Agilent Technologies 7100 User Manual page 119

Using the Agilent 7100 Capillary Electrophoresis System 5
Capillary Electrophoresis, CE
Outlet Vials
Outlet vials (for example, waste vials) should also be filled with enough liquid
to touch the capillaries. Thus, the liquid flow through the capillary does not
produce droplets at the capillary end, which can cause pressure. This would
influence the injection amount. If the waste vial is filled with liquid, outgoing
droplets cannot be drawn up the electrode by capillary effects but are flushed
completely out of the outlet electrode. Therefore, they cannot contaminate the
lift head or the next outlet vial. Outlet vials that are used during analysis (for
example, for fraction collection) need to be filled to a higher level (1 cm). The
liquid must touch the electrode to enable a current to flow.
Vial in Position 49 (Replenishment Lift)
Using replenishment, it is good practice to have a capped vial filled with buffer
or water in position 49 (= home position of the replenishment lift). The
replenishment needle stays in the liquid and is prevented from buffer
precipitation and the resulting blockage of the needle. Water in vial 49 can
change the buffer composition inside the replenishment needle and the
adjacent tubing over time due to diffusion. This effect might influence the
reproducibility of analysis. Therefore, we recommend using buffer.
Inserting the Vials
The tray of the Agilent CE instrument is used for both buffer and samples. The
CE diagram of the Agilent ChemStation controls the tray.
1 From the CE diagram open the control menu by clicking the tray icon.
2 The dialogue Get Vial... allows you to enter the vial number or tray position.
3 Wait until the tray has stopped moving.
4 Open the tray door.
5 Access the vial which is in the front.
The number is engraved in the sample tray.
For safety reasons, the tray can only be moved by the Agilent ChemStation when the tray
N O T E
door is closed.
6 Click Done after you have accessed all the vial positions you need.
Agilent 7100 Capillary Electrophoresis System User Manual 119