Hanna Instruments HI 904 - Manual (Page 143)

Method ID: HI9001EN
Titrator Validation with 1.0 mg/g Water Standard
Titrator Application Methods: General Applications – r. 1.0
Description:
Method for validation of titrator accuracy. The
results are expressed in mg/g and shouldmatch the
certified value (within the uncertainty limits) provided
by the manufacturer of the standard.
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
 1.0 mg/g Liquid Water Standard, Certified
Other Accessories:
 A clean, dry 3-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 ‘HI9001EN Validation-
1.0mg/g Std’ 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.
 Open an ampoule of water standard.
 Rinse the syringe and needle by in taking a small
amount of standard and expelling it into a waste
container.
 Fill the syringe and needle with the standard. Any
unused standard remaining in the ampoule should
not be used later in order to avoid contamination
from atmospheric water.
 Weigh the syringe, needle and standard.
 Press “Start Analysis”. You will be prompted to
enter the sample size.
 Dispense 0.7500 g to 1.0000 g of
standard(approximately 1 mL) into the titration
vessel through the septum using the needle. Pay
attention not to get any standard on the electrode
or beaker walls. If necessary, swirl the titration
vessel by hand.
 Clear the needle of residual standard by in taking
a very small volume of air from the titration vessel.
If a “hanging drop” of standard 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 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 “Sample Analysis
Result” screen is displayed. The results are
expressed in mg/g of water.
 Perform two more titrations with the remaining
water standard in the syringe.
Method Parameters:
Name: Validation- 1.0mg/g Std
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: DefaultSample
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: 20.000 mg
Term. Criterion: Relative Drift
Relative Drift: 5.0 μg/min
Result Unit: mg/g
Calculations:
Water titrated: H
2
O (μg)
Final results units: mg/g
Sample mass: 1.0000 g
mg/g =
water (μg )
1.0000 g ×
1 mg
1000 μg
Results:
Titration Report
Method Name: Moisture in Solvent
Time & Date: 12:00 Jan 01, 2013
Sample Size: 0.9412 g
Drift Value: 0.8ug/min
Titrated Water: 950.02ug
Result: 1.0078mg/g
Titration Duration: 1:53 [mm:ss]
Generator Electrode Type: HI 900518
Titration went to Completion
Operator Name:
Analyst Signature: _______________________