Hanna Instruments HI 904 - Manual (Page 145)

Method ID: HI9301EN
Moisture Determination in Solvent
for external dissolution or extraction
Titrator Application Methods: General Applications – r. 1.0
Description:
Method for the determination of moisture in
extraction/dissolution solvent. The results are
expressed in mg/g and should be less than 1.00
mg/g. Extractions/dissolutions of substances with
low water contents may require very dry solvents
(<0.100 mg/g).
Electrode:
 HI 76330 Double Platinum Pin Electrode
 HI 900517 Generator with Diaphragm
-or-
 HI 900518 Generator without Diaphragm
Reagents:
 General Purpose Coulometric Karl Fischer
Reagent
Other Accessories:
 A clean, dry 1-mL syringe
 A clean, dry 22-gauge, 6” non-coring septum
penetration needle
 GL 45-Thread Reagent Bottle
Procedure:
 Setup titrator according to the instruction manual.
 Press “Select Method” from the main screen. Use
the arrow keys to highlight ‘HI9301EN Moisture in
Solvent’ and press “Select”.
 Connect the reagent bottle top assembly to the
bottle of reagent according to the manual.
 Prepare the titration vessel according to the
manual. Dispense enough reagent from the
reagent bottle to fill the vessel to the “min” line
(about 100 mL).
 Press “Start/Stop” to pre-titrate the reagent and
the titration vessel moisture. Allow the
background drift rate to stabilize before running a
titration.
 Prepare an extraction/dissolution vessel with
solvent and stir (see an applicable standard
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.
 Press “Start Analysis”. You will be prompted to
enter the sample size.
 Dispense 0.8000 g to 1.0000 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.
 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 “Enter” to start the analysis.
 At the end of the titration the “Sample Analysis
Result” screen is displayed. The results are
expressed in mg/g of water.
Method Parameters:
Name: Moisture in Solvent
Method Revision: 1.0
Type: KF Coulometric
Pre-Analysis Stir Time: 5 Sec
Stirring Speed: 900 RPM
Stirbar Type: Medium
Drift Entry: Automatic
Reagent: General Purpose
Sample Parameters:
Sample Determ.: Normal
Sample Name: Solvent
Sample Type: Mass
Sample Size: 1.0000 g
Control Parameters:
Titration Speed: Auto
Standby Mode: Enabled
Standby Duration: 12:00 [hh:mm]
Imposed Current: 2uA
End Point Value: 100.0 mV
Generator Current Mode: Auto
Signal Averaging: 2 Readings
Termination Parameters:
Maximum Duration: 1200 sec
Maximum Titrated Water: 10.000 mg
Term. Criterion: Relative Drift
Relative Drift: 3.0 μg/min
Result Unit: ppm
Calculations:
Water titrated: H
2
O (μg)
Final results units: ppm
Sample mass: 1.0000 g
ppm =
water (μg )
1.0000 g
Results:
Titration Report
Method Name: Moisture in Solvent
Time & Date: 12:00 Jan 01, 2013
Sample Size: 1.0322 g
Drift Value: 0.9ug/min
Titrated Water: 208.10 ug
Result: 200.1ppm
Titration Duration: 1:45 [mm:ss]
Generator Electrode Type: HI 900518
Titration went to Completion
Operator Name:
Analyst Signature: _______________________