1 cycle every 7.5 sec. A sensing cell moves along the... 

Fig.6. Schematic of the solvent gradient elution CEC apparatus with ramping voltage accessory. (Reprinted with permission from [204] Copyright 1996 American Chemical Society)...

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