Water Determination in Paper with Potentiometric Method

Equipment

Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0338.100 double Pt electrode; input Pol

Reagents

HYDRANAL® Composite 5; D0

Sample

20 -30 mL methanol, conditioned to complete dryness
1.000 mL sample solution
extract app. 1.0g of paper (cut in small pieces) in 50 mL methanol (extraction medium)

Remarks

Calculations:

Water=(EP1-C38)*C39*C01/C00/C02;2;%

smpl size 0.02003 g
EP1 0.2260 ml
Water 5.29 %
Titer 5.0058 mg/ml
Blank 0.0145 ml
Water = content of water in paper in %
C00 = sample size / aliquot (1.0015 g / 50 mL = 0.02003 g/mL)
C01 = factor for % (0.1)
C02 = divisor (1)
C38 = blank value in mL of “Blank_KF“ method (0.0145 mL)
C39 = titer of HYDRANAL® Composite 5

Answer

Water = (0.2260-0.0145) x 5.0058 x 0.1 / 0.02003 / 1 = 5.29%

Mean from 3 determinations.
This method can be generally used for KF titrations with blank values.

· Adjust the calculation values C01 and C02 according the desired result unit and your sample size:

Unit RS Smpl size

Sample preparation:

Stir sample solution for app. ½ h to extract the water and take aliquots (see calculation).

Literature

Water determination by Karl Fisher titration, G. Wieland, GIT Verlag, Darmstadt (Germany)
HYDRANAL®, practical course, Water reagents according to Eugen Scholz, Riedel de Haën, Seelze (Germany)
Metrohm Application Bulletin No. 77: KF water determination

Blank Determination of Methanol with Potentiometric Method

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0338.100 double Pt electrode; input Pol

Reagents
HYDRANAL® Composite 5; D0
Sample

20 -30 mL methanol, conditioned to complete dryness
1.000 mL methanol (extraction medium)

Remarks
Calculations:

Blank=EP1

Blank = blank of methanol (extraction medium)

Blank= 0.0145 mL

EP1 = 0.0145 mL

Common variables
C38 = MN1
Mean from 2-3 determinations.
This method can be generally used for KF blank determinations. For work with a KF Oven, you need an extraction time. Enter it in key , >titration parameters.

Use the same control parameters for the blank determination as for

the sample titrations.

For automatic curve output add in , >report “curve“.

Literature

Water determination by Karl Fisher titration, G. Wieland, GIT Verlag,Darmstadt (Germany)HYDRANAL®, practical course, Water reagents according to Eugen Scholz, Riedel de Haën, Seelze (Germany) Metrohm Application Bulletin No. 77: KF water determination

Method documentation

'pa
751 GPD Titrino 15215 751.0010
date 97-03-12 time 10:46 11
KFT Ipol Blank_KF
parameters
control parameters
EP at U 250 mV
dynamics 100 mV
max.rate max. ml/min
min.volume incr. min. ml
stop crit: drift
stop drift 20 ml/min
>titration parameters
titr.direction: -
pause 1 0 s
start V: OFF
pause 2 0 s
extr.time 0 s
dos.element: internal D0
I(pol) 50 mA
electrode test: OFF
temperature 25.0 °C
time interval 2 s
>stop conditions
stop V: abs.
stop V 99.99 ml
filling rate max. ml/min
>statistics
status: ON
mean n= 3
res.tab: original
>preselections

conditioning: ON
display drift: ON
drift corr: OFF
req.ident: OFF
req.smpl size: OFF
activate pulse: OFF
------------
'de
751 GPD Titrino 15215 751.0010
date 97-03-12 time 10:46
KFT Ipol Blank_KF
def
>formula

Blank=EP1

RS1 text Blank
RS1 decimal places 4
RS1 unit: ml
>silo calculations
match id: OFF
>common variables
C38=MN1
>report
report COM1:full;
>mean
MN1=RS1
>temporary variables
------------
'fr
751 GPD Titrino 15215 751.0010
date 97-03-12 time 10:45 11
KFT Ipol Blank_KF
EP1 0.0145 ml
Blank 0.0145 ml
mean( 2) +/-s s/%
Blank 0.0145 0.00000 ml 0.00
============
'cu
751 GPD Titrino 15215 751.0010
date 97-03-12 time 10:45 11
KFT IpolBlank_KF
2.0 s/div dV=0.05 ml/div
============
'st

751 GPD Titrino 15215 751.0010

date 97-03-12 time 10:46
statistics
## Blank
1 0.0145
2 0.0145
mean( 2) +/-s s/%
Blank 0.0145 0.00000 ml 0.00

Blank Determination of Methanol with Potentiometric Method

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0338.100 double Pt electrode; input Pol

Reagents
HYDRANAL® Composite 5; D0
Sample

20 -30 mL methanol, conditioned to complete dryness
1.000 mL methanol (extraction medium)

Remarks
Calculations:

Blank=EP1

Blank = blank of methanol (extraction medium)

Blank= 0.0145 mL

EP1 = 0.0145 mL

Common variables
C38 = MN1
Mean from 2-3 determinations.
This method can be generally used for KF blank determinations. For work with a KF Oven, you need an extraction time. Enter it in key , >titration parameters.

Use the same control parameters for the blank determination as for

the sample titrations.

For automatic curve output add in , >report “curve“.

Literature

Water determination by Karl Fisher titration, G. Wieland, GIT Verlag,Darmstadt (Germany)HYDRANAL®, practical course, Water reagents according to Eugen Scholz, Riedel de Haën, Seelze (Germany) Metrohm Application Bulletin No. 77: KF water determination

Method documentation

'pa
751 GPD Titrino 15215 751.0010
date 97-03-12 time 10:46 11
KFT Ipol Blank_KF
parameters
control parameters
EP at U 250 mV
dynamics 100 mV
max.rate max. ml/min
min.volume incr. min. ml
stop crit: drift
stop drift 20 ml/min
>titration parameters
titr.direction: -
pause 1 0 s
start V: OFF
pause 2 0 s
extr.time 0 s
dos.element: internal D0
I(pol) 50 mA
electrode test: OFF
temperature 25.0 °C
time interval 2 s
>stop conditions
stop V: abs.
stop V 99.99 ml
filling rate max. ml/min
>statistics
status: ON
mean n= 3
res.tab: original
>preselections

conditioning: ON
display drift: ON
drift corr: OFF
req.ident: OFF
req.smpl size: OFF
activate pulse: OFF
------------
'de
751 GPD Titrino 15215 751.0010
date 97-03-12 time 10:46
KFT Ipol Blank_KF
def
>formula

Blank=EP1

RS1 text Blank
RS1 decimal places 4
RS1 unit: ml
>silo calculations
match id: OFF

>common variables

C38=MN1

>report

report COM1:full;

>mean

MN1=RS1

>temporary variables

------------

'fr

751 GPD Titrino 15215 751.0010

date 97-03-12 time 10:45 11

KFT Ipol Blank_KF

EP1 0.0145 ml

Blank 0.0145 ml

mean( 2) +/-s s/%

Blank 0.0145 0.00000 ml 0.00

============

'cu

751 GPD Titrino 15215 751.0010

date 97-03-12 time 10:45 11

KFT IpolBlank_KF

2.0 s/div dV=0.05 ml/div

============

'st

751 GPD Titrino 15215 751.0010

date 97-03-12 time 10:46

statistics

## Blank

1 0.0145

2 0.0145

mean( 2) +/-s s/%

Blank 0.0145 0.00000 ml 0.00

Blank Determination of Methanol with Potentiometric Method

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0338.100 double Pt electrode; input Pol

Reagents
HYDRANAL® Composite 5; D0
Sample

20 -30 mL methanol, conditioned to complete dryness
1.000 mL methanol (extraction medium)

Remarks
Calculations:

Blank=EP1

Blank = blank of methanol (extraction medium)

Blank= 0.0145 mL

EP1 = 0.0145 mL

Common variables
C38 = MN1
Mean from 2-3 determinations.
This method can be generally used for KF blank determinations. For work with a KF Oven, you need an extraction time. Enter it in key , >titration parameters.

Use the same control parameters for the blank determination as for

the sample titrations.

For automatic curve output add in , >report “curve“.

Literature

Water determination by Karl Fisher titration, G. Wieland, GIT Verlag,Darmstadt (Germany)HYDRANAL®, practical course, Water reagents according to Eugen Scholz, Riedel de Haën, Seelze (Germany) Metrohm Application Bulletin No. 77: KF water determination

Method documentation

'pa
751 GPD Titrino 15215 751.0010
date 97-03-12 time 10:46 11
KFT Ipol Blank_KF
parameters
control parameters
EP at U 250 mV
dynamics 100 mV
max.rate max. ml/min
min.volume incr. min. ml
stop crit: drift
stop drift 20 ml/min
>titration parameters
titr.direction: -
pause 1 0 s
start V: OFF
pause 2 0 s
extr.time 0 s
dos.element: internal D0
I(pol) 50 mA
electrode test: OFF
temperature 25.0 °C
time interval 2 s
>stop conditions
stop V: abs.
stop V 99.99 ml
filling rate max. ml/min
>statistics
status: ON
mean n= 3
res.tab: original
>preselections

conditioning: ON
display drift: ON
drift corr: OFF
req.ident: OFF
req.smpl size: OFF
activate pulse: OFF
------------
'de
751 GPD Titrino 15215 751.0010
date 97-03-12 time 10:46
KFT Ipol Blank_KF
def
>formula

Blank=EP1

RS1 text Blank
RS1 decimal places 4
RS1 unit: ml
>silo calculations
match id: OFF
>common variables
C38=MN1
>report
report COM1:full;
>mean
MN1=RS1
>temporary variables
------------
'fr
751 GPD Titrino 15215 751.0010
date 97-03-12 time 10:45 11
KFT Ipol Blank_KF

EP1 0.0145 ml

Blank 0.0145 ml

mean( 2) +/-s s/%

Blank 0.0145 0.00000 ml 0.00

============

'cu

751 GPD Titrino 15215 751.0010

date 97-03-12 time 10:45 11

KFT IpolBlank_KF

2.0 s/div dV=0.05 ml/div

============

'st

751 GPD Titrino 15215 751.0010

date 97-03-12 time 10:46

statistics

## Blank

1 0.0145

2 0.0145

mean( 2) +/-s s/%

Blank 0.0145 0.00000 ml 0.00

KF Titer Determination with Water by Potentiometric Method

KF Titer Determination with Water by Potentiometric Method

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0338.100 double Pt electrode; input Pol

Reagents
HYDRANAL® Composite 5; D0

Sample
20 -30 mL methanol, conditioned to complete dryness
10 μL dist. water

Remarks
Calculations:

Titer=C00/EP1*C01;4;mg/ml

Titer = titer of HYDRANAL® Composite 5
C01 = factor (1000 if water is used as standard; if methanol is used, enter its water content in mg/mL)

Answer

Titer = 0.010 / 1.9975 x 1000 = 5.0063 mg/mL

EP1 = 1.9975 mL
C00 = 1000

Common variables
C39 = MN1
Mean from 5 determinations.
Water or methanol standard can be injected either with a microliter syringe or with any syringe and reweighed.
Adjust the calculation value C01 according to your sample size: water
C00 in g C01=1000
C00 in mL C01=Density of H2O [mg/mL] 1
Methanol standard
C00 in mL C01=Content of methanol [mg/mL]
C00 in mL C01=0.001 * content of methanol [mg/mL]
For automatic curve output add in , >report “curve“.

Literature
Water determination by Karl Fisher titration, G. Wieland, GIT Verlag, Darmstadt (Germany)
HYDRANAL®, practical course, Water reagents according to Eugen
Scholz, Riedel de Haën, Seelze (Germany)
Metrohm Application Bulletin No. 77: KF water determination

Method documentation

'pa
751 GPD Titrino 15215 751.0010
KFT Ipol H2OTiter
parameters
>control parameters
EP at U 250 mV
dynamics 100 mV
max.rate max. ml/min
min.volume incr. min. ml
stop crit: drift
stop drift 20 ml/min
>titration parameters
titr.direction: -
pause 1 0 s
start V: OFF
pause 2 0 s
extr.time 0 s
dos.element: internal D0
I(pol) 50 mA
electrode test: OFF
temperature 25.0 °C
time interval 2 s
>stop conditions
stop V: abs.
stop V 99.99 ml
filling rate max. ml/min
>statistics
status: ON
mean n= 5
res.tab: original
>preselections
conditioning: ON
display drift: ON
drift corr: OFF
req.ident: OFF
req.smpl size: value
activate pulse: OFF
------------
'fm
751 GPD Titrino 15215 751.0010
KFT Ipol H2OTiter
>calculations
Titer=C00/EP1*C01;4;mg/ml

C00= 0.010
C01= 1000
------------
'fr
751 GPD Titrino 15215 751.0010
KFT Ipol H2OTiter
smpl size 0.010 g
EP1 1.9975 ml
Titer 5.0063 mg/ml
mean( 5) +/-s s/%
Titer 5.0058 0.00287 mg/ml 0.06
============
'cu
751 GPD Titrino 15215 751.0010
KFT IpolH2OTiter
10.0 s/div dV=0.5 ml/div
============
'st
751 GPD Titrino 15215 751.0010
statistics
## Titer
1 5.0050
2 5.0075
3 5.0013
4 5.0088
5 5.0063
mean( 5) +/-s s/%
Titer 5.0058 0.00287 mg/ml 0.06

KF Titer Determination with Sodium Tartrat by Potentiometric Method

KF Titer Determination with Sodium Tartrate by Potentiometric Method

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0338.100 double Pt electrode; input Pol

Reagents
HYDRANAL® Titrant 5; D0

Sample
20 -30 mL HYDRANAL® Solvent, conditioned to complete dryness app. 200 mg di-Sodium tartrate dihydrate
Water 15.66 ±0.05%

Remarks
Calculations:

Titer=C00/EP1*C01;4;mg/ml

Titer = titer of HYDRANAL® Titrant 5
C01 = water content * 10 (156,6)

Answer

Titer= 0.2294 / 7.508 x 156.6 = 4.7848 mg/mL

EP1 = 7.508 mL
C00 = 0.2294 g

Common variables
C39 = MN1
Mean from 5 determinations.
Reweigh the sodium tartrate in a weighing boat.
Adjust the calculation value C01 according to the unit of your sample
weight:

C00 in g C01=156.6
C00 in mg C01=0.1566
For automatic curve output add in , >report “curve“.

Literature
Water determination by Karl Fisher titration, G. Wieland, GIT Verlag,
Darmstadt (Germany)
HYDRANAL®, practical course, Water reagents according to Eugen
Scholz, Riedel de Haën, Seelze (Germany)
Metrohm Application Bulletin No. 77: KF water determination

Method documentation

'pa
751 GPD Titrino 15215 751.0010
KFT Ipol TarTiter
parameters
>control parameters
EP at U 250 mV
dynamics 100 mV
max.rate max. ml/min
min.volume incr. min. ml
stop crit: drift
stop drift 20 ml/min
>titration parameters
titr.direction: -
pause 1 0 s
start V: OFF
pause 2 0 s
extr.time 0 s
dos.element: internal D0
I(pol) 50 mA
electrode test: OFF
temperature 25.0 °C
time interval 2 s
>stop conditions
stop V: abs.
stop V 99.99 ml
filling rate max. ml/min
>statistics
status: ON
mean n= 5
res.tab: original
>preselections
conditioning: ON
display drift: ON
drift corr: OFF
req.ident: OFF
req.smpl size: value
activate pulse: OFF
------------
'fm
751 GPD Titrino 15215 751.0010
KFT Ipol TarTiter
>calculations

Titer=C00/EP1*C01;4;mg/ml

C00= 0.2294
C01= 156.6
------------
'fr
751 GPD Titrino 15215 751.0010
KFT Ipol TarTiter

smpl size 0.2294 g
EP1 7.508 ml
Titer 4.7848 mg/ml
mean( 5) +/-s s/%
Titer 4.7893 0.00506 mg/ml 0.11
============
'cu
751 GPD Titrino 15215 751.0010
KFT IpolTarTiter
20.0 s/div dV=2.0 ml/div
============
'st
751 GPD Titrino 15215 751.0010
statistics
## Titer
1 4.7936
2 4.7939
3 4.7830
4 4.7910
5 4.7848
mean( 5) +/-s s/%
Titer 4.7893 0.00506 mg/ml 0.11

Analysis of Spinning Bath with Potentiometric Method

Analysis of Spinning Bath With Potentiometric Method

Reagents
c(NaOH) = 0.1 mol/L; D0

Sample
0.1 mL c(ZnSO4) ≅ 0.1 mol/L in c(H2SO4) ≅ 1 mol/L
25 mL dist. water

Electrodes
6.0232.100 combined pH glass electrode; input 1

Remarks
• EP1: H₂SO₄ + 2OH^- ⇒ SO4 ^2- + 2H₂O

EP2: Zn²⁺ + 2 OH^- ⇒ Zn(OH)₂ (s)

Calculations:
H2SO4 = concentration of H2SO4 in g/L
ZnSO4 = concentration of ZnSO4 in g/L
C01 = concentration of titrating agent (0.1 mol/L)
C02 = molecular mass of H2SO4 (98.08 g/mol)
C03 = molecular mass of ZnSO4 (161.23 g/mol)
C04 = factor for “normality“ (2)
• For automatic curve output add in , >report “curve“.

Literature
Metrohm's Teachware on CD-ROM

Method documentation

'pa
751 GPD Titrino...15215...751.0010
SET pH...Spinning
parameters
>SET1
EP at pH...5.50
dynamics...3
max.rate ...5 ml/min
min.rate...1 μl/min
stop crit:...drift
stop drift ...20 μl/min
>SET2
EP at pH...9.50
dynamics...4
max.rate...1 ml/min
min.rate ...1 μl/min
stop crit:... drift
stop drift ... 20 μl/min
>titration parameters
titr.direction:...auto
pause 1... 0s
start V: ...OFF
pause 2...0s
extr.time... 0s
dos.element:...internal D0
meas.input:...1
temperature...25.0 °C
time interval...2s
>stop conditions
stop V:... abs.
stop V...99.99 ml
filling rate...max. ml/min
>statistics
status:...OFF
>preselections
conditioning:...OFF
req.ident:...OFF
req.smpl size:...OFF
activate pulse:...OFF
------------
'fm
751 GPD Titrino 15215 751.0010
SET pH...Spinning
>calculations

H₂SO₄=EP1*C01*C02/C04/C00;2;g/l
ZnSO₄=(EP2-EP1)*C01*C03/C04/C00;2;g/l

C00= 0.1
C01= 0.1
C02= 98.93
C03= 161.23
C04= 2
------------
'fr
751 GPD Titrino 15215 751.0010
pHc(init) 2.22 SET pH Spinning
smpl size 0.1 ml
EP1 2.011 ml 5.61
EP2 2.245 ml 9.53
H2SO4 99.47 g/l
ZnSO4 18.86 g/l
============
'cu
751 GPD Titrino 15215 751.0010
SET pH Spinning
20.0 s/div dV=0.5 ml/div

Potentiometric Determination of Kappa Number of Paper Pulp

Potentiometric Determination of Kappa Number of Paper Pulp

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0418.120 combined massive Pt electrode; input 1

Reagents
c(1/2Na2S2O3) = 0.2 mol/L; D0

Sample
13 g cellulose pulp
780 mL dist. water
100 mL c(1/5KMnO4) = 0.1 mol/L
100 mL c(1/2H2SO4) = 4 mol/L
20 mL dist. water
35 mL w(KI) = 0.10 (10%)

Remarks
The Kappa number is the consumption of c(1/5KMnO4) = 0.1 mol/L in mL. The results are corrected to the consumption of 50% of thepermanganate solution added.
Determine the dry content of the sample: Dry sample at 105 °C for app. 90 minutes. Calculate the dry content in % and enter it ascalculation value C03.
Weigh in an appropriate amount of sample. Add 780 mL of dist.water and defibrate it with the stirrer. Add the mixture of 100 mLc(1/5KMnO4) = 0.1 mol/L und100 mL c(1/2H2SO4) = 4 mol/L as quickly as possible and rinse with 20 mL dist. water. Add 35 mL w(KI) = 0.10 (10%) after a waiting time of exactly 10 minutes to stop the reaction. Titrate immediately. Treat the blank sample in the same way as above. The waiting time may be programmed in the Titrino; the additions can be carried out automatically using a TIP.

Calculations:

p=(C02-EP1)*C04/C05;1;
KappaNo=RS1*C01*C06/C00/C03;1;

p = consumption of c(1/5KMnO4) = 0.1 mol/L in mL
KappaNo = Kappa number
C01 = factor for correction to a 50 % permanaganate consumption,
see table below (p.e. 59.3 1.020)
C02 = mL of c(1/2Na2S2O3) = 0.2 mol/L consumption of blank sample
C03 = dry content in % (p.e. 21.519)
Titratration of c(1/2Na2S2O3) = 0.2 mol/L (0.2) or percent of permanaganate consumption (0.1)
C06 = factor to compensate for entry of dry content in % (100)

Answer

p= (0.2-19.672) x 0.2 / 0.1 = 59.3
KappaNo= 59.3 x 1.020 x 100 / 13.0051 / 21.519 = 21.6

EP1 = 19.672 mL
C00 = 13.0051 g

C01 can only be entered after the titration, because the p value is necessary. Recalculate and print another full report.
Table for correction of 50% of the permanganate solution:

p…… 0.. …1....... 2 .......3 …...4……. 5……. 6…… 7…… 8….. 9

30 0.958 0.960 0.962 0.964 0.966 0.968 0.970 0.973 0.975 0.977

40 0.979 0.981 0.983 0.985 0.987 0.989 0.991 0.994 0.996 0.998

50 1.000 1.002 1.004 1.006 1.009 1.011 1.013 1.015 1.017 1.019

60 1.022 1.024 1.026 1.028 1.030 1.033 1.035 1.037 1.039 1.042

70 1.044

Literature


• TAPPI T236 os-76
• Metrohn’s Teachware on CD-ROM

Method documentation

'pa
751 GPD Titrino 15215 751.0010
DET U KappaNo
parameters
>titration parameters
meas.pt.density… 4
min.incr. ….10.0 ml
dos.rate max….. ml/min
signal drift ….50 mV/min
equilibr.time …26 s
start V: ….OFF
pause ….0 s
dos.element:…. internal D0
meas.input:… 1
temperature…. 25.0 °C
>stop conditions
stop V:…. abs.
stop V…. 40 ml
stop U ….OFF mV
stop EP… 9
filling rate max…. ml/min
>statistics
status:…. OFF
>evaluation
EPC….. 5
EP recognition: all
fix EP1 at U ….OFF mV
pK/HNP:…. OFF
>preselections
req.ident:…. OFF
req.smpl size: value
activate pulse:…. OFF
------------
'fm
751 GPD Titrino 15215 751.0010
DET U KappaNo
>calculations

p=(C02-EP1)*C04/C05;1;
KappaNo=RS1*C01*C06/C00/C03;1;

C00= 13.0051
C01= 1.020
C02= 49.339
C03= 21.519
C04= 0.2
C05= 0.1
C06= 100
------------
'fr
751 GPD Titrino 15215 751.0010
U(init) 416 mV DET U KappaNo
smpl size ….13.0051 g
EP1…. 19.672 ml ….325 mV
p… 59.3
KappaNo …0.0
stop V reached
============
'cu
751 GPD Titrino 15215 751.0010
start V 0.000 ml DET U KappaNo
5.0 ml/div dU=50.0 mV/div
============
'fr
751 GPD Titrino 15215 751.0010
U(init) 416 mV DET U KappaNo
smpl size ….13.0051 g
EP1 ….19.672 ml ….325 mV
p…. 59.3
KappaNo… 21.6
stop V reached
-----------

Potentiometric Determination of Silver in Film Emulsions

Potentiometric Determination of Silver in Film Emulsions

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0430.100 Ag Titrode with Ag2S coating; input 1

Reagents
c(Thioacetamide) = 0.025 mol/L in buffer pH = 5

Sample
10 mL solution (100 cm2 Ilford black and white film in 100 mL fixing agent Na2S2O3 300 g/L)
20 mL c(NaOH) = 2 mol/L
20 mL c(EDTA) = 0.1 mol/L
10 mL w(gelatine) = 0.12 (12%)

Remarks
Determination reaction:

S O

CH3C + OH+ + 2 Ag+ ........CH3C + Ag2S (s) + H+

NH2 NH2

Calculations:

AgNO3=EP1*C01*C02/C00*C03/C04/C05;3;g/m2

AgNO3 = amount of AgNO3 in g/m2
C01 = concentration of titrating agent (0.025 mol/L)
C02 = molecular mass of AgNO3 (169.87 g/mol)
C03 = factor for 100 mL sample (100)
C04 = size of sample (0.01 m2)
C05 = conversion mL to L (1000)

Answer

AgNO₃=0.987 x 0.025 x 169.87 / 10 x 100 / 0.01 / 1000 = 4.192 g/m²

EP1 = 0.987 mL
C00 = 10.00 mL
EDTA keeps silver in solution and gelatine prevents the precipitation from massing together.

Ag2S coating of electrode:
Keep Ag Titrode in alkaline solution of thioacetamide during 15 min.

Buffer pH = 5:
Mix potassium biphthalate solution, c = 0.1 mol/L with Na3PO4 solution, c = 0.05 mol/L. Ratio 50:24. Dissolve 0.5 g thymol per liter buffer solution.

Titrating agent:
Dissolve 1.9 g Thioacetamide in 1 L buffer pH = 5 solution.

Gelatine solution:

Dissolve 12 g gelatine in hot water, add 0.5 g thymol, allow to cool and add up to 1 L.

Literature
Metrohm Application Bulletin No. 72: Potentiometric determination of mercury or silver in the presence of halide ions.

Method documentation

'pa
751 GPD Titrino 15215 751.0010
DET U Film Ag
parameters
>titration parameters
meas.pt.density… 4

min.incr. …10.0 ml
dos.rate max…. ml/min
signal drift …20 mV/min
equilibr.time …38 s
start V: …OFF
pause …0 s
dos.element:… internal D0
meas.input: …1
temperature …25.0 °C
>stop conditions
stop V: …abs.
stop V …3 ml
stop U… OFF mV
stop EP …9
filling rate max…. ml/min
>statistics
status: …OFF
>evaluation
EPC… 5
EP recognition: all
fix EP1 at U… OFF mV
pK/HNP:…. OFF
>preselections
req.ident:… OFF
req.smpl size:… OFF
activate pulse:…. OFF
------------
'fm
751 GPD Titrino 15215 751.0010
DET U Film Ag
>calculations

AgNO3=EP1*C01*C02/C00*C03/C04/C05;3;g/m2

C00= 10.0
C01= 0.025
C02= 169.87
C03= 100
C04= 0.01
C05= 1000
------------
'fr
751 GPD Titrino 15215 751.0010
U(init) -17 mV DET U Film Ag
smpl size.. 10.0 ml id#1 ILFORD
EP1… 0.987 ml…. 52 mV
AgNO3 ….4.192 g/m2
stop V reached
============
'cu
751 GPD Titrino 15215 751.0010
start V 0.000 ml DET U Film Ag
2.0 ml/div dU=50.0 mV/div

Potentiometric Determination of Silver in Film Emulsions

Potentiometric Determination of Silver in Film Emulsions

Equipment

Potentiometer = 751 GPD Titrino / Titroprocessor

Electrodes = 6.0430.100 Ag Titrode with Ag2S coating; input 1

Reagents

c(Thioacetamide) = 0.025 mol/L in buffer pH = 5

Sample

10 mL solution (100 cm2 Ilford black and white film in 100 mL fixing

agent Na2S2O3 300 g/L)

20 mL c(NaOH) = 2 mol/L

20 mL c(EDTA) = 0.1 mol/L

10 mL w(gelatine) = 0.12 (12%)

Remarks

Determination reaction:

S O

CH3C + OH+ + 2 Ag+ CH3C + Ag2S (s) + H+

NH2 NH2

Calculations:

AgNO3=EP1*C01*C02/C00*C03/C04/C05;3;g/m2

AgNO3 = amount of AgNO3 in g/m2

C01 = concentration of titrating agent (0.025 mol/L)

C02 = molecular mass of AgNO3 (169.87 g/mol)

C03 = factor for 100 mL sample (100)

C04 = size of sample (0.01 m2)

C05 = conversion mL L (1000)

Answer

AgNO₃=0.987 x 0.025 x 169.87 / 10 x 100 / 0.01 / 1000 = 4.192 g/m²

EP1 = 0.987 mL

C00 = 10.00 mL

EDTA keeps silver in solution and gelatine prevents the precipitation from massing together.

Ag2S coating of electrode:

Keep Ag Titrode in alkaline solution of thioacetamide during 15 min.

Buffer pH = 5:

Mix potassium biphthalate solution, c = 0.1 mol/L with Na3PO4 solution, c = 0.05 mol/L. Ratio 50:24. Dissolve 0.5 g thymol per liter buffer solution.

Titrating agent:

Dissolve 1.9 g Thioacetamide in 1 L buffer pH = 5 solution.

Gelatine solution:

Dissolve 12 g gelatine in hot water, add 0.5 g thymol, allow to cool and add up to 1 L.

Literature

Metrohm Application Bulletin No. 72: Potentiometric determination of mercury or silver in the presence of halide ions.

Method documentation

'pa

751 GPD Titrino 15215 751.0010

DET U Film Ag

parameters

>titration parameters

meas.pt.density… 4

min.incr. …10.0 ml

dos.rate max…. ml/min

signal drift …20 mV/min

equilibr.time …38 s

start V: …OFF

pause …0 s

dos.element:… internal D0

meas.input: …1

temperature …25.0 °C

>stop conditions

stop V: …abs.

stop V …3 ml

stop U… OFF mV

stop EP …9

filling rate max…. ml/min

>statistics

status: …OFF

>evaluation

EPC… 5

EP recognition: all

fix EP1 at U… OFF mV

pK/HNP:…. OFF

>preselections

req.ident:… OFF

req.smpl size:… OFF

activate pulse:…. OFF

------------

'fm

751 GPD Titrino 15215 751.0010

DET U Film Ag

>calculations

AgNO3=EP1*C01*C02/C00*C03/C04/C05;3;g/m2

C00= 10.0

C01= 0.025

C02= 169.87

C03= 100

C04= 0.01

C05= 1000

------------

'fr

751 GPD Titrino 15215 751.0010

U(init) -17 mV DET U Film Ag

smpl size.. 10.0 ml id#1 ILFORD

EP1… 0.987 ml…. 52 mV

AgNO3 ….4.192 g/m2

stop V reached

============

'cu

751 GPD Titrino 15215 751.0010

start V 0.000 ml DET U Film Ag

2.0 ml/div dU=50.0 mV/div