rattus labbus - PowerPoint PPT Presentation

Title: rattus labbus


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Welcome!
Please click the left mouse button repeatedly to
move through the slide show
. to this brief introduction to the MULTITRATOR
multi-mode titration system
rattus labbus (Multitrator employee)
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starting with a definition .
titrate /'tuytrayt/ verb (t) (titrated,
titrating) to ascertain the quantity of a given
constituent present in (a solution) by accurately
measuring the volume of a liquid reagent of known
strength until an end point is reached. F titrer
titrate -ate1. See titre --titration
/tuy'trayshuhn/, n. - The Macquarie Dictionary
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Thermometric Titrimetry

. Is a titration technique where endpoints
are revealed by the rate of temperature change
of the solution temperature.
. A thermistor is conveniently used to
measure the change in temperature.
. Because only the rate of temperature
change is important, it is unnecessary to
calibrate the thermistor.
. Both exothermic and endothermic
reactions between a titrant and an analyte may be
used to define endpoints.
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another definition .
thermistor /ther'mistuh/ noun an electronic
semiconductor, the resistance of which decreases
rapidly with increase in temperature. therm-
(trans)istor or therm- (res)istor - The
Macquarie Dictionary
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The business end of Multitrator
Multitrator thermometric probe
Temperature-sensing thermistor bead (1.5mm
diameter)
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Thermometric titrimetry can perform .
? Acid/base (including weak acid/weak base)
? Redox
? Complexometric (eg, EDTA)
? Precipitation titrations (eg, Cl- with Ag,
SO42- with Ba2, F- as NaK2AlF6)
? Non-aqueous (eg, free fatty acids
in edible fats oils)
? Moisture (endothermic reaction of water
with triethyl orthoformate)
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Thermometric titration plots .
EXAMPLE OH- and CO3--
Endpoint 2 (HCO3-)
Endpoint 1 (OH-)
Solution temperature
Second derivativecurve for accurate location of
endpoints
Volume of titrant added
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Thermometric titration of phosphoric acid with
sodium hydroxide
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The difference between potentiometric and
thermometric titrimetry.
Potentiometric (eg, pH) titrations are free
energy controlled ?Go -RTlnK
Thermometric titrations are enthalpy
controlled ?Ho ?Go T?So
In any reaction where the free energy does not
oppose the entropy change, thermometric
titrations will generally give sharper endpoints
than potentiometric titrations
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The difference between potentiometric and
thermometric titrimetry.
Thermometric titrimetry is a linear titration
technique, wherein the signal is proportional to
the amounts reacted
Potentiometric titrimetry is a logarithmic
technique, relying on the magnitude of
equilibrium constants to obtain an inflection
Where equilibrium constants are small (eg.,
titration of weak acids), thermometric titrimetry
is generally superior
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Thermometric versus potentiometric (pH)
titrations .
Simultaneous potentiometric (pH) and thermometric
titration of acidic components in red wine
pH endpoints tagged blue
Thermometric endpoints tagged red.
pH titration curve
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Sensitivity of Thermometric Method
Example Determination of Chloride in Water
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Water, water, everywhere .
The thermometric titration way to determine
moisture
HC(OCH2CH3)3 3H2O
Triethyl orthoformate (TEOF)
H
HCOOCH2CH3 2CH3CH2OH

• TEOF doesnt react with water until
  acid-catalyzed in the sample solution
• indefinite shelf life
• benign reaction products

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H2O in lubricating oils.
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Catalytic Endpoint Thermometric Titrimetry (CETT)
Example Analysis of weakly acidic species in
non-aqueous media using 0.1mol/L KOH in
propan-2-ol
Glass membrane pH probes rapidly dehydrate and
lose response in non-aqueous solutions
A thermometric probe is unaffected, but small
heat of reaction is swamped by heats of solution
and other thermal effects
The solution use an indicator system where the
first excess of OH- catalyzes a strong exothermic
reaction which serves to indicate the endpoint
CHCl3 OH- ? CCl3- H2O CCl3- (CH3)2CO H2O
? (CCl3)(CH3)2C-OH OH-
Smith, T. K. (2003) JAOCS 80 21-24
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Catalytic thermometric titration of FFA in edible
oils
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Thermometric titrimetry is a well established
technique
1886 Analysis of fuming sulphuric acid with
dilute sulphuric acid (Howard)
1913 Titration of citric acid with ammonia
(Bell Cowell)
1920s Analysis of polyprotic acids, acid
mixtures with Beckman thermometers.
1940s Introduction of thermopiles highly
accurate redox titrations.
1950s Introduction of thermistors
1960s Introduction of digital burettes first
automated thermometric titrators.
Late-1980s First computer-controlled
thermometric titrator
1999 Multitrator founded first fully-automated
multi-mode titration system featuring
thermometric titrimetry.
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Multitrator - titration for now!

• Computer controlled

• Powerful software

• Integrated with MS Excel

• Compact control module

• Easy to use

• Good ergonomics

• Fast sample turnaround

Advanced, multi-sensor technology not just
thermometric!
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Multitrator most versatile!
? Titrations with potentiometric (pH, redox,
ISE), photometric, chemiluminescence,
conductometric, either alone or multiplexed
with other sensors.
? Add sample changers, auto-samplers, auto-pipett
es, pumps, valves and switches for full
automation.
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Chemiluminescent titrations for trace acids..
A technique where the sensor never touches the
solution
Open air demo of a chemiluminescent titration
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Multitrator Chemiluminescent Titration Module
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Sensitive, fast pH titrations with Multitrator.
Solid-state ISFET (Ion Selective Field Effect
Transistor) pH probes are much, much faster than
glass pH probes, but need the great Multitrator
signal conditioning algorithm to get the most out
of them..
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Check out whats under the hood ...
Power supply 90-260 VAC 50-60 Hz
Communication to computer
Communication to burettes and sample changer
Communication to RS422/485 devices
Analogue inputs, digital outputs relays,
solenoids, pumps
Serial comms port for microcontroller devices
Multi-purpose sensor port
Potentiometric sensor port
Thermometric sensor port
Additional thermometric sensor ports
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The simplest solution for full titration
automation

• The same thermometric sensor used for most
  determinations

• Perform different types of titration in the same
  carousel load

• Daisy-chain up to 8 burettes

• Import method and sample data from a LIMS

• Control entire sequence with a single mouse click

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ending with a definition .
multitrate /muhltitrayt/ verb (t)
(multitrated, multitrating) to conduct a
titration using the most versatile and advanced
multi-mode titration system, esp. using
thermometric titrimetry L multus much, many F
titrer titrate -ate1. - Lab Rat Dictionary