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Basics of Titration. by Michael Margreth. One of the oldest analytical methods Based on chemical reaction Determination of the volume of a standard solution (titrant) Standard solution contains a defined number of molecules Measuring volume = counting molecules TITRATION MEANS COUNTING!.
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Basics of Titration by Michael Margreth
One of the oldest analytical methods Based on chemical reaction Determination of the volume of a standard solution (titrant) Standard solution contains a defined number of molecules Measuring volume = counting molecules TITRATION MEANS COUNTING! Basics
Titrant Sample Titration Start
Titrant Titrant + Sample Titration Endpoint
Titrant Titrant + Sample Titration End
Titrant Color indicator Principle of a Manual Titration • - optical detection • manual control • manual addition
All in one! • Dosing • Measuring • Controlling • Evaluation
Titrations Modes • Set Endpoint Titration SET • Monotonic Equivalencepoint TitrationMET • Dynamic Equivalencepoint Titration DET • Karl Fischer Titration KFT
SetEndpointTitration Signal[pH/mV] endpoint volume
MonotonicEquivalence PointTitration Signal[pH/mV] equivalence point volume
DynamicEquivalence PointTitration Signal[pH/mV] equivalence point volume
In MET mode the steps are always the same In DET mode the steps are calculated by the Titrando EP1 EP1 Volume increment MET Mode DET Mode pH pH V [mL] V [mL]
Karl FischerTitration Signal[mg/min] Endpoint volume
Endpoint evaluation circle method derivative method tangent method
Titration steps • sample preparation (homogeneity) • right electrode choice • possibly electrode conditioning • titrant preparation • titer determination • buret/ sample size choice • correct arrangement in titration vessel • stirrer rate • method parameters • results calculation • report
stirrer electrode buret Arrangement
Titer • What is a titer? Correction factor • Why do we need the titer? To know the exact concentration of the titrant • What is the unit? none • How is the titer determined? With titrimetric standards • When do I have to determine a titer? frequently
Absolute method Easy to carry out Carried out very rapidly Versatile method Highly reproducible and correct results Can be automated economical Advantages
Hardware definition System
Method definition Parameters
4 default 0 high density 9 low density DET Mode DET Mode 8,5 8,5 8,0 8,0 7,5 7,5 pH pH EP1 EP1 7,0 7,0 6,5 6,5 6,0 6,0 -0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0 5,5 6,0 0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0 5,5 6,0 V [ml] V [ml] Measurement density