Metrohm 794 Basic Titrino - Manual (Page 179)

6.3 User methods
794 Basic Titrino
175
6.3.11 "Metals"
The following metals can be detected according to this method:
buffer solution molar mass
Barium Ba pH = 10 137.36
Cadmium Cd pH = 10 112.41
Cobalt Co pH = 10 58.94
Lead Pb pH = 4.7 207.21
Nickel Ni pH = 10 58.71
Water, total hardness (Ca+Mg) pH = 10 64.40
Zinc Zn pH = 10 65.38
Electrode:
6.0502.140 Cu electrode and 6.0726.100
Ag/AgCl reference electrode (outer electrolyte
KNO
3
sat.), at measuring input 1.
Titrant:
EDTA, c = 0.1 mol/L
Buffer pH = 10:
54 g NH
4
Cl and 350 mL w(NH
3
) = 0.25 are
dissolved in 1 L dist. water.
Buffer pH = 4.7:
123 g Naac and 86 mL glacial acetic acid are
dissolved in 1 L dist. water.
Sample:
Add 5 mL of buffer solution and 1 mL
c(CuEDTA) = 0.05 mol/L to sample. Wait for
20 – 30 s and titrate.
Remarks:
Refer to the table above for the molar mass of
a metal and the appropriate buffer.
Reference:
Metrohm Application Bulletin Nr. 101
– Content of metal in g/L
– Sample size in mL
– Concentration of titrant
– Molar mass of metal
'pa
794 Titrino 01102 794.0010
date 2002-01-03 time 09:54 0
DET U Metals
parameters
>titration parameters
meas.pt.density 2
min.incr. 10.0 µl
titr.rate max. ml/min
signal drift 20 mV/min
equilibr.time 38 s
start V: OFF
pause 0 s
meas.input: 1
temperature 25.0 °C
>stop conditions
stop V: abs.
stop V 10 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
------------
'fm
794 Titrino 01102 794.0010
date 2002-01-03 time 09:55 0
DET U Metals
>calculations
Content=EP1*C01*C02/C00;2;g/l
C00= 1.0
C01= 0.1
C02= 1
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