Metrohm 794 Basic Titrino - Manual (Page 178)

6.3. User methods
794 Basic Titrino
174
6.3.10 "EDTA-NTA"
EDTA und NTA in detergents.
Electrode:
6.0502.140 Cu electrode and 6.0726.100
Ag/AgCl reference electrode (outer elcetrolyte
KNO
3
sat.), at measuring input 1.
Titrant:
c(CuNO
3
) = 0.01 mol/L
Sample:
Weigh 0.5 – 1 g sample into a 100 mL meas-
uring flask and add app. 50 mL dist. water.
Heat to app. 40 °C. Allow to cool and fill up to
mark. Pipette 10 mL into a beaker, add 2 mL
EDTA or NTA standard solution (c = 0.01
mol/L) and 10 mL buffer solution
(c(NH
3
/NH
4
NO
3
) = 1 mol/L; pH = 9.6) and ti-
trate.
Remarks:
Select the appropriate formula. The other may
be deleted.
Reference:
Metrohm Application Bulletin Nr. 143
– EDTA content in %
– NTA content in %
– Sample size in g
– Volume of standard solution added
– Factor for %
– Molar mass of EDTA*concentration of titrant
– Molar mass of NTA*concentration of titrant
'pa
794 Titrino 01102 794.0010
date 2002-01-03 time 09:53 0
DET U EDTA-NTA
parameters
>titration parameters
meas.pt.density 4
min.incr. 10.0 µl
titr.rate max. ml/min
signal drift 50 mV/min
equilibr.time 26 s
start V: OFF
pause 0 s
meas.input: 1
temperature 25.0 °C
>stop conditions
stop V: abs.
stop V 4 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: all
activate pulse: OFF
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'fm
794 Titrino 01102 794.0010
date 2002-01-03 time 09:53 0
DET U EDTA-NTA
>calculations
EDTA=(EP1-C01)*C02*C03/C00;2;%
NTA=(EP1-C01)*C02*C04/C00;2;%
C00= 1.0
C01= 2
C02= 100
C03= 2.9225
C04= 1.9114
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