Radiochemistry Past Paper (STSN 2132 #1) PDF

11/19/24 Radiochemistry 20 Synopsis 24 This course provides an introduction to the basic theory, advancements in...

11/19/24 Radiochemistry 20 Synopsis 24 This course provides an introduction to the basic theory, advancements in analytical methods, preparation of samples and standards, and analytical procedures. Data analysis will also be covered. Among the analytical techniques discussed are neutron activation analysis (NAA), which includes its principles and applications, sample activation, preparation of STSN 2132 #1 primary and secondary standards, and activation involving fast, epithermal, thermal, and charged particles. We'll also delve into NAA instrumentation, specifically the ko standard and comparative methods. Tracers in chemical Tracer in Chemical Analysis: analysis will be explored, including radiometric titration, isotope dilution techniques, radioimmunoassay, and autoradiography. We'll also discuss Radiometric Titration environmental radionuclide analysis and nuclear dating methods such as helium-uranium, rubidium-strontium, radiocarbon, and tritium. Other techniques like XRF, XPS, and PIXE will also be covered. Assoc. Prof. Dr. Khoo Kok Siong Dr. Syazwani Mohd Fadzil 1 2 1 2 Course Outcome (CO) CO1 Explain the theory and practical aspects of the neutron activation analysis based on instrumentation and radiochemical methods. CO2 Use radioactive tracers in chemical analysis and chemical separation. CO3 Analyse and measure the environmental radionuclides. CO4 Identify nuclear analysis techniques such as XRF, XPS and PIXE. 3 4 3 4 1  11/19/24 5 6 5 6 Textbooks Assessment 1. Rosch, F. 2014. Nuclear and Radiochemistry: An Introduction (De Gruyfer Textbook). Walter de Gruyfer Inc. 2. Choppin, G., Liljenzin, J.O., Rydberg, J., Ekberg, C. 2013. Radiochemistry and Nuclear Chemistry. Elsevier. 3. Choppin, G.R., Liljenzin, J.O. & Rydberg, J. 2002. Radiochemistry and nuclear chemistry. Woburn: Butterworth-Heinemann. 4. Sarmani, S. 1991. Radiokimia. KL: DBP. 5. Friedlander, G., Kennedy, J.W., Macias, E.S. & Miller, J.M. 1981. Nuclear and radiochemistry. 3rd ed. New York: John Wiley. 7 8 7 8 2  11/19/24 Brief History of Radiochemistry 1923 George Hevesy demonstrates the distribution of radioactive lead in growing bean plants (1943 Nobel Prize in chemistry). 1895 William Roentgen discovers X-rays (1901 Nobel Prize in Physics). 1931 Earnest Lawrence at the University of California, Berkeley invents the cyclotron. 1896 Henry Becquerel discovers natural radioactivity of uranium (1903 Nobel Prize in physics). 1934 Irene and Frederic Joliot- Curie produce the first artificial radioisotopes (1934 Nobel Prize in physics). 1898 Pierre and Marie Curie discover polonium and radium (1903 Nobel Prize in physics). 1935 Earnest Lawrence produces radioactive isotopes of sodium by using his new cyclotron. Over the next few years he manufactures another 17 1900 Ernest Rutherford: Demonstrates that radioactivity is due to the biologically useful radioisotopes. transmutation of elements, introducing the concept of half-life for radioactive decay. 1938 Otto Hahn, Lise Meitner, and Fritz Strassmann: Discover nuclear fission, leading to the understanding of the enormous energy potential of certain 1902 Rutherford and Frederick Soddy: Propose that radioactivity is due to the radioactive materials. spontaneous disintegration of atoms. They introduce the "disintegration theory." 1939 Joseph Hamilton uses iodine-131 for diagnostic purposes in patients. 1911 George Hevesy uses radioactive lead as a tracer to proof left-over food 1940s Manhattan Project: Large-scale radiochemical procedures are developed being recycled into his meals (the Father of Nuclear Medicine). for the separation and purification of plutonium and uranium, leading to the construction of the atomic bomb. 1913 Kasimir Fajans and Soddy: Develop the "displacement laws" for α and β decay, laying the foundation for the understanding of radioactive decay series 9 10 9 10 1942 The first nuclear reactor is constructed and operated at Oak Ridge National Laboratory (the Manhattan Project). 1980s Radiopharmaceuticals: Growth in the application of radiochemistry in medicine, with radioisotopes being used for diagnosis and treatment. 1946 Radioisotopes produced from the above nuclear reactor become available for research 1990s Green Radiochemistry: Emphasis on minimizing radioactive waste and developing environmentally-friendly radiochemical processes. 1950s Radiotracer Technique: Introduction and development of radiotracers for medical, industrial, and environmental applications. 2000s Advanced Nuclear Fuel Cycles: Research intensifies on reprocessing spent nuclear fuel to reduce waste and increase fuel efficiency. 1951 Benedict Cassen at the University of California, Los Angeles invents the scintiscanner for the measurement of radioiodine in the body (the first 2010s Single Atom Chemistry: With advancements in instrumentation, step toward PET). researchers begin studying the chemistry of individual radionuclides. 1958 Hal Anger develops the Anger Camera, which permitted visualization of radiotracer distribution in biological systems. 1960s Transactinide Elements: Further exploration and synthesis of superheavy elements, extending the periodic table. 1970s High-level Waste Research: Focus shifts towards developing methods to manage and reduce the volume of radioactive wastes from nuclear power plants. 1975 A former Golden Gloves boxer Michael Phelps and Edward Hoffman in Ter-Pogossian’s laboratory develop PETT (Positron Emission Transaxial Tomography). 11 12 11 12 3  11/19/24 Use of Radioisotopes in Biological Sciences 13 14 13 14 Methods of Detecting Radioisotopes Quantifying the Amount of a Radioisotope in a Sample Geiger Counter detects b particles by the ionization they produce in a gas Scintillation Counter detects b particles by the small flashes of light they induce in a scintillation fluid 15 16 15 16 4  11/19/24 Applications of Radioisotopes Radiometric Titration 1. Detection of specific molecules in samples Radiometric titration is a type of titration in which radioisotopes are used as tracers to follow the progress of 2. Measurement of biological processes the reaction or to determine the endpoint of the titration. 3. Measurement of enzymatic activities The principle underlying this method is similar to other titration methods, but instead of observing a physical 4. Tracking the fate of specific molecules (pulse-chase) change (like color change in conventional titration), one measures the radioactivity. 17 18 17 18 Advantages of Radiometric Titration: Principle of Radiometric Titration: 1. Sensitivity: Radiometric titration can detect very low concentrations due to 1. A known quantity of radioactive tracer is added to the the high sensitivity of radioactive decay detection. sample. 2. Specificity: Because radioisotopes can be selected or produced to have specific chemical properties, radiometric titration can be highly specific. 2. The sample is then titrated with a titrant. 3. Versatility: It can be applied where traditional indicators are ineffective or 3. As the titration progresses, the tracer either becomes where other methods are not feasible. bound or released, changing the radioactivity of the 4. Quantitative: The method allows for a direct quantitative measure of the analyte of interest. solution. Disadvantages of Radiometric Titration: 4. The endpoint is determined by monitoring the change 1. Handling of Radioactive Materials: There's an inherent risk in dealing with in radioactivity. radioactive substances. Proper precautions and protocols need to be followed to ensure safety. 2. Potential for Radioactive Waste: Radioactive decay products and any unused radioactive tracers can pose disposal challenges, as they need to be handled and stored in a way that doesn't harm the environment or living organisms. 3. Need for Specialized Detection Equipment: Unlike conventional titration methods, radiometric titration requires specific and often expensive instrumentation to detect and measure radioactivity. This can increase the overall cost and complexity of the analysis. 19 20 19 20 5  11/19/24 Applications: 1. Study of Complex Formation: Radiometric titration is useful in studying the formation of complexes in solution, especially when one of the components can be radioactively labeled. 2. Determination of Metal Ions: Especially those that do not easily lend themselves to conventional titration methods. 3. Pharmaceutical Analysis: Used for the determination Limitation of certain drugs and their pharmacokinetics. Requirement of phase separation method 21 22 21 22 2. Determination of Metal Ions: Example: Determination of Mercury Ions 1. Study of Complex Formation: Example: Determination of Stability Constants of Metal a) Using radiolabeled mercury (like Hg-197), one can determine the concentration of mercury ions in a sample. As a chelating agent or Complexes ligand is titrated into the sample, it will bind to the mercury ions, causing a measurable change in the radioactivity of the solution. The endpoint of A typical study might involve the determination of the stability the titration can be determined by the maximum change in radioactivity, constant of a metal complex using a radioactive metal ion. For signifying all the mercury ions have been complexed. instance, the stability constant of a copper-ammonia complex b) The determination of sulfate ions in a solution using a barium tracer. can be determined using copper-64 (a radioactive isotope of Barium-133 (a radioisotope) is added to the solution, and the sulfate copper). As the titration progresses and ammonia is added to a ions form an insoluble precipitate with barium ions. As the titration solution containing Cu-64, the formation of the complex progresses and the sulfate is precipitated out, the radioactivity in the causes a change in the distribution of the radioactivity between solution decreases. Monitoring this decrease in radioactivity can allow the solution and a solid phase, or between two immiscible for the precise determination of the sulfate concentration. liquid phases. By monitoring the radioactivity change, the stability constant of the complex can be determined. 23 24 23 24 6  11/19/24 3. Pharmaceutical Analysis: Example: Determination of Drug Binding to Plasma Proteins Radiometric Titration This is an important parameter in pharmacokinetics. A drug can be radiolabeled (for instance, with tritium, H-3, or carbon-14, C-14) and then introduced into a plasma sample. As the drug binds to plasma proteins, its distribution between the bound and unbound states will change. By titrating with a known displacer or by changing the plasma concentration and then monitoring the radioactivity of the free drug fraction, Type I one can determine the extent of drug binding to plasma Type II proteins. Type III Reagent is a substance or compound added to a system to cause a chemical reaction, or added to test if a reaction occurs. Titrant is a solution of known concentration which is added (titrated) to another solution to determine the concentration of a second chemical species. Analyte or titrand is the species of interest during a titration. 25 Source: kolloid.unideb.hu/wp-content/uploads/2013/12/radiometric-titration.pdf 26 25 26 'Titrant' is the compound in the titration buret, mostly its concentration is exactly known. 'Titrand' is the substance which is being analysed in the titration Solution/Titrand 27 https://www.bcp.fu-berlin.de/chemie/ 28 https://www.bcp.fu-berlin.de/chemie/ 27 28 7  11/19/24 Type II Type III Use of radioactive indicator to track the transfer of material between two liquid phases in equilibrium Source: kolloid.unideb.hu/wp-content/uploads/2013/12/radiometric-titration.pdf 29 30 29 30 31 32 31 32 8  11/19/24 Example (Type I) A typical example of radiometric titration is for the determination of halides using 110Ag (t1/2 = 252 d) as tracer where corresponding silver halide is precipitated. Consider the titration of 10 mL of 1mM NaCl solution containing Cl- with 1 mM solution of 110AgNO3 to follow the reaction: 110AgNO + NaCl- → 110AgCl (ppt) + NaNO 3 3 Activity of the supernatant solution is monitored after equilibrium is attained following the addition of titrant. Initially solution containing NaCl has no activity. With the addition of increasing amount of 110AgNO3, supernatant will have very little or insignificant activity because all the activity would have gone to the precipitate of 110AgCl. After the end point, however, activity of 110AgNO will come into the solution and keep 3 increasing with every additional drop. Titration data are plotted. Equivalence point is the intercept of the two straight lines of the curve. http://www.expertsmind.com 33 34 33 34 35 35 9