Hanna Instruments HI 903 - Manual (Page 169)

Method ID: HI8011EN
5.0 mg/mL Titrant Standardization using Disodium Tartrate Dihydrate
for one-component titrant
Titrator Application Methods: General Methods - r. 0.4
Description:
Method for the standardization of 5.0 mg/mL One-
Component Karl Fischer Titrant using Disodium
Tartrate Dihydrate water standard. The results are
expressed in mg/mL.
Electrode:

HI 76320 Double Platinum Pin Electrode
Reagents:

5 mg/mL One-Component KF Volumetric Titrant

Disodium Tartrate Dihydrate, 15.66% H
2
O (w/w)

Dry Methanol

Dry Formamide
Other Accessories:

A clean, dry weigh boat

GL 45-Thread Solvent Bottle
Procedure:

Setup titrator according to the instruction manual.
 Press “Select Method” from the main screen. Use
the arrow keys to highlight ‘HI8011EN Stdz
5mg/mL w/ Tartrate
’ and press “Select”.

Install a 5-mL burette filled with 5 mg/mL One-
Component KF Titrant to be standardized and
verify that no air bubbles are present in the burette
or tubing. If necessary prime until all air has been
removed completely.

Connect the solvent bottle top assembly to the
bottle of methanol according to the manual.

Prepare at least 200 mL of solvent by mixing 2
parts dry methanol and 2 parts dry formamide in a
solvent bottle.

Attach the solvent bottle top assembly to the bottle
according to the instruction manual.

Prepare the titration vessel according to the
manual. Dispense enough solvent from the solvent
bottle to fill the vessel to the “min” line (about 50
mL).
 Press “Start/Stop” to pre-titrate the solvent and the
titration vessel moisture. Allow the background
drift rate to stabilize before proceeding to the next
step.

Add 0.050 g to 0.100 g of tartrate standard to a
weigh boat.

Weigh the weigh boat and tartrate standard.
 Press “Start Analysis”. You will be prompted to
enter the sample size.

Quickly remove the sample port plug from the
beaker assembly, pour the tartrate into the titration
vessel, and replace the sample port plug. Pay
attention not to get any sample on the electrode or
beaker walls. If necessary swirl the titration vessel
by hand.

Weigh the weigh boat again in order to determine
the added standard 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 “Standardization
Result
” screen is displayed. The results are
expressed in mg/mL.
Method Parameters:
Name: Stdz 5mg/mL w/ Tartrate
Method Revision: 1.0
Type: Titrant Standardization
Predispensing Amount: 15 %
Pre-Analysis Stir Time: 30 Sec
Stirring Speed: 900 RPM
Stirbar Type: Medium
Drift Entry: Automatic
Solvent: MeOH Form. 2:1
Standard: Sodium Tartrate
Type: Solid by mass
Concentration Unit: %
Water Content: 15.66 %
Standard Size: 0.1000 g
Titrant: Composite 5
Titrant Type: One Component
Nominal Titrant Conc.: 5.0000 mg/mL
Std. Titrant Conc.: 5.0000 mg/mL
Date/Time: Jan 1, 2011 12:00
Titrant Age Reminder: 2d:00h:00m
Control Parameters:
Start Mode: Normal
Standby Mode: Enabled
Standby Duration: 720 minutes
Imposed Current: 20 uA
Minimum Dose: 2.000 uL
Maximum Dose: 40.000 uL
Timed Increment: 1 second
End Point Value: 180.0 mV
Signal Averaging: 3 Readings
Flow Rate: 10.0 mL/min
Termination Parameters:
Maximum Duration: 1200 sec
Maximum Titrant Volume: 10.0000 mL
Term. Criterion: Relative Drift
Relative Drift: 7.0 ug/min
Calculations:
Titrant units: mg/mL
Titrant volume consumed: V (mL)
Final Results Units: mg/mL
Standard Concentration: 15.66 %
Standard mass: 0.1000 g