HI 4108
CUPRIC
COMBINATION
HI 4008
CUPRIC
Instruction Manual
HI 4008HI 4008
HI 4008
HI 4008HI 4008
HI 4108HI 4108
HI 4108
HI 4108HI 4108
Cupric Ion
Selective Electrode
Half-cell
Combination
1
HI 4008 Cupric Half-cellHI 4008 Cupric Half-cell
HI 4008 Cupric Half-cell
HI 4008 Cupric Half-cellHI 4008 Cupric Half-cell
HI 4108 Cupric Combination ElectrodeHI 4108 Cupric Combination Electrode
HI 4108 Cupric Combination Electrode
HI 4108 Cupric Combination ElectrodeHI 4108 Cupric Combination Electrode
I. I.
Introduction:Introduction:
I.
Introduction:
I. I.
Introduction:Introduction:
The Hanna HI 4008 and HI 4108 are ion selective electrodes designed for the measurement of cupric ions in
aqueous solutions. The HI 4008 is a solid state half-cell
sensor that requires a separate reference. The HI 4108 is a
combination ion selective electrode.
IIII
SpecificationsSpecifications
II.
Specifications
IIII
SpecificationsSpecifications
Type: Solid State electrode with
a cupric sulfide /silver sulfide membrane.
Ion(s) measured: Cupric (Cu
++
2
+
++
)
Measurement range: 0.1 M to 1X 10
-6
M
6355 to 0.065 ppm
Interfering ions: Silver and mercury must
be absent. Any ion that forms a more insoluble sulfide than
cupric sulfide will interfere with the electrode response. These
include bismith (Bi3+), iron (Fe2+) ,bromide(Br-) and
chloride (Cl-) if they are in high concentrations. Long term
exposure in this ion will poison the cupric surface. Oxidation
of the cupric surface will also poison the electrode.
Operating Temperature: 0-80°C
Operating pH: 3 to 7 pH
(4-6 recommended)
Dimensions: 12 mm (OD) X 120 mm
nominal insertion
(0.47” X 4.72”)
Connection: BNC
2
III. III.
Theory of OperationTheory of Operation
III.
Theory of Operation
III. III.
Theory of OperationTheory of Operation
::
:
::
The HI 4108 or HI 4108 cupric electrodes are potentiometric
devices used for the rapid determination of free cupric ions
in samples and as a detector for the titration of cupric with
EDTA.
Cupric sensors are “electrodes of the third kind”
because they detect cations which also form low-solubility
salts with sulfide anions that also form low-solubility salts
with silver.
The electrode functions as a sensor or ionic conductor. The
HI 4008 requires a separate reference electrode to complete
its electrolytic circuit. The HI 4108 incorporates a reference
electrode. The mixed cupric sulfide/ silver sulfide membrane produces a potential change due to changes in the
sample’s cupric ion activity. When the ionic strength of the
sample is fixed by the addition of ISA, the voltage is proportional to the concentration of cupric 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 (2+)
A i=ion activity in sample
T= absolute temperature in K
F= Faraday constant (9.648 x 104 coulombs/mole)
3
IV. IV.
Design elements of the HI 4008 and HI 4108Design elements of the HI 4008 and HI 4108
IV.
Design elements of the HI 4008 and HI 4108
IV. IV.
Design elements of the HI 4008 and HI 4108Design elements of the HI 4008 and HI 4108
electrodeselectrodes
electrodes
electrodeselectrodes
Cap
HI 4008
Sensor
Handle
Sensing
Membrane
Upper Cap
Upper
Threads
O-Ring
Ceramic Junction
on Inner Stem
CUPRIC
Spring
Fill Hole
O-Ring and
Plug
Outer Sleeve
Liquid junction
Sensing
Membrane
4
V. V.
Equipment required:Equipment required:
V.
Equipment required:
V. V.
Equipment required:Equipment required:
• Hanna HI 5315 Double Junction Reference Electrode
with HI 7072 Fill Solution for use with HI 4008 halfcell.
• 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 beakers 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.
Solutions RequiredSolutions Required
VI.
Solutions Required
VI. VI.
Solutions RequiredSolutions Required
For Cupric Measurements
0.1 M cupric standard, (500 mL) HI 4008-01
ISA, (500 mL) HI 4000-00
For direct cupric measurements- Using volumetric pipettes
and glassware, make dilutions of HI 4008-01 to bracket
the concentration of the samples. Note: 0.1M cupric standard is equivalent to 6355 ppm. Standards with concentrations < 10
-3
M (63.6 ppm) should be prepared daily.
Store in tightly closed plastic bottle. To 100 parts standard
or sample add 2 mL of ISA.
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