Hanna Instruments HI 4111 User manual

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HI 4011HI 4011
HI 4011HI 4011
HI 4011
HI 4111HI 4111
HI 4111HI 4111
HI 4111
Iodide Ion
Selective Electrode
Instruction Manual
Half-cell
Combination
IODIDE
HI 4011
HI 4111
IODIDE
COMBINATION

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HI 4011 Iodide Half-cellHI 4011 Iodide Half-cell
HI 4011 Iodide Half-cellHI 4011 Iodide Half-cell
HI 4011 Iodide Half-cell
HI 4111 Iodide Combination ElectrodeHI 4111 Iodide Combination Electrode
HI 4111 Iodide Combination ElectrodeHI 4111 Iodide Combination Electrode
HI 4111 Iodide Combination Electrode
I.I.
I.I.
I. Introduction:Introduction:
Introduction:Introduction:
Introduction:
The Hanna HI 4011 and HI 4111 are ion selective elec-
trodes designed for the measurement of Iodide ions in
aqueous solutions. The HI 4011 is a solid state half-cell
sensor that requires a separate reference. The HI 4111 is a
combination ion selective electrode.
IIII
IIII
II. SpecificationsSpecifications
SpecificationsSpecifications
Specifications
Type: Solid State electrode with
a Silver Iodide pellet.
Ion(s) measured: Iodide (I--
--
- )
Measurement range: 1.0 M to 1 X 10-7M
127,000 to 0.01 ppm
Interfering ions: Cyanide and Mercury
must be absent. Strong
reducing solutions will
destroy membrane. Ratio
of interfering ion to I--
--
-must
be less than the ratio
indicated below:
` 500 for Br--
--
-Bromide
500 for Cl--
--
-Chloride
Operating Temperature: 0-80°C
Operating pH: 2.0-13.0 pH
Dimensions: 12 mm (OD) X 120 mm
nominal insertion
(0.47” X 4.72”)
Connection: BNC

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III.III.
III.III.
III. Theory of OperationTheory of Operation
Theory of OperationTheory of Operation
Theory of Operation:::::
The HI 4011 or HI 4111 Iodide electrodes are potentiomet-
ric devices used for the rapid determination of free Iodide
ions in food products, plants, and as an indicator in titra-
tions. The electrode functions as a sensor or ionic conductor.
The HI 4011 requires a separate reference electrode to com-
plete its electrolytic circuit. The HI 4111 incorporates a
reference electrode. The Silver Iodide pellet is practically
insoluble in the test solutions being measured and pro-
duces a potential change due to changes in the sample’s
ion activity. When the ionic strength of the sample is fixed
by the addition of ISA, the voltage is proportional to the
concentration of iodide ions in solution and the electrode
follows the Nernst equation.
E= Ea + 2.3 RT/nF log A ion
E= observed potential
Ea= Reference and fixed internal voltages
R= gas constant (8.314 volt coulomb/K Mole)
n= Charge on ion (1-)
A i=ion activity in sample
T= absolute temperature in K
F= Faraday constant (9.648 x 104 coulomb/mole)

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IV.IV.
IV.IV.
IV. Design elements of the HI 4011and HI 4111Design elements of the HI 4011and HI 4111
Design elements of the HI 4011and HI 4111Design elements of the HI 4011and HI 4111
Design elements of the HI 4011and HI 4111
electrodeselectrodes
electrodeselectrodes
electrodes
Upper Cap
Spring
O-Ring
Ceramic Junction
on Inner Stem
Fill Hole
O-Ring and
Plug
Sensing
Membrane
Outer Sleeve
Upper
Threads
Liquid junction
IODIDE
HI 4011
Cap
Sensing
Membrane
Sensor
Handle

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V.V.
V.V.
V. Equipment required:Equipment required:
Equipment required:Equipment required:
Equipment required:
•Hanna HI 5315 Double Junction Reference Electrode
with HI 7072 Fill Solution for HI 4011.
•Hanna HI 4222 pH/ISE/mV meter or other suitable
ion or pH/mV meter. (Note: log/linear graph paper is
useful if an ISE (ion) meter is not available).
•Hanna HI 180 Magnetic Stirrer or equivalent with TFE
coated stirring bars (HI 731320). Note: isolate bea-
kers from stirrer motor heat by placing insulating
material such as foam or cork between them.
•Hanna HI 76404 Electrode Holder or equivalent.
•Plastic beakers (HI 740036P) or other suitable mea-
surement vessel.
VI.VI.
VI.VI.
VI. Solutions RequiredSolutions Required
Solutions RequiredSolutions Required
Solutions Required for Iodide Measurementsfor Iodide Measurements
for Iodide Measurementsfor Iodide Measurements
for Iodide Measurements
0.1 M Iodide Standard, 500 mL HI 4011-01
ISA, 500 mL HI 4000-00
For Molar solutions:
Using volumetric pipettes and glassware make serial dilu-
tions to approximately bracket the concentration of the
samples. Standards with concentrations <10-3 M should
be prepared daily.
Two mL of Hanna ISA for Halide electrodes (HI 4000-00)
should be added to 100 mL of sample or standard.
For ppm solutions:
Prepare 1269 ppm iodide standard by diluting HI 4011-
01: Pipette 100 mL standard to a 1 liter volumetric flask.
Add deionized water to volume. Using additional volumet-
ric pipettes and glassware make serial dilutions of this
1269 ppm standard to approximately bracket the concen-
tration of the samples. Standards with concentrations
<127 ppm should be prepared daily.
Two mL of Hanna ISA for Halide electrodes (HI 4000-00)
should be added to 100 mL of sample or standard.

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VIIVII
VIIVII
VII. General GuidelinesGeneral Guidelines
General GuidelinesGeneral Guidelines
General Guidelines
•Calibration standards and sample solutions should
have the same ionic strength. ISA should be added to
both samples and standards in the same ratio. 1 part
ISA to 50 parts standard is the normal dosing.
•Concentrated samples (>1 M) should be diluted
before measurement. Multiply the final result by the
corresponding dilution factor.
•For high ionic strength samples, prepare standards
with similar ionic strength by increasing the quantity
of ISA used or use standard addition or titration.
•Calibration standards and sample solutions should
be at same temperature.
•The magnetic stirrer may generate heat. Thermally
insulate beaker containing standard or sample from
magnetic stirrer by placing cork or other insulative
sheet between beaker and stirrer plate.
•Calibration standards and sample solutions should
be stirred at the same rate using identical sized TFE
coated stir bars.
•Rinse electrode pair with distilled or deionized water
between samples and gently dab dry with soft dis-
posable absorbent toweling. Do not rub electrodes.
•Presoaking Iodide sensor in a dilute standard will
optimize response. Use concentrations approximately
10-3 M or less.
•A scratched, pitted, or tarnished pellet surface can
cause drift, a loss of low level response, or poor repeat-
ability. Optimum response can be restored by remov-
ing the damaged surface with the microabrasive strip
HI 4000-70.
•Avoid large changes in temperature (thermal shock)
as it may damage the sensor.
•Gas bubbles may form from solution out-gassing due
to temperature change. Gently tap body of sensor to
dislodge them from membrane surface.

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HI 4011
•Remove protective cover from sensor tip.
•Prepare HI 5315 reference electrode by filling electro-
lyte reservoir with HI 7072 fill solution.
•Place sensor and reference electrodes into electrode
holder and connect cable connectors to meter.
HI 4111
•Remove the protective plastic wrap that covers the
ceramic junction before assembling sensor for the first
time.
•HI 7072 reference fill solution should be added daily
to electrolyte reservoir before electrode use.
•During measurement always operate electrode with
the fill hole open.
•During normal use, fill solution will slowly drain out
of the tapered cone junction at the lower portion of the
electrode. Excessive loss (>4 cm drop within 24 hours)
is not normal. If this occurs verify cap is tightened and
the interface between the internal cone and outer
body is free of debris.
•Add fill solution daily to maintain a good head pres-
sure. For optimum response, this level should be main-
tained and not be allowed to drop more than 2-3 cm
(1-inch) below fill hole. It must cover the ceramic
found on the inner stem.
•If an erratic measurement occurs, check to see if for-
eign matter is seen trapped near the internal cone.
Drain and refill with fresh fill solution.

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VIII.VIII.
VIII.VIII.
VIII. Electrode PreparationElectrode Preparation
Electrode PreparationElectrode Preparation
Electrode Preparation
HI 4011
1. Remove protective cover from sensor tip.
2. Prepare reference electrode by filling outer electrolyte
reservoir with HI 7072.
3. Place sensor and reference electrodes into electrode
holder and connect cable connectors to meter.
HI 4111
1. Unwrap plastic film seal found over ceramic junction
on inner stem and discard. This is only used for ship-
ping and long term storage.
2. Rinse inner stem with deionized water making certain
to wet the o-ring found on the inner stem.
3. Reassemble electrode by gently pushing the inner
assembly into the outer body, sliding spring down
cable, and screwing cap into place.
4. Remove fill hole cover and o-ring on fill hole spout.
5. Using the dropper pipette provided, add a few drops
HI 7072 fill solution to the electrode, wetting the o-
ring and rinsing out the fill solution chamber.
Deionized
Water
Remove
Parafilm

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6. Holding the body of the electrode gently press upper
cap with your thumb. This permits the fill solution to
drain out of the body. Release cap and verify elec-
trode returns to its original position. (You may need to
gently assist for this to occur).
7. Tighten the electrode cap onto the body and fill elec-
trode body until fill solution volume is just below fill
hole.
8. Position electrode in a Hanna HI 76404 electrode
holder (or equivalent) and connect plug to meter.
HI 4111
IODIDE
COMBINATION

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IX.IX.
IX.IX.
IX. Quick Check of Electrode SlopeQuick Check of Electrode Slope
Quick Check of Electrode SlopeQuick Check of Electrode Slope
Quick Check of Electrode Slope
•Connect sensors to pH/mV/ISE meter
•Place meter in mV mode.
•Place 100 mL of DIW into a beaker with stir bar.
•Place electrodes into prepared sample.
•Add 1 mL of a standard 0.1 M (12690 ppm) stan-
dard to beaker. Record the mV value when stable.
•Add an additional 10 mL of standard to the solution.
Record the mV when reading has stabilized. This
value should be less than the previous noted (more
negative).
•Determine the difference between the two mV values.
An acceptable value for this slope is -56 ± 4 mV.
X.X.
X.X.
X. Corrective actionCorrective action
Corrective actionCorrective action
Corrective action
•Verify protective cap has been removed (HI 4011).
•Verify plastic film has been removed from inner stem
(HI 4111).
•Verify electrodes are connected properly to meter and
meter is powered.
•Verify dilute standards are freshly made and stored.
Remake solutions if appropriate.
•If the sensor slope just misses the suggested slope
window, soaking the sensor in a dilute standard may
solve the problem. (<10-3 M Iodide or <126 ppm
standard).
•A scratched sensing surface can be polished with HI
4000-70 polishing strip. Cut off approximately 1
inch of the micro-abrasive strip. Wet the frosted side
with deionized water and place against damaged
membrane of the electrode. Place your thumb against
the shiny backing and slowly rotate back and forth
while applying gentle pressure. Continue polishing
until you are satisfied with the surface. If dark depos-
its appear on polishing strip move the paper slightly
and continue polishing.