Dismantling the Gradient Mixer

The reservoir cylinders (7), control valve (12) and flow control valve (18) may be removed from the base plate by unscrewing them. To remove the stirrer blade (6) from the motor unit (1, 2), unscrew the nylon screw (5) a few turns. It is not necessary to remove the screw completely. The lid of the motor unit should not be removed.

6. Operation

Operating the Gradient Mixer

1.Close the control valve (12) and flow control valve (18) and pour the required amount of starting solution into the mixing reservoir. The graduations may be used as an approximate guide to the volume of liquid in the reservoirs.

2.Mount the motor unit (1, 2), with the stirrer blade (6), on the mixing reservoir.

3.Open the control valve (12) slightly so that the channel between the reservoirs fills with solution and a small amount of liquid emerges into the other reservoir. Close the control valve.

4.Pour the gradient-forming solution into the empty reservoir until the liquid levels in the two reservoirs are nearly the same. The level in the mixing reservoir should be slightly higher than the level in the other reservoir to avoid a step at the beginning of the elution.

5.Open the control valve (12) fully, one complete revolution, start the motor and begin the elution by opening the flow control valve (18). If a pump is used to control the eluent flow, the flow control valve (18) should be fully open, one complete revolution .

The Gradient Mixer will give linear ionic strength gradients and reproducible, but non-linear, pH gradients. The exact shape of the pH gradient obtained will depend on the buffer salts used and the ionic strengths and pH’s of the buffer solutions. The use of gradient elution in ion exchange chromatography is described in the booklet “Ion Exchange Chromatography – principles and methods.”

7. Maintenance

Warning!

When using hazardous chemicals, all suitable protective measures such as protective glasses, must be taken.

Cleaning

Ordinary laboratory detergents may be used to clean the gradient mixer. Enzyme detergents are recommended for removing protein aceous contaminants. The mixer, including

the stirrer blade but not the motor unit, may be autoclaved at 121 °C for 20 min.

Caution!

Do not autoclave the motor unit or drain the motor in strong detergents.

8. Technical specification

Mixing chamber

300 ml

volume

 

Environment

+4–40 °C

 

20–95% relative humidity

Material of

Polymethylpentene,

wetter parts

Polypropylene, glass fibre reinforced

 

polypropylene and fluororubber.

Chemical resistans

The wetted parts are resistant to

 

aqueous and organic solvents

 

commonly used in ion change

 

chromatography and solutions

 

containing inorganic and organic

 

acids, alkalis and alcohols.

Power requirements

100–120 VAC or 220–240 VAC,

 

50–60 Hz

Power consumption

7 VA

Safety standards

This products meets the requirements

 

of the Low Voltage Directive (LVD)

 

73/23/EEC through the harmonized

 

standards EN61010-1 and EN60742.

Note: The declaration of conformity is valid for the instrument when it is:

•used in laboratory locations,

•used in the same state as it was delivered from GE Healthcare Bio-Sciences AB

except for alterations described in the user manual,

•used as a “stand alone” unit or connected to other CE labelled GE Healthcare Bio-Sciences AB instruments or other products as recommended.

i56-2853-00 AE, 2002-12 • p2