Analisis logam dg alat Titrino / Titroprocessor

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0502.140 Cu2+ sensitive indicator electrode; input 1
6.0726.100 Ag/AgCl double junction reference electrode (KNO3 sat.)

Reagents
c(Na2EDTA) = 0.1 mol/L; D0

Sample
2 mL c(ZnSO4) = 0.1 mol/L
5 mL buffer pH = 10
1 mL c(CuEDTA) = 0.1 mol/L
40 mL dist. Water

Remarks
· Calculations:

Content=EP1*C01*C02/C00;2;g/l

Content = content of metal in g/L
C01 = concentration of titrating agent (0.1 mol/L)
C02 = molecular mass of metal (65.38 g/mol)

. Answer

Content=2.006x0.1x65.38/2=6.56 g/L

EP1=2.006 mL
C00=2.000 mL

· Buffer pH = 10:
Dissolve 54 g NH4Cl and 350 mL w(NH3) = 0.25 (25%) in dist. water and fill up to 1 litre.
· Buffer pH = 4.7:
Dissolve 123 g Na-acetate and 86 mL acetic acid in dist. water and fill up to 1 liter.
· The following metals can be determined according to this method:
buffer solution molar mass
Water, total hardness (Ca + Mg) pH = 10… 64.40
Barium Ba pH = 10… 137.36
Cadmium Cd pH = 10… 112.41
Cobalt Co pH = 10… 58.94
Nickel Ni pH = 10… 58.71
Zinc Zn pH = 10…65.38
Lead Pb pH = 4.7…207.21

Literature
· Metrohm Application Bulletin No. 101: Complexometric titrations with the Cu ISE