Loading The Auto-Pipette - MicroCal VP-ITC User Manual

VP-ITC MicroCalorimeter User's Manual
•
Remove all air from the filling syringe, or tap the syringe glass so that all air is at the top
volume of the syringe. Do not allow air to be put into the cells.
•
After removing the bubbles, insert the syringe into the cell and gently touch
the bottom of the cell with the tip of the syringe needle. Raise the needle
tip about 1 mm off the bottom of the cell. The syringe will remain at this
location for the duration of the filling procedure. Do not raise the syringe
during the filling process.
•
Slowly inject solution into the cell until you see it spill out the top of the
cell stem. Finish the filling with an abrupt spurt of ca. 0.25 ml of solution
into the cell. If possible, repeat the 0.25 ml abrupt spurt of solution one or
two times. This bursting of .25 ml of solution will help remove bubbles t
may rest on the edges of the coin shaped area where the junction of the stem is.
•
The final step is to drain off the solution overflow. Do this by gentl
syringe into the cell port (just below the visible portion of the cell
port) and find the ledge that is formed where the cell stem m
the cell port. Place the syringe on the ledge at the top of the metal
cell stem and remove the excess solution.
•
Fill the reference c
excess water. To prevent sample overflow into the reference
cap the reference cell with the Reference Plug. Please Note:
There is no need to refill the ITC reference with each experiment. If the water
was thoroughly degassed before filling, it may be good for a week or two with
no attention.
A Word of Caution
If the reservoir should overflow during the filling procedure, the fluid may contaminate the stir
motor bearing and damage it beyond repair. Care should be taken not to over flow the reservoir.
If an overflow does occur, the injector should be removed and the bearings on the underside
should be wiped dry.
personnel for further recommendations.
Please refer to the diagram below.
•
Degas the titrant for ca. 5 minutes and place in the pipette filling tube.
•
The pipette filling tube should be placed into the bottom of the stand.
•
Carefully, insert the auto-pipette into the pipette stand.
!
Caution: Be careful not to hit the long needle of the injection syringe against any object, as
this could cause the needle to bend and expel some solution from the syringe and result in a
poor first injection for the experiment. If the long needle is bent far enough it may cause a
permanent deformation in the needle making the syringe unusable for future experiments.
ell with water, as above, then remove any
If internal contamination is expected you should consult with MicroCal

3.4 Loading the Auto-Pipette

eets
cell,
42
hat
y inserting the tip of the
Sample reservoir