Titration calorimeter

Instrumentation. H and NMR spectra were recorded on a Bruker AV 400 spectrometer (400.2 MHz for proton and 100.6 MHz for carbon) at 310 K. Chemical shifts (< are expressed in ppm coupling constants (J) in Hz. Deuterated DMSO and/or water were used as solvent chemical shift values are reported relative to residual signals (DMSO 5 = 2.50 for H and 5 = 39.5 for C). ESl-MS data were obtained on a VG Trio-2000 Fisons Instruments Mass Spectrometer with VG MassLynx software. Vers. 2.00 in CH3CN/H2O at 60°C. Isothermal titration calorimetry (ITC) experiments were conducted on a VP isothermal titration calorimeter from Microcal at 30°C. 

Methods. The equipment used consists of a TRONAC Model 450 (TRONAC, Inc., Orem, Utah) isoperibol titration calorimeter which... 

The historical development of titration calorimetry has been addressed by Grime [197]. The technique is credited to have been born in 1913, when Bell and Cowell used an apparatus consisting of a 200 cm3 Dewar vessel, a platinum stirrer, a thermometer graduated to tenths of degrees, and a volumetric burette to determine the end point of the titration of citric acid with ammonia lfom a plot of the observed temperature change against the volume of ammonia added [208]. The capabilities of titration calorimetry have enormously evolved since then, and the accuracy limits of modern titration calorimeters are comparable to those obtained in conventional isoperibol (chapter 8) or heat-flow instruments (chapter 9) [195,198],... 

The accuracy of a titration calorimeter is normally assessed using the reactions of NaOH(aq) with HCl(aq) or HCICUjaq) [209,210], The dissolution of crystalline tris(hydroxymethyl)aminomethane (THAM) in HCl(aq) has also been employed when the apparatus is equipped with a system for the introduction of solid samples (e.g., an ampule breaking device) [210]. As mentioned in chapter 8, the latter method is commonly recommended for testing conventional reaction-solution calorimeters [39,40]. 

D. J. Eatough, J. J. Christensen, R. M. Izatt. Determination of the Enthalpy ofSolution ofTris-(hydroximethyl)aminomethane in 0.1 M HCl Solution and the Enthalpy of Neutralization ofHClO4 with NaOH at Low Ionic Strengths by Use of an Improved Titration Calorimeter. J. Chem. Thermodynamics 1975, 7, 417—422. 

Wieseman, T Williston, S., Brandts, J.F., Lin, L.-N. (1989). Rapid measurement of binding constants and heats of binding using a new titration calorimeter. Anal. Biochem. 179, 131-137. 

Zhang Baolin, Interactions of Amino Acids with Ion Exchanger and plication of Titration Calorimeter, M. S. thesis, Lanzhou University, 1989. Zhang Baolin, Wang Wenqing, Li Zhong, and Tao Zuyi, Chem. J. Chinese Univ., 12 1522 (1991). 

I would like to thank Drs. R. London, J. Falke and D. LeBlanc for helpful discussions. I would also like to thank Dr. Eric Toone for use of his titrating calorimeter. Grant T32 HL 07594 supported preliminary work for this project. Lastly, I am deeply indepted to Dr. Steve Withers for initiating this project. 

A large variety of analysers such as ion chromatographs, mass spectrometers, digital titrators, calorimeters, specific ion analysers, gas and liquid chromatographs and octane number analysers are manufactured with built-in microprocessors. 

Figure 7.22 Schematic diagram of Isothermal titration calorimeter (ITC) device showing how a solution of receptor R is maintained in an ITC cell within an adiabatic shield and ligand L is injected in with stirring from above.

Figure 5. ITC measurements ofholo frataxin binding to D37A human ISU were carried out at 27 ""C on a MicroCal ultrasensitive titration calorimeter. All samples were in degassed 50 mMHEPES (pH 7.5) buffer. A7 pL aliquot of a 0.5 mMsolution of titrant was delivered over 10 s to 0.03 mMholo frataxin with an adequate interval (10 min) between injections to allow complete equilibration.

Woycicki investigated binary mixtures, i.e. -hexane with l- -hexyne or with 3- -hexyne as well as n-heptane with w-heptyne and also a second series, namely tetrachloromethane with 1-n-hexyne, 3- -hexyne or l- -heptyne. Molar excess heats of mixing were measured in a continuous titration calorimeter of the Becker-Kiefer type over a wide concentration range at 298.15 K. The method has been described else-where . The purities of all substances were determined by g.l.c. and were better than 99.31%. 

The instrument can also be described further in terms of technical characteristics that are self-explanatory to the specialist. Examples are the titration calorimeter, bomb calorimeter, gas calorimeter, fiow calorimeter, drop calorimeter, heat flow calorimeter, and ice calorimeter. The designation microcalorimeter should be avoided because it does not show whether the term micro refers to the size of the device, the sample container, or the quantity of heat measured. 

High-predsion versions of isothermal titration calorimeters (ITCs) are commercially available ... 

Isothermal titration calorimeter. The instrument used for these studies was purchased from Microcal, Inc., Northhampton, MA. 

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