Metrohm 787 KF Titrino - Manual (Page 33)

2.6 Parameters, key <PARAM>
787 KF Titrino
29
Solid samples
Use the glass weighing spoon 6.2412.000 and dispose the sample through the opening
for the septum stopper.
Liquid samples
Use a disposable syringe (2...20 mL) or a micro-syringe with a long needle attached.
Puncture the septum and dispose the sample carefully. When using disposable syringes,
add the liquid sample carefully without dipping into the solvent. Draw back the last drop
of sample into the syringe before you redraw the needle. For disposing an exact, small
volume of liquid sample, use a micro-syringe. Proceed as described above, but dip the
needle into the preconditioned solvent and dispose the sample carefully. Here drawing
back of solvent or sample adhering to the needle is not recommended.
Always keep in mind to exchange the septum as soon as it shows any large punctures
impairing the tightness of the titration cell.
Pasty, viscous samples
For samples which cannot be disposed with a needle because of their high viscosity, you
can handle your samples with disposable syringes with a large volume without using a
needle. Dispose your sample through the opening of the septum stopper. Back-weigh the
syringe after addition of the sample. Be sure to wipe off any adhering excess sample
substance of the syringe before taring it.
In any case, pay attention to prevent the penetration of atmospheric moisture into the
titration vessel when you are disposing the sample. If you still have to open the titration
cell for any reason, determine a blank value and take it into account for the calculation of
the titration result (see page 34).