Hanna Instruments HI934 Bedienungsanleitung Seite 110

3
DESCRIPTION
Method for the determination of moisture in extraction /
dissolution solvent. Solvents should be less than 1.00
mg/g, substances with very low water content may
require solvents with less than 0.100 mg/g. Results are
expressed in ppm.
ELECTRODE
• HI76330 Dual Platinum Pin Electrode
• HI900517 Generator with Diaphragm
-or-
• HI900512 Generator without Diaphragm
REAGENTS
• General Purpose Coulometric Karl Fischer Reagent
ACCESSORIES
• 1 mL syringe (clean and dry)
• 22-gauge, 6" non-coring septum penetration needle
(clean and dry)
• Solvent bottle, GL45 thread
DEVICE PREPARATION
• Connect the reagent bottle top assembly to the bottle
of reagent according to the manual.
• Assemble the titration vessel according to the
instruction manual.
• Press
keys to highlight HI9301EN Moisture in Solvent and
press
• Dispense enough methanol from the reagent bottle
to fill the vessel to the "min" line (about 75 mL).
• Press
titration vessel moisture. Allow the background drift
rate to stabilize before proceeding to the next step.
3-4
HI9301EN MOISTURE DETERMINATION IN SOLVENT
for external dissolution or extraction
from the main screen. Use the arrow
.
key to pre-titrate the solvent and the
ANALYSIS
• Prepare an extraction / dissolution vessel with
solvent and stir (see an applicable method for proper
solvent amount and stirring time).
• Stop stirring the solvent in the extraction / dissolution
bottle.
• Fill the syringe and needle with the extraction /
dissolution solvent.
• Weigh the syringe, needle and solvent.
. You will be prompted to enter the
• Press
sample size.
• Dispense 1.00 g of solvent into the titration vessel
through the septum using the needle.
• Pay attention not to get any sample on the electrode
or beaker walls. If necessary swirl the titration vessel
by hand to remove any solvent from the electrode or
beaker wall.
• Clear the needle of residual sample by in taking
a small volume of air from the titration vessel. If
a "hanging drop" of solvent is seen on the end of
the needle, dip the end of the needle briefly in the
solvent.
• Remove the needle from the titration vessel and
weigh the syringe again in order to determine
the added sample mass (by difference of the two
measurements.)
• Use the numeric keypad to enter the exact weight
and press key to start the analysis.
• At the end of the titration, the Sample Analysis
Result screen is displayed. The results are expressed
in ppm of water.