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Applications of liquid scintillation counting to radioimmunoassays
34
International Conferenceon Liquid Scintillation Countino
C-14 equilibrium. For beverages produced after the cessation of atmospheric testing the reduction of C-14 from about 28 dpm/gC can be used for the age determination. The optimization of the liquid resulted in a mixture of 5 ml of xylene and 20 ml of ethanol containig appropriate scintillators. Several examples of the application of this technique are presented. T H E USE OF L I Q U I D SCINTILLATION COUNTING IN T H E STUDIES OF COAL AND C O A L - D E R I V E D LIQUIDS K. Patel, R, J. Baltisberger, N. F. Woolsey, Department
oJ Chemistry, University of North Dakota, Grand Forks, North Dakota 58202 and W. E. Kisieleski, M. S. Matheson, Argonne National Laboratory, Argonne, Illinois 60439 Coal and coal-derived liquids were treated with radiolabeled (~4C or 3H) acetic acid, ethanol, methanol and water. Coal-derived liquids were allowed to react with 1-~4C-acetic anhydride in pyridine to form acetate derivatives of phenols and carbazoles. The labeled samples were then oxidized to either ~CO~ or aH20 which was collected and measured in a liquid scintillation counter. Good reproducibility and quantitative recovery of 14CO~2and 3H20 were observed. The liquid scintillation counting method was very useful for quantitation of phenols and carbazoles in coal-derived liquids. The amount of adsorption of acetic acid, ethanol, methanol and water was also measured. They were found to be irreversibly adsorbed on coal. Other techniques, such as IH and ~3C NMR, as well as titration of liberated acetic acid, are inefficient in quantitative determination of acid groups in coal. Only tracer methodology was able to determine adsorption of solvent on coal efficiently.
S E S S I O N L: A P P L I C A T I O N - - B I O M E D I C A L AND RADIOIMMUNOASSAYS APPLICATIONS OF L I Q U I D SCINTILLATION COUNTING TO RADIOIMMUNOASSAYS Grafton D. Chase, Department of Chemistry, Phila-
delphia College of Pharmacy and Science, Philadelphia, Pennsylvania 19104 Liquid scintillation counting (LSC) has proven to be a versatile counting technique for radioimmunoassay (RIA). Readily adaptable to the measurement of both beta and gamma emitting nuclides, LSC is useful for the measurement of all isotopes normally used in RIA. Of special need have been cocktail formulations designed for aqueous systems. Innovations resulting from adaptation of LSC to special RIA needs include physical modification of the elevator system and the use of adapters to accommodate RIA test tubes directly. A method using a modified LSC vial to position a microfuge tube in the center of a high-density cocktail has shown merit for the measurement of x rays and low energy gamma rays. Emphasis has been on counting efficiency, simplicity of operation and cost.
International Conferenceon Liquid Scintillation Countino
C-14 equilibrium. For beverages produced after the cessation of atmospheric testing the reduction of C-14 from about 28 dpm/gC can be used for the age determination. The optimization of the liquid resulted in a mixture of 5 ml of xylene and 20 ml of ethanol containig appropriate scintillators. Several examples of the application of this technique are presented. T H E USE OF L I Q U I D SCINTILLATION COUNTING IN T H E STUDIES OF COAL AND C O A L - D E R I V E D LIQUIDS K. Patel, R, J. Baltisberger, N. F. Woolsey, Department
oJ Chemistry, University of North Dakota, Grand Forks, North Dakota 58202 and W. E. Kisieleski, M. S. Matheson, Argonne National Laboratory, Argonne, Illinois 60439 Coal and coal-derived liquids were treated with radiolabeled (~4C or 3H) acetic acid, ethanol, methanol and water. Coal-derived liquids were allowed to react with 1-~4C-acetic anhydride in pyridine to form acetate derivatives of phenols and carbazoles. The labeled samples were then oxidized to either ~CO~ or aH20 which was collected and measured in a liquid scintillation counter. Good reproducibility and quantitative recovery of 14CO~2and 3H20 were observed. The liquid scintillation counting method was very useful for quantitation of phenols and carbazoles in coal-derived liquids. The amount of adsorption of acetic acid, ethanol, methanol and water was also measured. They were found to be irreversibly adsorbed on coal. Other techniques, such as IH and ~3C NMR, as well as titration of liberated acetic acid, are inefficient in quantitative determination of acid groups in coal. Only tracer methodology was able to determine adsorption of solvent on coal efficiently.
S E S S I O N L: A P P L I C A T I O N - - B I O M E D I C A L AND RADIOIMMUNOASSAYS APPLICATIONS OF L I Q U I D SCINTILLATION COUNTING TO RADIOIMMUNOASSAYS Grafton D. Chase, Department of Chemistry, Phila-
delphia College of Pharmacy and Science, Philadelphia, Pennsylvania 19104 Liquid scintillation counting (LSC) has proven to be a versatile counting technique for radioimmunoassay (RIA). Readily adaptable to the measurement of both beta and gamma emitting nuclides, LSC is useful for the measurement of all isotopes normally used in RIA. Of special need have been cocktail formulations designed for aqueous systems. Innovations resulting from adaptation of LSC to special RIA needs include physical modification of the elevator system and the use of adapters to accommodate RIA test tubes directly. A method using a modified LSC vial to position a microfuge tube in the center of a high-density cocktail has shown merit for the measurement of x rays and low energy gamma rays. Emphasis has been on counting efficiency, simplicity of operation and cost.