Penentuan secara Potentiometric Angka Epoxy

Peralatan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0430.100 Ag Titrode; input 1

Pereaksi
c(HClO4) = 0.1 mol/L; D0

Sample
app. 0.2 g UHU resin
25 mL c(TBA) = 0.2 mol/L in acetic acid
TBA = Tetrabutyl ammonium bromide

Remarks
Determination reaction:
O OH
R-CH-CH-R’ + H+ → [R-CH-CH-R’]+
OH OH
[R-CH-CH-R’]+ + Br - → R-CH-CH-R’
Br
Calculations:

Epoxy.No=EP1*C01*C02*C03/C00;3;

Epoxy.No = epoxy number, number of epoxide groups per 100 g of sample
C01 = factor for conversion mL L (0.001)
C02 = concentration of titrating agent (0.1 mol/L)
C03 = factor for 100 g of sample (1000)
Stir sample in solvent during 3 minutes before titration


Answer

Epoxy.No = 8.828 x 0.001 x 0.1 x 1000 / 0.2261 = 0.390

EP1 = 8.828 mL
C00 = 0.2261 g

Literature
I. Gyenes, “Titrationen in nichtwässrigen Medien“
Ferdinand Enke Verlag, Stuttgart (1970), p. 598

Penentuan secara Potentiometric of Pure Silver Content

Peralatan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0404.100 combined massive Ag electrode with AgBr coating; input 1

Pereaksi
c(KBr) = 0.1 mol/L; D0

Sample
app. 250 mg Ag
10 mL HNO3 65 %
100 mL dist. water

Remarks
Calculations:

Silver=EP1*C01*C02*C03*C04/C00;3;%

Silver = content of silver in % ( purity )
C01 = concentration of titrating agent (0.1 mol/L)
C02 = titer (1.0)
C03 = molecular mass of Ag (107.87 g/mol)
C04 = factor for % (100)

Answer

Silver = 22.332 x 0.1 x 1.0 x 107.87 x 100 / 257.7 =93.479 %

EP1 = 22.332 mL
C00 = 257.7 mg

Sample preparation:
Heat silver in HNO3. Allow nitrous fumes to evaporate.

AgBr coating of electrode:
Clean Ag electrode with scouring agent and electrolyse in (HBr) = 0.1 (10%) during 2 h with 5 mA using a 6.0305.000 Pt lectrode as cathode. Stir during electrolysis.

Literature
Metrohm Application Bulletin No. 61: Potentiometric determination of silver.

Penentuan secara Potentiometric dari Perborates didalam Detergents

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0420.100 LL combined Pt electrode; input 1

Reagents
c(KMnO4) = 0.02 mol/L; D0

Sample
5 mL sample solution
20 mL w(H2SO4) = 0.30 (30%)

Remarks
Determination reaction:

5 NaBO₂*H₂O₂ + 2 MnO₄^- + 6 H⁺ → 2 Mn²⁺ + 5 O₂ + 8 H₂O + 5NaBO₂

Calculations:

Perborat=EP1*C01*C02*C03*C04*C05/C00;2;%

Perborat = fraction of perborates in %
C01 = concentration of titrating agent (0.02 mol/L)
C02 = factor for “normality“ (5/2=2.5)
C03 = molecular mass of NaBO2*H2O2*3H2O (153.86 g/mol)
C04 = conversion mL L * factor for % (0.001*100 = 0.1)
C05 = factor for dilution (20)

Answer

Perborat = 1.289 x 0.02 x 2.5 x 153.86 x 0.1 x 20 / 2.5023 = 7.93 %

EP1 = 1.289 mL
C00 = 2.5023 g

Sample preparation:
Weigh 2.5 g in a measuring flask of 100 mL. Dissolve sample with c(H2SO4) = 1 mol/L and wait for the reaction of the carbonate. When gas evolution has stopped, fill measuring flask to the mark. Pipette 5 mL of solution, add 20 mL of w(H2SO4) = 0.30 (30%) and titrate. The 6.0431.100 Pt Titrode may be used instead of the 6.0420.100 LL Pt electrode.

Literature
G. Jander, K.F.Jahr, “Massanalyse“, Sammlung Gröschen de Gruyter, Berlin, New York (1973), p. 67

Penentuan secara potensiometrik Anionic Surfactants in Shampoo, Titrino / Titroprocessor

Peralatan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0507.120 Ionic surfactant electrode; input 1
6.0733.100 Ag/AgCl reference electrode (c(KCl) = 3 mol/L)

Peralatan
c(TEGOtrant A100) = 0.004 mol/L; D0
1,3-didecyl-2-methyl-imidazolium chloride (DDMICl)
Metrohm 6.2317.000

Sample
app. 0.2 g sample (shampoo)
5 mL Methanol puriss p.a.
10 mL Buffer solution pH = 3.0, citrate/HCl, e.g. Merck Tirisol No. 9883
60 mL dist. water

Remarks
Calculations:

Anionic=EP1*C01/C00;4;meq/g

Anionic = concentration of anionic Tensides in meq/g
C01 = concentration of titrating agent (0.004 mol/L)

Answer

Anionic = 12.638 x 0.004 / 0.2128 = 0.2376 meq / g

EP1 = 12.638 mL
C00 = 0.2128 g

Electrode preparation, maintenance and storage:
Store the Ionic Surfactant electrode dry. They are conditioned by two to three titrations. Rinse the electrode after several titrations with methanol or wipe it with a cloth moistend woth methanol and rinse with dist. water. If you use the electrode frequently, it may also be stored in a solution of 1% polyethyleneglycol 1000. In this case, the electrode is always ready to use.

Sample preparation:
Adjust the sample size in order to have a titrating agent consumption of at least 10 mL. The pH of buffer solution, the amount of added methanol may change according to the type of surfactant. See also Application Bulletin No. 233.

Literature
Metrohm Application Bulletin No. 233: Titrimetric / potentiometric determination of anionic and cationic detergents with the high-sense surfactant electrode.

Penentuan secara potensiometrik Cationic Surfactants in Fabric Softener, Titrino / Titroprocessor

Peralatan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0507.120 Ionic surfactant electrode; input 1
6.0733.100 Ag/AgCl reference electrode (c(KCl) = 3 mol/L)

Pereaksi
c(DOS) = 0.01 mol/L; D0
Dioctylsodium sulfosuccinat M(DOS) = 444.57 g/mol, Fluka No. 86139

Sample
app. 1 g sample (fabric softener)
5 mL Methanol puriss p.a.
5 mL Buffer solution pH = 3, citrate/HCl, e.g. Merck Titrisol No. 9883
1 mL c(HCl) = 2 mol/L
60 mL dist. water

Remarks
Calculations:

Cationic=EP1*C01/C00;4;meq/g

Cationic = concentration of cationic surfactants in meq/g
C01 = concentration of titrating agent (0.01 mol/L)

Answer

Cationic = 12.631 x 0.01 / 1.0631 = 0.1188 meq/g

EP1 = 12.631 mL
C00 = 1.0631 g

Electrode preparation, maintenance and storage:
Store the Ionic Surfactant electrode dry. They are conditioned by two to three titrations. Rinse the electrode after several titrations with methanol or wipe it with a cloth moistend woth methanol and rinse with dist. water. If you use the electrode frequently, it may also be stored in a solution of 1% polyethyleneglycol 1000. In this case, the electrode is always ready to use.

Sample preparation:
Adjust the sample size in order to have a titrating agent consumption of at least 10 mL.
The pH of buffer solution, the amount of added methanol or the titrating agent may change according to the type of surfactant. See also Application Bulletin No. 233.

Literature
Metrohm Application Bulletin No. 233: Titrimetric / potentiometric determination of anionic and cationic detergents with the high-sense
surfactant electrode.

Penentuan Non-ionic Surfactants dengan NIO Electrode, Titrino / Titroprocessor

Peralatan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0507.010 NIO surfactant electrode; input 1
6.0726.100 Ag/AgCl double junction reference electrode
(inner electrolyte c(KCl) = 3 mol/L, outer electrolyte
c(NaCl) = 1 mol/L)

Pereaksi
c(STPB) = 0.01 mol/L; D0
STPB = sodium tetraphenylborate

Sample
5 mL sample solution
3 mL c(BaCl2) = 0.1 mol/L
60 mL dist. water

Remarks
Titrating agent:

Dissolve 3.4223 g sodium tetraphenylborate in 300 mL dist. water. Dissolve separately 10 g polyvinyl alcohol in 300 mL dist. water and heat it slightly. Allow to cool and rinse both solutions in a 1000 mL flask. Add 10 mL buffer pH = 10 and fill up to 1 liter.

BaCl2 solution:
Dissolve 21 g BaCl2 or 25 g BaCl2*2H2O in dist. water, add 1 mL
conc. HCl and fill up to 1 liter.

Buffer pH = 10:
Dissolve 1.24 g H3BO4 in dist. water, add 10 mL c(NaOH) = 1 mol/L and fill up to 100 mL.

Sample preparation:

Dissolve app. 0.5 ... 1 g detergent (Renex 650 ICI; polyoxyethylene-(30)-nonylphenol, molecular mass 1541 g/mol) in 100 mL dist. water.

Calculations:

Nonionic=EP1*C01*C02/C00;4;meq/g

Nonionic = concentration of nonionic Tensides in meq/g
C01 = concentration of titrating agent (0.01 mol/L)
C02 = dilution factor for the sample solution, aliquot (20)

Nonionic = 8.795 x 0.01 x 20 / 0.5145 = 3.4189 meq/g

EP1 = 8.795 mL
C00 = 0.5145 g

Literature
Metrohm Application Bulletin No. 230: Titrimetric/potentiometric determination of non-ionic tensides (oxyethylates) with the NIO electrode

PENENTUAN SECARA POTENSIOMETRK EDTA / NTA DALAM DETERGEN DG ALAT TITRINO / TITROPROCESSOR

Peralatan
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.)

Pereaksi
c(Cu²⁺) = 0.01 mol/L; D0

Sample
10 mL sample solution
10 mL buffer pH = 9.6 [c(NH₃/NH₄NO₃) = 1 mol/L]
2 mL c(Na₂EDTA) = 0.01 mol/L
30 mL dist. Water

Remarks
Perhitungan:

EDTA=(EP1-C01)*C02*C03/C00;2;%
NTA=(EP1-C01)*C02*C04/C00;2;%

EDTA = content of EDTA in %
NTA = content of NTA in %
C01 = amount of EDTA/NTA added (2 mL)
C02 = factor for % (100)
C03 = 1 mL c(Cu²⁺) = 0.01 mol/L = 2.9225 mg EDTA
C04 = 1 mL c(Cu²⁺) = 0.01 mol/L = 1.9114 mg NTA

Answer

EDTA = (3.004-2.00) x 100 x 2.9225 / 82.63 = 3.55 %
NTA = (3.004-2.00) x 100 x 1.9114 / 82.63 = 2.32 %

EP1 = 3.004 mL
C00 = 82.63 mg

Sample preparation:

Dissolve 0.5 ... 1 g detergent in 50 mL dist. water at 40 °C. Allow solution to cool and add up to 100 mL. Select the appropriate formula. The other may be deleted. Na2EDTA is added to get a greater break. Treat the amount of Na2EDTA added like a blank value.

Literature
Metrohm Application Bulletin No. 143: Potentiometric determination of nitrilotriacetic acid (NTA) and/or ethylenediaminetetracetic acid (EDTA) in detergents.

PENENTUAN SECARA POTENSIOMETRIK 2-AMINOPHENOL DG ALAT TITRINO / TITROPROCESSOR

Peralatan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0431.100 Pt Titrode; input 1

Pereaksi
c(NaNO₂) = 0.2 mol/L; D0

Sample
app. 0.3 ... 0.35 g sample (2-aminophenol)
10 mL w(HBr) = 0.20 (20%)
30 mL dist. Water

Remarks
Determination reaction:

H+

R-NH₂ + HNO₂ + HBr →[R-NN+]Br- + 2 H₂O

Perhitungan:

Content=EP1*C01*C02*C03/C00;2;%

Content = content of 2-aminophenol in %
C01 = molecular mass of 2-aminophenol (109.13 g/mol)
C02 = factor for conversion mL to L, and for % (0.001*100=0.1)
C03 = concentration of titrating agent (0.2 mol/L)
Enter the appropriate molecular mass for other amines (C01).
Instead of the Pt Titrode the 6.0420.100 combined Pt electrode can be used.

. Answer

Content = 14.396 x 109.13 x 0.1 x 0.2 / 0.3188 = 98.56 %

EP1 = 14.396 mL
C00 = 0.3188 g

Literature

Metrohm Application Bulletin No. 228: Diazotisation titrations

PENENTUAN LIPASE DENGAN ALAT TITRINO / TITROPROCESSOR

Peralatan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0233.100 combined pH glass electrode; input 1
6.1110.100 T sensor

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

Sample
29.5 mL substrate emulsion
0.5 mL enzyme solution

Remarks
Pancreas lipase is determined using a TIP method: The pH is adjusted to 9.20 with a pretitration (LipPre), then the sample is addedand the pH kept at 9 during 5 minutes (LipDeter). The determination is carried out in a thermostated titration vessel (e.g. 6.1418.220) at 37 °C.

Perhitungan:

FIP=C70*C31/C00;1;U/mg

LipStd
Factor = calculation factor
FIP = activity of the reference standard in FIP units/mg.
C01 = declared activity of FIP standard (36.2)
C02 = 1000*concentration of titrating agent (100)
C70 = mean rate from LipDeter
LipSmpl1)
FIP = activity of the sample in FIP units/mg.
C30 = calculation factor from LipStd
C70 = mean rate from LipDeter
LipSmpSC2)
FIP = Aativity of the sample in FIP units/mg.
C31 = calculation factor from silo calculation of LipStd
C70 = mean rate from LipDeter
1): Delete the following assignments in method „LipStd“:
. in key , >silo calculations, C24=RS1 and C25=RS2
. in key , >common variables, C31=C26
2): Delete the following assignment in method „LipStd“:
. in key , >common variables, C30=MN1

Solution of Arabic gum:
Dissolve 100 g Arabic gum in 1000 mL dist. water. Centrifuge until the solution is clear (app. 10 minutes with 4000 r/min). This solution can be kept several weeks if frozen in portions.

Substrate standard solution:
Add 165 mL Arabic gum solution, 20 mL olive oil (BP 73) and 15 mLdist. water and cool it in ice to 5 °C. Homogenize with an electric mixer during 30 minutes. The temperature of the solution should never rise above 30 °C. This solution can be kept up to 14 days in a refrigerator. Always homogenize the emulsion before use.

Substrate emulsion:

Stir 100 mL substrate standard solution, 80 mL TRIS buffer solution, 20 mL sodium taurocholate and 95 mL dist. water. This solution must be prepared daily.

TRIS buffer solution:
Dissolve 60.6 mg Tris(hydroxymethyl)-amino methane (C4H11NO3) and 234.0 mg sodium chloride in dist. water and fill up to 100 mL. This solution can be kept up to 3 days in a refrigerator.

Sodium taurocholate solution:
Dissolve 4.0 g sodium taurocholate (F.I.P. controlled) in dist. Water and fill up to 50 mL.

Enzyme solvent

Dissolve 10.0 g sodium chloride, 6.06 g Tris(hydroxymethyl)-amino methane and maleic acid anhydride (C4H2O3) in 900 mL dist. water. Adjust pH to 7.0 with 4N NaOH (app. 13 mL) and fill up to 1000 mL. This solution can be kept up to 3 days in a refrigerator.

Sample preparation:
Dissolve the enzyme in the enzyme solvent. The solution should contain between 8 and 16 FIP Units per mL.

Comments to parameters:

LipDeter Time windows for rate evaluation. Monitoring of rate and temperature is ON: the rate should be kept in the range of 0.08...0.16 mL/min, the temperature in 0.1°C. LipStd, LipSmpl, LipSmpSC T may be measured with .

Literature

B. Stellmach, Bestimmungsmethoden Enzyme, Steinkopff Verlag Darmstadt, 1988, p. 263

PENENTUAN TRYPSIN DG TITRINO / TITROPROCESSOR

Peralatan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0234.100 combined micro pH glass electrode; input 1
6.1110.100 T sensor

Pereaksi

c(NaOH) = 0.1 mol/L in a 1 mL exchange unit; D0

Sample
10 mL borate buffer solution pH = 8.0
1 mL substrate solution
0.05 mL enzyme solution

Remarks

Trypsin is an enzyme which is determined using a TIP method: The pH is adjusted to 8.00 with a pretitration (TrypsPre), then the sample is added and the pH kept at 8 during 8 minutes (TrypsDet). The determination is carried out in a thermostated titration vessel (e.g.6.9914.023 with 6.2036.000 holding ring) at 25 °C.

Perhitungan:

FIP = calculation using the final volume, according to FIP. Result in FIP units/mg.
FIP(reg) = calculation using the mean rate. Result in FIP units/mg. *)
C01 = (factor for mLL) * (concentration of reagent)(100)
C02 = determination time = 8 minutes
C70 = final volume from TrypsDet
C71 = mean rate from TrypsDet

*) The calculation using the mean rate is fundamentally different form the FIP method (final volume / time). The mean rate is calculated by linear regression over all measuring points of the list. If you wish to use only the linear part of the curve for the regression, use a start time of app. 30 s in the method “TrypsDet“. If one of the formulas is not used, you may delete it.

Sample preparation:

Dissolve the enzyme in c(HCl) = 0.001 mol/L. The solution should not contain more than 50 FIP Units per mL.

Substrate solution:

Dissolve 171.3 mg N-Benzoyl-L-arginine ethylester hydrochloride in dist. water and fill up to 25 mL.

Borate buffer solution pH = 8.00:
Dissolve 286.0 mg Disodiumtetraborate-decahydrate and 1.47 g Calciumchloride-dihydrate in 400 mL dist. water, set the pH with c(HCl) = 1 mol/L to 8.00 and fill up with dist. water to 500 mL.

Comments to parameters:

TrypsDetMonitoring of pH and temperature is ON: pH should be kept in the range of 0.1, the temperature in 0.1°C. Trypsin T may be measured with .


Literature
B. Stellmach, Bestimmungsmethoden Enzyme, Steinkopff Verlag Darmstadt, 1988, p. 263

Penentuan Antacid dlm tablet

Peralatan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0233.100 combined pH glass electrode; input 1
6.1110.100 T sensor

Pereaksi
c(HCl) = 1.0 mol/L; D0

Sample
25 mL dist. water
1 drop c(NaOH) = 0.1 mol/L
0.268 g Antacid Trigastril (or 0.2-0.4 g)

Remarks
Method to determine the efficiency of tablets against an excess of acid in the stomach. Use a TIP method for the determination: The pH is adjusted to 3 with a pretitration (AntacPre), then the sample is added and the pH kept at 3 during 30 minutes (AntacDet). The determination is carried out in a thermostated titration vessel (e.g.6.1418.220) at 37 °C. You may have to adjust the control parameters of the submethod “AntacDet“ according to your sample. The given parameters are optimized for products which release their base slowly (rate app. 100 L/min).

perhitungan:

Acid cap=C70*C01/C00;3;mmol/g

acid cap = acid capacity in mmol/g
C01 = concentration of titrating agent (1 mol/L)

Jawaban

Acid cap = 3.218 x 1 /0.268 = 12.008 mmol/g

C00= 0.268
C01= 1
C70= 3.218

Sample preparation:
Pulverize the tablet and weigh it exactly. Rinse the powder with 20 mL of pretitrated solution (pH=3) into the titration vessel during the request “Add smpl & start“ and titrate immediately.

Literature
N.J. Kerkhoff et al., Journal of Pharmaceutical Sciences, 66, 1528-1535 (1977)

Penentuan Na+ / Cl- dalam lart Isotonik dg alat titrino/titroprocessor

Peralatan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0430.100 Ag Titrode; input 1

Pereaksi
c(AgNO3) = 0.1 mol/L; D0

Sample
5 mL sample solution (153 mmol/L Na+ / Cl-)
2 mL c(HNO3) = 2 mol/L
30 mL dist. water

Remarks
· Perhitungan:

Na+Cl-=EP1*C01*C02/C00;2;mmol/l

Na+Cl- = concentration of Na+ / Cl- in isotonic solution in mmol/L
C01 = concentration of titrating agent (0.1 mol/L)
C02 = factor for conversion mol/L Þ mmol/L (1000)

. Jawaban

Na+Cl- = 7.652 x 0.1 x 1000 / 5.00 = 153.04 mmol/L

EP1 = 7.652 ml
C00 = 5 mL

Literature
· Metrohm Application Bulletin No. 130: Chloride titrations with
potentiometric end-point indication.

Penentuan vitamin C dg alat Titrino / Titroprocessor

Peralatan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0309.100 double Pt sheet electrode; input Pol
polarized Ipol = 1 mA
Voltametric indication

Pereaksi
c(DPIP) = 0.001 mol/L; D0
2,6-Dichlorophenol indophenol

Sample
5 mL sample solution
Dissolve 1 effervescent vitamin C tablet in 1 L dist. water
15 mL oxalic acid solution 1 g/L
1 mL w(sodium acetate) = 0.10 (10%)
10 mL dist. Water

Remarks
· Perhitungan:

Vit.C=EP1*C01*C02*C03;0;mg/pc
Vit.C=EP1*C01*C02/C00;4;g/l

Vit.C = content of Vitamin C in mg/pc (tablet)
Vit.C = content of Vitamin C in g/L
C01 = mg Vitamin C / 1 mL titrating agent (0.088)
C02 = factor of titrating agent (1.00)
C03 = dilution factor (200)

. Jawaban

Vit.C = 15.291 x 0.088 x 1.00 x 200 = 269 mg/pc
Vit.C = 15.291 x 0.088 x 1.00 / 5.00 = 0.2691 g/L

EP1 = 15.291 mL
C00 = 5.00 mL

· Titrating agent:
Dissolve 295 mg 2,6-Dichlorophenol indophenol with vigorous agitation in 1 L dist. water, then filter and mix with 100 mg sodium bicarbonate.
This solution can be stored in the refrigerator for about 1 month, the factor should be checked daily with standard ascorbic acid. (As a titrating agent, the more readily soluble sodium salt may be used instead.)

· Standard solution:
r (Vitamin C) = 500 mg/L
Dissolve 50 mg ascorbic acid in oxalic acid solution (1 g/L) and make up to 100 mL. This solution should be freshly prepared daily.

· Sample preparation:
Place dist. water, oxalic acid solution and sodium acetate buffer in the titration vessel and deaerate by passing a stream of nitrogen for 3...5 min. Then add a quantity of sample or standard solution containing about 0.05...0.5 mg vitamin C. Now titrate under nitrogen with titrating agent.
· Store electrode in acidified Na2S2O3 solution.
· Select the appropriate formula. The other may be deleted.
· The 6.0431.100 Pt Titrode may be used together with mode MET U.

Literature
· Metrohm Application Bulletin No. 98: Determination of ascorbic acid
(Vitamin C) and its compounds.

Penentuan angka iodium dg alat Titrino / Titroprocessor

Peralatan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0431.100 Pt Titrode; input 1

Pereaksi
c(Na2S2O3) = 0.1 mol/L; D0

Sample
app. 0.5 g sunflower oil
15 mL CCl4
25 mL c(ICl) = 0.1 mol/L (according to Wijs in glacial acetic acid / CCl4,
e.g. Merck No. 9163)
10 mL w(Hg acetate) = 0.025 (2.5%) in glacial acetic acid
15 mL w(KI) = 0.10 (10%)
30-50 mL dist. water

Remarks
· Perhitungan:

Iod.No=(C01-EP1)*C02/C00;2;g/100g

Iod.No = iodine number in g iodine / 100 g sample
C01 = consumption of blank sample (0 mL)
C02 = molecular mass of I * concentration titrating agent * 100g
sample / factor mL -> L (126.9 * 0.1 *100/1000 = 1.269)

. Jawaban

Iod.No = (0 – 6.149) x 1.269 / 0.5204 = 104.61 g/100g

EP1 = 6.149 mL
C00 = 0.5204 g

· Sample preparation:
According to the expected iodine number, weigh out 0.10 ... 1.00 g of the sample in an Erlenmeyer flask and add 15 mL CCl4.
Add 25 mLiodine monochloride solution and add 10 mL mercuric acetate solution, mix and allow to stand for 5 min. in a dark place.
Then add 15 mL KI solution, rinse into a beaker with dist. water and back-titrate the excess iodine with sodium thiosulphate.
A blank control sample should be prepared and treated in the same way. Enter the blank value as C01.
· You may add a solution of w(Mg-acetate) = 0.03 (3%) instead of the Hg-acetate solution.
· The sample must be stirred well during the titration, in order to obtain a good emulsion.

Literature
· Metrohm Application Bulletin No. 141: Analysis of edible oils and fats.

Penentuan angka asam dg alat Titrino / titroprocessor

Peralatan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0133.100 pH glass electrode; input 1
6.0726.100 Ag/AgCl double junction reference electrode
(LiCl sat. in ethanol)

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

Sample
app. 5-10 g sunflower oil
50 mL ethanol / diethylether (1 : 1), neutralized

Remarks
· Calculations:

Acid.No=EP1*C01/C00;2;mg/g
FFA=RS1*C02/C03;2;

Acid.No = acid number in mg KOH per g of sample
FFA = free fatty acid
C01 = mg KOH / 1 mL titrating agent (5.61)
C02 = relative molecular mass (282 for oleic acid)
C03 = factor (561)

. Jawaban

Acid.No = 0.150 x 5.61 / 10.3223 = 0.08 mg/g
FFA = 0.08 x 282 / 561 = 0.04

RS1 = 0.08
EP1 = 0.150 mL
C00 = 10.3223 g

Literature
· Metrohm Application Bulletin No. 141: Analysis of edible oils and fats.

Penentuan angka saponifikasi (Saponification Number) dg alat titrino/titroprocessor

Peralatan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0232.100 combined pH glass electrode; input 1

Pereaksi
c(HCl) = 1 mol/L; D0

Sample
app. 2 g sunflower oil
25 mL c(KOH) = 0.5 mol/L in ethanol
app. 10-20 mL dist. water

Remarks
· Calculations:

Sapon.No=(C01-EP1)*C02/C00;1;mg/g

Sapon.No = saponification number in mg KOH per g of sample
C01 = consumption of blank sample (12.199 mL)
C02 = mg KOH / 1 mL titrating agent (56.1)

. Answer

Sapon.No = (12.199-5.271) x 56.1 / 2.0224 = 192.2 mg/g

EP1 = 5.271 mL
C00 = 2.0224 g

· Sample preparation:
Weigh out approx. 2 g sample in a round-bottomed flask. Add 25 mL alcoholic KOH solution plus a few boiling beads and allow to boil lightly for at least 30 min. Shake from time to time. Finally rinse the content of the round-bottomed flask into a beaker with a small quantity of dist. water and back titrate the excess of potassium hydroxide with HCl. A blank control sample should be prepared and
treated identically. Enter the blank value as C01.

Literature
· Metrohm Application Bulletin No. 141: Analysis of edible oils and fats.

Penentuan angka peroksida dg alat titrino/titroprocessor

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0431.100 Pt Titrode; input 1

Reagents
c(Na2S2O3) = 0.01 mol/L; D0
Prepared daily from c = 0.1 mol/L

Sample
app. 5 g sunflower oil
50 mL glacial acetic acid / chloroform (3 : 2)
1 mL KI saturate
100 mL dist. water

Remarks
· Calculations:

Perox.No=(EP1-C01)*C02/C00;2;meq/kg

Perox.No = peroxide number in meq.O2/kg
C01 = consumption of blank sample (0 mL)
C02 = factor (10)

. Answer

Perox.No = 0.8874 x 10 / 5.0188 = 1.77 meq/Kg

EP1 = 0.8874 mL
C00 = 5.0188 g

· Sample preparation:

Weigh out accurately 5 g sample in an Erlenmeyer flask and add 50 mL of the glacial acetic acid / chloroform mixture. Then add 1 mL of the KI solution and shake during 5 s. Now allow the mixture to stand for about 1 min. in a dark place. After this, rinse the contents of the Erlenmeyer flask out into a beaker with 100 mL dist. water and immediately back-titrate the iodine thus liberated with sodium
thiosulphate. A blank control sample should be prepared and treated in the same way. Enter the blank value as C01. The sample must be stirred well during the titration, in order to obtain
a good emulsion.

Literature
· Metrohm Application Bulletin No. 141: Analysis of edible oils and fats.

Analisis NaCl dlm kaldu dg, Titrino/Titroprocessor

Alat yg digunakan

Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0430.100 Ag Titrode amalgamated; input 1

Pereaksi
c(AgNO3) = 0.1 mol/L; D0

Sample
20 mL sample solution
5 mL c(HNO3) = 2 mol/L
30 mL dist. Water

Remarks
· Calculations:

NaCl=EP1*C01*C02*C03/C00;2;%

NaCl = content of NaCl in broth in %
C00 = sample size (10 g / 100 = 0.1 g)
C01 = molecular mass of NaCl (58.44 g/mol)
C02 = concentration of titrating agent (0.1 mol/L)
C03 = factor for conversion mL Þ L and for % (0.001*100 = 0.1)

. Answer

NaCl = 8.070 x 58.44 x 0.1 x 0.1 / 0.1 = 47.16 %

EP1 = 8.070 mL
C00 = 0.1 g

· Sample preparation:
Dissolve 10 g (1 cube) conc. broth in 800 mL boiling dist. water. Rinse
this solution in a 2000 mL measuring flask. Allow to cool down and fill
up to the mark. Filter with a folded filter. Take 20 mL aliquots.

Literature
· Metrohm Application Bulletin No. 130: Chloride titrations with
potentiometric end-point indication.

Analisis angka asam (total acid number) dg potensiometer , Titrino/titroprocessor

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0133.100 pH glass electrode; input 1
6.0729.100 Ag/AgCl reference electrode ( LiCl sat in ethanol); input 2
6.0331.000 Pt auxiliary electrode; input Ref.
Differential potentiometry

Pereaksi
c(TBAOH) = 0.1 mol/L in isopropanol/methanol; D0
TBAOH = Tetrabutyl ammonium hydroxide

Sampel
app. 1.5 g of used motor oil
50 mL solvent: chlorobenzene : isopropanol (2 : 1)

Remarks
· Calculations:

TAN=(EP1-C01)*C02*C03/C00;2;mg/g

TAN = acid of sample, calculated as mg KOH per g of sample
C01 = blank value, consumption of titrating agent by solvent mixture (0 mL)
C02 = concentration of titrating agent (0.1 mol/L)
C03 = molecular mass of KOH (56.106 g/mol)

. Answer

TAN = (0.680) x 0.1 x 56.106 / 1.6646 = 2.29 mg/g

EP1 = 0.680 mL
C00 = 1.6646 g

· Store glass electrode in dist. water over night. Before titrating,
precondition it in solvent during 10 - 30 min.
· The 6.0430.100 Ag Titrode may be used instead of the 6.0133.100
and 6.0331.000 electrodes. In this case, you make differential
potentiometry with only two electrodes, the Ag Titrode and the
6.0729.100 reference electrode.

Literature

· Metrohm Application Bulletin No. 80: Determination of the acid / base
number in petroleum products (TAN/TBN)
· ASTM D 2896 - 80
· DIN 51596

Determination of Oxidizability of Waste Water with Potentiometric Method

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0431.100 Pt Titrode; input 1

Reagents
c(1/5KMnO4) = 0.01 mol/L; D0

Sample
25 mL waste water
5 mL w(H2SO4) = 0.35 (35%)
75 mL dist. water
15 mL c(1/5KMnO4) = 0.01 mol/L
15 mL c(1/2Oxalic acid) = 0.01 mol/L

Remarks
· Prepare sample as follows:
Add 75 mL dist. water and 5 mL w(H2SO4) = 0.35 (35%) to 25 mL of sample and heat up to a boiling mixture.

Add 15.00 mL of c(1/5KMnO4) = 0.01 mol/L and keep boiling for 10 minutes. Then add 15 mL c(1/2Oxalic acid) =0.01 mol/L.
Titrate with c(1/5KMnO4) = 0.01 mol/L according to parameters.

· Calculations:

Oxidiza.=EP1*C01*C02/C00;3;mg/L

Oxidiza. = oxidizability in mg/L permanganate consumption
C01 = molecular mass of KMnO4 * concentration of titrating agent / normality (158 * 0.01 / 5 = 0.316 g/L)
C02 = conversion g Þ mg for result expression in mg/L KMnO4 (1000)

. Answer

Oxidiza = 3.682 x 0.316 x 1000 / 25 = 46.540 mg/L

Literature
· Deutsche Einheitsverfahren zur Wasseruntersuchung Kapitel H4, Abschnitt 1

Penentuan kesadahan total dg alat potensiometer, Titrino / Titroprocessor with Potentiometric Method

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0239.100 combined pH glass electrode; input 2
6.0504.100 Ca2+ sensitive indicator electrode; input 1 reference system used from 6.0239.100

Pereaksi

c(Na2EDTA) = 0.05 mol/L in c(KOH) = 0.1 mol/L; D0
c(HCl) = 0.1 mol/L; D1
c(Acetylacetone) = 0.1 mol/L in c(Trishydroxy methylaminomethane) = 0.1 mol/L (auxiliary complexing agent, pH app. 8.5); D2

Sample
100 mL water

Remarks
· Method p+m val.
Values for the acid capacity of water.
p value = value of Phenolphthalein
m value = value of Methyl orange
The method can also be used just for p+m values, see Application 2-3.
· Method Ca-Mg:
1st break: Ca2+
2nd break: Mg2+
The method can also be used just for Ca/Mg determinations, see Application 1-7.

· Calculations:

p value=C71;2;mmol/l
m value=C72;2;mmol/l
Ca++=C73*C01*C02/C00;2;mmol/l
Mg++=(C74-C73)*C01*C02/C00;2;mmol/l
Total=C74*C01*C02/C00;2;mmol/l

p value = p value in mmol/L (if 0.00 mmol/L, the water has an initial pH below 8.2)
m value = m value in mmol/L (acid-binding-capability)
Ca++ = calcium hardness in mmol/L
Mg++ = magnesium hardness in mmol/L
Total = total hardness in mmol/L
C01 = concentration of titrating agent (0.05 mol/L)
C02 = factor for conversion for mol Þ mmol (1000)
C70 = initial pH of sample (p+m val.) = 7.75
C71 = EP1 at pH 8.2 (p+m val.) = 0.00
C72 = EP2 at pH 4.3 (p+m val.) = 5.69
C73 = EP1 from Ca2+ (Ca-Mg) = 4.471
C74 = EP2 from Mg2+ (Ca-Mg) = 6.055

. Answer

P value = 0.00 mmol/L
M value = 5.69 mmol/L
Ca++ = 4.471 x 0.05 x 1000 / 100 = 2.24 mmol/L
Mg++ = (6.055-4.471) x 0.05 x 1000 / 100 = 0.79 mmol/L
Total = 6.055 x 0.05 x 1000 / 100 = 3.03 mmol/L


· Electrode preparation:
Ca electrodes should be conditioned for 10 min. in c(CaCl2) = 0.01 mol/L before use.
· The volume of the auxiliary reagent can be optimised for the
magnesium content. Rule of thumb: Ratio Mg/Acetylacetone app. 0.05.


Literature
· Metrohm Application Bulletin No. 125: Complexometric simultaneous determination of calcium and magnesium in water samples and beverages with the aid of an ion-selective calcium electrode

Determination of p and m Value with Potentiometric Method

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0239.100 combined pH glass electrode; input 2

Reagents
c(HCl) = 0.1 mol/L; D1

Sample
100 mL tap water

Remarks
· Values for the acid capacity of water.
p value = value of Phenolphthalein
m value = value of Methyl orange

· Calculations:

p value=EP1*C01;2;mmol/l
m value=EP2*C01;2;mmol/l

p value = p value in mmol/L (if 0.00 mmol/L, the water has an initial pH below 8.2)
m value = m value in mmol/L
C01= titer of titrating agent (1.0)

p value= 0.00 mmol/l
m value=5.653 x1.0 = 5.65 mmol/l

EP1 = 0.00 mL
EP2 = 5.653 mL

· The dosing unit is external D1. This method can therefore be used directly in the TIP „Hardness“ (Application 2-4), an automated water analysis method.
· Calibrate the electrode for the SET titration.
· For automatic curve output add in , >report “curve“.

Literature
· DIN 38 409, Teil 7 (19)

Analisis kloridadlm air dg alat potensiometer, Titrino/Titroprocessor

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0430.100 Ag Titrode amalgamated; input 1

Reagents
c(AgNO3) = 0.01 mol/L; D0

Sample
100 mL tap water
0.5 mL c(HNO3) = 2 mol/L

Remarks
. Calculations:

Chloride=EP1*C01*C02*C03/C00;2;ppm

Chloride = fraction of chloride in ppm
C01 = concentration of titrating agent (0.01 mol/L)
C02 = molecular mass of Cl- (35.45 g/mol)
C03 = factor for ppm (1000)

. Answer

Chloride = 1.533 x 0.01 x 35.45 x 1000 / 100 = 5.43 ppm

EP1 = 1.533 mL
C00 = 100 mL

Literature

Metrohm Application Bulletin No. 130: Chloride titrations with
potentiometric end-point indication.

Analisis asam boraks dg alat potensiometer, titrino / Titroprocessor

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0232.100 combined pH glass electrode; input 1

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

Sample
5.00 mL c(H3BO3) = 0.1 mol/L
10 mL d-mannitol solution, saturated
40 mL dist. Water

Remarks

· Determination reaction:
Boric acid forms an ester with mannitol:
HO-CH HC-O O-CH -
H3BO3 + 2 → B H+ + 3 H2O
HO-CH HC-O O-CH

H3BO3+2H4C2O2 →( H4C4BO4 ) - H ++ 3 H2O

· Calculations:

Bor=EP1*C01*C02*C37/C00;1;mg/l

Bor = content of Bor in mg/L
C01 = bor equivalent (1.081 mg/mL titrating agent)
C02 = factor for the conversion mL Þ L (1000)
C37 = titer of titrating agent (1.0013)
· d-mannitol solution, saturated:
App. 200 g d-mannitol dissolved in dist. water.

. Answer

Bor = 4.719 x 1.081 x 1000 x 1.0013 / 5.0 = 1021.6 mg/L

EP1 = 4.719 mL
C00 = 5.0 mL

Literature
· Metrohm Application Bulletin No. 66: Potentiometric
determination of boric acid.

Analisis Klorida di dlm air dg alat Titrino / Titroprocessor

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0430.100 Ag Titrode; input 1

Reagents
c(AgNO3) = 0.1 mol/L; D0

Sample
5 mL c(NaCl) = 0.1 mol/L
2 mL c(HNO3) = 2 mol/L
40 mL dist. Water

Remarks
· Calculations:

Chloride=EP1*C01*C02*C03/C00;2;%
NaCl=EP1*C01*C04/C00;2;g/l

Chloride = content of chloride in %
NaCl = content of NaCl in g/L
C01 = concentration of titrating agent (0.1 mol/L)
C02 = molecular mass of Cl- (35.45 g/mol)
C03 = factor for % (0.1)
C04 = molecular mass of NaCl (58.44)
· Select the appropriate formula. The other may be deleted. Or change the formula according to your application.

. Answer

Chloride=4.969x0.1x35.45x0.1/5=0.35%
NaCl=4.969x0.1x58.44/5=5.81 g/L

EP1=4.969 mL
C00=5.000 mL

Literature
· Metrohm Application Bulletin No. 130: Chloride titrations with potentiometric end-point indication

Analisis besi (Fe II) dg alat Titrino / Titroprocessor

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0431.100 Pt Titrode; input 1

Pereaksi
c(KMnO4) = 0.02 mol/L; D0
Sample
2 mL c[(NH4)2Fe(SO4)2] = 0.1 mol/L, acidic solution
10 mL c(H2SO4) = 0.5 mol/L
40 mL dist. Water

Rangkuman
· Determination reaction:

5 Fe2+ + MnO4- + 8 H+ → 5 Fe3+ + Mn2+ + 4 H2O

· Calculations:

Fe++=EP1*C01*C02/C00;2;g/l

Fe++ = concentration of Fe2+ in g/L
C01 = concentration of titrating agent * titer * “normality“ (0.02 * 1.000 * 5 = 0.1)
C02 = molecular mass of Iron (55.85 g/mol)

Answer

Fe++=2.065x0.1x55.85/2=5.77 g/L

EP1=2.065 mL
C00=2.000 mL

Literature
Metrohm’s Teachware on CD-ROM

analisis iodium dg alat Titrino / Titroprocessor

Alat yg digunakan
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.)

Pereaksi
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

Rangkuman
· 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

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

Analisis calsium dg alat Titrino / titroprocessor

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0430.100 Ag Titrode amalgamated; input 1

Pereaksi
c(Na2EDTA) = 0.1 mol/L; D0
Sample 2 mL c(CaCl2) = 0.1 mol/L
10 mL buffer pH = 10
40 mL dist. Water

Remarks

· Calculations:

c(Ca++)=EP1*C01/C00;3;mol/l

Ca++ = concentration of Ca2+ in mol/L
C01 = concentration of titrating agent (0.1 mol/L)

. Answer

c(Ca++) = 2.043 x 0.1/2 = 0.102mol/L

EP1=2.043 mL
C00=2.000 mL
· Coating of Ag Titrode: Clean Ag Titrode first by immersing it in conc. HNO3, then immerse it shortly in Hg.
· Buffer pH = 10: Dissolve 54 g NH4Cl and 350 mL w(NH3) = 0.25 (25%) in dist water and fill up of 1 liter. · If several metal ions which form EDTA complexes are present, their sum is determined. · For a greater break, add Hg-EDTA complex.

Literature
Metrohm’s Teachware on CD-ROM

Analisis asam oxalat dlm fasa organik dg alat Titrino / Potensiometri

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0103.100 pH glass electrode; input 1
6.0726.100 Ag/AgCl double junction reference electrode (LiCl sat. in ethanol)

Reagents
c(TBAOH) = 0.1 mol/L; D0
TBAOH = Tetrabutyl ammonium hydroxide

Sample
2 mL c(C2H2O4) = 0.1 mol/L; HOOC-COOH
25 mL ethanol

Remarks
Calculations:

Oxalic=EP2*C01/C02/C00;3;mol/l

Oxalic = concentration of oxalic acid in mol/L
C01 = concentration of titrating agent (0.1 mol/L)
C02 = factor for “normality“ (2) · Compare also titration in aqueous medium, application No. 1-4

Answer

Oxalic = 4.221 x 0.1 / 2 / 2 = 0.106 mol/L

EP1 = 2.048 mL
EP2 = 4.221 mL
C00 = 2.00 mL

Literature
Metrohm’s Teachware on CD-ROM

Analisis asam oxalat dg alat Titrino / Titroprocessor

Alat yang digunakan

Potentiometer = 751 GPD Titrino / Titroprocessor

Electrodes = 6.0232.100 combined pH glass electrode; input 1

Pereaksi

c(NaOH) = 0.1 mol/L; D0

Sampel

2 mL c(C2H2O4) = 0.1 mol/L;

HOOC-COOH pK1 = 1.42, pK2 = 4.31

50 mL dist. water

Rangkuman
Calculations:

Oxalic=EP2*C01*C37/C02/C00;3;mol/L

Oxalic = concentration of oxalic acid in mol/L

C01 = concentration of titrating agent (0.1 mol/L)

C02 = factor for “normality“ (2)

C37 = titer of titrating agent (1.0013 common variable of “Tit.NaOH“) Compare also titration in non aqueous medium, application No. 1-5 For pK determinations, the electrode should be calibrated.

Answer

Oxalic = 4.098 x 0.1 x 1.0013 / 2 / 2 = 0.103 mol/L

EP1 = 2.110 mL

EP2 = 4.098 mL

C00 = 2 mL

Literature

Metrohm’s Teachware on CD-ROM

Penentuan analisis asam kuat dg alat Titrino / Titroprocessor

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0232.100 combined pH glass electrode; input 1

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

Sampel
2 mL c(HCl) = 0.1 mol/L 50 mL dist. Water

Rangkuman
Calculations:

C(acid) = EP1*C01*C37/C00 ; 3 ; mol/L

c(acid) = concentration of acid in mol/L
C01 = concentration of titrating agent (0.1 mol/L)
C37 = titer of titrating agent (1.0013 common variable of “Tit.NaOH“) Carbonate may be detected separately if present!

Answer
C(acid) = 1.996 x 0.1 x 1.003 / 2.00 = 0.100 mol/L
EP1 = 1.996 mL C00 = 2.00 mL

Literature
Metrohm’s Teachware on CD-ROM

Penentuan angka asam dg alat potensiometer

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0133.100 pH glass electrode; input 1
6.0726.100 Ag/AgCl double junction reference electrode
(LiCl sat. in ethanol)

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

Sample
app. 5-10 g sunflower oil
50 mL ethanol / diethylether (1 : 1), neutralized

Remarks
• Calculations:

Acid.No=EP1*C01/C00;2;mg/g
FFA=RS1*C02/C03;2;

Acid.No = acid number in mg KOH per g of sample
FFA = free fatty acid
C01 = mg KOH / 1 mL titrating agent (5.61)
C02 = relative molecular mass (282 for oleic acid)
C03 = factor (561)

. Answer

Acid.No = 0.150 x 5.61 / 10.3223 = 0.08 mg/g
FFA = 0.08 x 282 / 561 = 0.04

RS1 = 0.08
EP1 = 0.150 mL
C00 = 10.3223 g

Literature
• Metrohm Application Bulletin No. 141: Analysis of edible oils and fats.

Penentuan angka saponifikasi dg alat potensiometer

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0232.100 combined pH glass electrode; input 1

Pereaksi
c(HCl) = 1 mol/L; D0

Sampel
app. 2 g sunflower oil
25 mL c(KOH) = 0.5 mol/L in ethanol
app. 10-20 mL dist. water

Rangkuman
· Calculations:

Sapon.No=(C01-EP1)*C02/C00;1;mg/g

Sapon.No = saponification number in mg KOH per g of sample
C01 = consumption of blank sample (12.199 mL)
C02 = mg KOH / 1 mL titrating agent (56.1)

. Answer

Sapon.No = (12.199-5.271) x 56.1 / 2.0224 = 192.2 mg/g

EP1 = 5.271 mL
C00 = 2.0224 g

· Sample preparation:
Weigh out approx. 2 g sample in a round-bottomed flask. Add 25 mL alcoholic KOH solution plus a few boiling beads and allow to boil lightly for at least 30 min. Shake from time to time. Finally rinse the content of the round-bottomed flask into a beaker with a small quantity of dist. water and back titrate the excess of potassium hydroxide with HCl. A blank control sample should be prepared and treated identically. Enter the blank value as C01.

Literature
· Metrohm Application Bulletin No. 141: Analysis of edible oils and fats.

Penentuan angka angka Peroxide dg alat potensiometer

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0431.100 Pt Titrode; input 1

Pereaksi
c(Na2S2O3) = 0.01 mol/L; D0
Prepared daily from c = 0.1 mol/L

Sampel
app. 5 g sunflower oil
50 mL glacial acetic acid / chloroform (3 : 2)
1 mL KI saturate
100 mL dist. water

Remarks
· Calculations:

Perox.No=(EP1-C01)*C02/C00;2;meq/kg

Perox.No = peroxide number in meq.O2/kg
C01 = consumption of blank sample (0 mL)
C02 = factor (10)

. Answer

Perox.No = 0.8874 x 10 / 5.0188 = 1.77 meq/Kg

EP1 = 0.8874 mL
C00 = 5.0188 g

· Sample preparation:
Weigh out accurately 5 g sample in an Erlenmeyer flask and add 50 mL of the glacial acetic acid / chloroform mixture. Then add 1 mL of the KI solution and shake during 5 s. Now allow the mixture to stand for about 1 min. in a dark place. After this, rinse the contents of the
Erlenmeyer flask out into a beaker with 100 mL dist. water and immediately back-titrate the iodine thus liberated with sodium thiosulphate. A blank control sample should be prepared and treated in the same way. Enter the blank value as C01.
· The sample must be stirred well during the titration, in order to obtain
a good emulsion.

Literature
· Metrohm Application Bulletin No. 141: Analysis of edible oils and fats.

PENENTUAN ANALISIS KALSIUM DAN MAGNESIUM DALAM PRODUK SUSU

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor

Electrode = 6.0502.140 Cu2+ sensitive indicator electrode; input 1
6.0726.100 Ag/AgCl double junction reference electrode (KNO3 sat.)

Pereaksi
c(EGTA) = 0.1 mol/L; D0
c(Cu complex) = 0.100 mol/L; D1
Buffer solution pH = 10; D2

Sampel
app. 10 g milk

Remarks
· Calculations:

Calcium=C70*C01*C02*C03/C00;3;%

Calcium = content of calcium in %
C01 = concentration of titrating agent (0.1 mol/L)
C02 = molecular mass of calcium (40.08 g/mol)
C03 = factor for % (0.1)
C70 = EP1 from submethod Milk-Ca3

. Answer

Calcium = 3.008 x 0.1 x 40.08 x 0.1 / 10.0516 = 0.12%

C70 = 3.008

· Reagents:
c(EGTA) = 0.100 mol/L:
38.04 g EGTA - ethylene glycol-0,0’-bis-(2-aminoethyl)-N,N,N’,N’-tetraacetic acid are added to a 1 liter volumetric flask, dissolved in 250 mL c(NaOH) = 1 mol/L and the solution made up to the mark with dist. water.

Cu complex:
EGTA titrant (100 mL) is mixed with 100 mL of a solution containing 0.2 mol/L NH4Cl and exactly 0.100 mol/L Cu(II)nitrate. Titration can used to check that this solution contains no excess of Cu(II) or EGTA.

Buffer solution pH = 10:
54 g NH4Cl is dissolved in ca. 400 mL dist. water in a volumetric flask, 300 mL w(NH3) = 0.25 (25%) added and the solution made up to 1 liter with dist. water.

· The method „Milk-Ca3“ can also be used as work-alone method
(without TIP). Add the Cu complex-solution and the buffer solution
manually.

Literature
· Metrohm Application Bulletin No. 235: Potentiometric titration of Ca
(Mg) in milk products

Penentuan Formaldehyde Number di dalam jus buah dg alat potensiometer

Alat yg digunakan
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0232.100 combined pH glass electrode; input 1

Pereaksi
c(NaOH) = 0.1 mol/L; D0
w(HCHO) = 0.35 (35%), adjusted to pH = 8.5 with NaOH; D1

Sampel
25 mL sample (orange juice)

Electrodes
6.0232.100 combined pH glass electrode; input 1

Remarks
• Determination reaction:
OH
H2C=O + H2N-R Þ H2C + H+
NHR
Amino groups of amino acid react according to the above reaction.

• Calculations:

Formol No = C70*C01;1;

Formol No = formol number as mL NaOH 0.1 mol/L for 100 mLsample solution
C01 = factor for 100 mL sample solution (4)
• Calibrate the electrode for the SET titration.

. Answer

Formol No = 5.634 x 4 = 22.5

C70 = 5.634

Literature
• Metrohm Application Bulletin No. 180: Automatic determination of the
formol number in fruit and vegetable juices

Analisis garam di dalam kaldu

Equipment
Potentiometer = 751 GPD Titrino / Titroprocessor
Electrodes = 6.0430.100 Ag Titrode amalgamated; input 1

Reagents
c(AgNO3) = 0.1 mol/L; D0

Sample
20 mL sample solution
5 mL c(HNO3) = 2 mol/L
30 mL dist. Water

Remarks
• Calculations:

NaCl=EP1*C01*C02*C03/C00;2;%

NaCl = content of NaCl in broth in %
C00 = sample size (10 g / 100 = 0.1 g)
C01 = molecular mass of NaCl (58.44 g/mol)
C02 = concentration of titrating agent (0.1 mol/L)
C03 = factor for conversion mL Þ L and for % (0.001*100 = 0.1)

. Answer

NaCl = 8.070 x 58.44 x 0.1 x 0.1 / 0.1 = 47.16 %

EP1 = 8.070 mL
C00 = 0.1 g

• Sample preparation:
Dissolve 10 g (1 cube) conc. broth in 800 mL boiling dist. water. Rinse this solution in a 2000 mL measuring flask. Allow to cool down and fill up to the mark. Filter with a folded filter. Take 20 mL aliquots.

Literature
• Metrohm Application Bulletin No. 130: Chloride titrations with potentiometric end-point indication.