i onanalysis 859 titrotherm thermometric titrator the ideal complement to potentiometric titration
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what is a thermometric titration titration is the oldest and most widespread method used in analytical chemistry for a long time now potentiometric sensors indicator electrodes have been used to cover a wide range of applications in the titration field as a result potentiometric titration has become firmly established and features in many standards however a suitable indicator electrode is not always available for an existing problem there may be no suitable sensor for the analyte at hand or the sample matrix can either interfere with the indicator electrode or even render it unusable the electrochemical potential is only one of the possible ways of following a chemical reaction a far more universal parameter is the reaction enthalpy every chemical reaction is accompanied by a change in enthalpy h the following equation applies hgts g ts where change in free reaction energy absolute temperature change in reaction entropy as long as the reaction takes place this results in either
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advantages of thermometric titration · proven method · problem solver for difficult samples that cannot be titrated potentiometrically · rapid results · no sensor calibration required · maintenance-free sensor · robust method for routine work · well suited for aggressive media · one sensor for all applications · no membrane or diaphragm problems 3
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859 titrotherm can you feel the heat the 859 titrotherm combines innovative sensor technology with metrohm s titration know-how 859 titrotherm most modern usb technology the 859 titrotherm s easy operation becomes apparent even during installation thanks to advanced usb technology the instrument is recognized when it is connected to the pc and does not have to be manually configured the same applies to the dosing units stirrers and sensors connected to the 859 titrotherm 4
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the software everything at a glance everything under control the clearly laid out titrotherm software allows adaptation of the screen view to the particular method parameters and thus provides rapid access to important commands or parameters the endpoints are determined by calculating the first and second derivatives of the titration curve by means of additional optimization parameters the reproducibility can be improved even further for report generation the titration data can be exported manually or automatically into a freely arranged method-specific report form 5
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thermoprobe quick precise and robust thermoprobe a temperature sensor based on semiconductor technology thermistor has a response time of 0.3 s and a resolution of 105 k this makes the thermoprobe the ideal sensor for thermometric titration as it can follow any change in temperature quickly and accurately the housing made of polypropylene pp and epoxy resin provides the sensor with outstanding resistance to many organic solvents and aggressive media dosino technology precise and simple dosing metrohm s dosino technology has defined a new standard for volumetric titration the dosing unit with its drive motor is mounted on the reagent bottle and thus guarantees maximum precision with minimum space requirements the titrator and two burets require hardly more bench space than a sheet of din a5 paper 7
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scope of thermometric titration thermometric titration is a very versatile determination method and an ideal complement to potentiometric titration in principle it is suitable for any reaction that produces a sufficiently large temperature change in the sample solution it is particularly suitable for applications · · · · for which no suitable potentiometric sensor is available for which no suitable reference electrode is available in which the sample affects the indicator electrode or destroys it for which no solvent is available that is suitable for potentiometry typical applications for thermometric titration analyte sulfate phosphate nickel acid mixtures matrix phosphate-containing solutions buffer ph 10 nh3/nh4cl ore leachates electroplating baths containing hf titrant ba2 mg2 dimethylglyoxime naoh application example 1 determination of sulfate and total acid in a nitrating acid mixture nitric acid/sulfuric acid this application demonstrates the flexibility of thermometric titratio
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application example 2 analysis of an acid mixture comprising acetic nitric and phosphoric acid this acid mixture used in the semiconductor industry can only be analyzed if the third endpoint which is entirely due to the third proton of the phosphoric acid can be unequivocally determined using a normal ph electrode in aqueous solution this would be impossible as the electrochemical dissociation potential is too low thermometric titration however allows the determination of the third endpoint very easily and above all very rapidly the individual acid concentrations can then be calculated from the separations between the endpoints reagents titrant cnaoh 1 mol/l solvent deionized water titration rate 2 ml/min procedure transfer 40 ml deionized water into the titration vessel add 2.5 ml acid mixture and titrate with cnaoh 1 mol/l 9
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catalytically enhanced thermometric titration at very low sample concentrations or with low molar reaction enthalpies the temperature change during the reaction is often inadequate for the reliable determination of the endpoint with a clever trick it is possible to obtain a proper «jump» in such reactions an example is the determination of very small amounts of organic acids with the titrant ckoh 0.1 mol/l in isopropanol in this case the addition of a small amount of paraformaldehyde makes it easier to detect the endpoint for as soon as the endpoint is reached i.e as soon as excess hydroxide ions are present the base-catalyzed hydrolysis of the paraformaldehyde starts this strongly endothermal reaction now provides a wellmarked endpoint catalytically enhanced thermometric titration after the endpoint has been reached the excess hydroxide ions catalyze the endothermal hydrolysis of the added paraformaldehyde 10
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ordering information 2.136.0010 859 titrotherm usb-enabled thermometric titrator with two measuring inputs for thermoprobe an adapter allows to connect a combined ph glass electrode four msb connections for 800 dosinos and stirrer including thermoprobe adapter for combined ph or metal electrodes with plug f cable usb a mini-din 8 pins 859 titrotherm cd-rom rel 1 optional accessories dosino 804 titration stand without stand rod rod stirrer dosing unit 20 ml stand rod with base plate clamping ring electrode holder system requirements for titrotherm software pentium 4 clock frequency 1 ghz 512 mb 150 mb for program windows® 2000 sp1 windows® xp professional free usb connection 6.9011.020 6.9011.030 6.2151.000 a.712.0001 2.800.0010 2.804.0010 2.802.0010 6.3032.220 6.2026.010 6.2013.010 6.2021.020 processor ram free hard-disk memory operating system connections 11
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i onanalysis metrohm ltd ch-9101 herisau/switzerland phone +41 71 353 85 85 fax +41 71 353 89 01 www.metrohm.com info@metrohm.com www.titrotherm.com subject to modifications layout by ecknauer+schoch asw printed in switzerland by metrohm ltd herisau 8.859.6003 2007-01
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