Academic Press Rapid Manuscript Reproduction Proceedings of the International Conference on Liquid Scintillation: Science and Technology held at the Banff Centre in Alberta, Canada on June 14-17,1976 Liquid Scintillation SCIENCE AND TECHNOLOGY Edited by A. A. Noujaim C. Ediss L. I. Weibe Faculty of Pharmacy and Pharmaceutical Sciences University of Alberta Edmonton, Alberta Canada ® Academic Press, Inc. New York San Francisco London 1976 A Subsidiary of Harcourt Brace Jovanovich, Publishers COPYRIGHT © 1976, BY ACADEMIC PRESS, INC. ALL RIGHTS RESERVED. NO PART OF THIS PUBLICATION MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM OR BY ANY MEANS, ELECTRONIC OR MECHANICAL, INCLUDING PHOTOCOPY, RECORDING, OR ANY INFORMATION STORAGE AND RETRIEVAL SYSTEM, WITHOUT PERMISSION IN WRITING FROM THE PUBLISHER. ACADEMIC PRESS, INC. Il l Fifth Avenue, New York, New York 10003 United Kingdom Edition published by ACADEMIC PRESS, INC. (LONDON) LTD. 24/28 Oval Road, London NW1 LIBRARY OF CONGRESS CATALOG CARD NUMBER: 76-44559 ISBN 0 - 1 2 - 5 2 2 3 5 0 - 1 PRINTED IN THE UNITED STATES OF AMERICA List of Contributors Abrams, D.N., Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada Apelgot, S., Laboratoire Curie de la Fondation Curie, Institut du Radium, 11 Rue P. et M. Curie, 75231 Paris, Cedex 05, France Bransome, E.D. Jr., Department of Medicine, Medical College of Georgia, Augusta, Georgia 30902, U.S.A. Buess, EM., Division of Biological and Medical Research, Argonne National Laboratory, Argonne, Illinois 60439, U.S.A. Burnham, J., Manager, Health Physics, New Brunswick Power, 527 King Street, Fredericton, New Brunswick, E3B 4X1, Canada Carter, T.P., Faculty of Medicine, Radioisotope Counting Services, Medical School, University of Birmingham, Engrasson, Birmingham, B15 2TJ, England Demulyder, F., Vrije Universiteit Brüssel, Laboratorium voor Biochemie, Brussels, Belgium DeRycker, J., Vrije Universiteit Brüssel, Laboratorium voor Biochemie, Brussels, Belgium Duquesne, M., Laboratoire Curie de la Fondation Curie, Institut du Radium, 11 Rue P. et M. Curie, 75231 Paris, Cedex 05, France Ediss, C, Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada English, D., W.W. Cross Cancer Institute, Edmonton, Alberta, T6G 1Z2, Canada ix LIST OF CONTRIBUTORS Erwin, W., Laboratory of Chemical Biodynamics, Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720, U.S.A. Ferris, R., Amersham/Searle Corp., 2636 S. Clearbrook Drive, Arlington Heights, Illinois 60005, U.S.A. Gibson, J.A.B., Environmental and Medical Sciences Division, Atomic Energy Research Establishment, Harwell, Oxon, England Gordon, B.E., Laboratory of Chemical Biodynamics, Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720, U.S.A. Horan, T., W.W. Cross Cancer Institute, Edmonton, Alberta T6G 1Z2, Canada Horrocks, D.L., Scientific Instruments Division, Beckman Instruments Inc., Irvine, California 92713, U.S.A. Kelly, M.J., Beckman Instruments Inc., Scientific Instruments Division, Irvine, California 92713, U.S.A. Kisieleski, W.E., Division of Biological and Medical Research, Argonne National Laboratory, Argonne, Illinois 60439, U.S.A. Kohler, V., Scientific Instruments Division, Beckman Instruments Inc., Irvine, California, 92713, U.S.A. Laney, B.H., Searle Instrumentation, 2000 Nuclear Drive, Des Plaines, Illinois 60018 Lemmon, R.M., Laboratory of Chemical Biodynamics, Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720, U.S.A. Long, E., Beckman Instruments Inc., Scientific Instruments Division, Irvine, California 92713, U.S.A. McDowell, W.J., Chemical Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, U.S.A. McPherson, T.A., W.W. Cross Cancer Institute, Edmonton, Alberta, T6G 2H7, Canada McQuarrie, S.A., Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta T6G 2H7, Canada x LIST OF CONTRIBUTORS Nookes, J.E., Geochronology Laboratory, University of Georgia, Athens, Georgia 30601, U.S.A. Noujaim, A.A., Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta T6G 2H7, Canada Painter, K., Dept. of Radiology and Radiation Biology, Colorado State University, and Micromedic Diagnostics Inc., Fort Collins, Colorado 80521, U.S.A. Peng, C.T., Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco, California 94143, U.S.A. Polic, E., Packard Instrument, Downers Grove, Illinois 60515, U.S.A. Press, M., Laboratory of Chemical Biodynamics, Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720, U.S.A. Reid, W., University Hospital, Saskatoon, Saskatchewan, Canada Roosens, H, Vrije Universiteit Brüssel, Laboratorium voor Biochemie, Brussels, Belgium Ross, H.H., Analytical Chemistry Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, U.S.A. Schräm, E., Vrije Universiteit Brüssel, Laboratorium voor Biochemie, Brussels, Belgium Stanley, P.E., Department of Clinical Pharmacology, The Queen Elizabeth Hospital, Woodville, South Australia 5011 Wallick, E.I., The Alberta Research Council, 11315 - 87 Ave., Edmonton, Alberta, Canada Weiss, J.F., University of Tennessee, Comparative Animal Research Laboratory, Oak Ridge, Tennessee 37830, U.S.A. Wiebe, L.I., Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada Wigfield, D.C., Department of Chemistry, Carleton University, Ottawa, Ontario, Canada xi Preface This volume contains the proceedings of the International Conference on Liquid Scintillation: Science and Technology held on June 14-17, 1976 at the Banff Centre in Alberta, Canada. A majority of the 70 delegates who attended the conference stayed in the accommodation provided on the Banff campus and enjoyed its beautiful setting in the heart of the Rocky Mountains. Despite the distracting surroundings, the conference program was full and intensive. Excel- lent plenary lectures were given by Drs. Horrocks, Ross, Gibson, and Stanley. Unfortunately, our fifth plenary lecturer, Mr. H.A. Polach, was unable to attend the conference due to sudden illness. We missed both his presence and his news from the world of low background counting. Although liquid scintillation counting is a fairly mature technique, research papers were presented at the conference on a wide range of topics including not only old problems such as the counting of heterogenous samples, but also the counting of novel isotopes and bioluminescence. We would like to express our gratitude to Dr. C.T. Peng, Dr. E. Schräm, and Dr. P.E. Stanley, who together with members of the organizing committee chaired the research sessions. The idea of workshops or panel discussions on liquid scintillation counting introduced at the Sydney symposium in 1973 was expanded to two such ses- sions, one on instrumentation and one on sample preparation. Much of the credit for the lively discussions must be given to the panel members (Instrumen- tation: B.H. Laney—Chairman, J.E. Noakes, and P.E. Stanley. Sample prepara- tion: E.D. Bransome Jr., R. Ferris, W.E. Kisieleski, K. Painter—Chairman, C.T. Peng, and D.C. Wigfìeld) who presented the introductory workshop papers that are included in these proceedings. The ensuing discussion periods provided a forum for not only the further consideration of current problems but also infor- mal speculation into the future. For providing financial assistance the organizing committee would like to sincerely thank Searle Instrumentation, Packard Instrument Inc., Beckman In- struments Inc., and Terochem Laboratories. We are very grateful to both the Province of Alberta and the University of Alberta for also providing financial xiii PREFACE assistance. We offer our special thanks to Dr. MJ. Huston, Dean of the Faculty of Pharmacy and Pharmaceutical Sciences at the University of Alberta not only for assisting financially but also for allowing the conference to use the faculty secretarial staff. Also, from our faculty we would like to sincerely thank the Associate Dean, Dr. G.E. Myers, for initiating the conference proceedings. For their guidance in the initial planning stages and their support through- out, we thank the members of the Scientific Advisory Committee (S. Apelgot, J.B. Birks, C.T. Peng, H.H. Ross, E. Schräm, and P.E. Stanley). We are sure that all the conference delegates would like to express their appreciation to the staff and management of the Banff Centre, and to Mr. Bob Sandford of the National Parks interpretive program who gave us an entertaining and enlightening talk about Banff. Also, in a lighter vein we compliment Dr. H.H. Ross who is not only an expert in Cerenkov counting but also exhibited great talent as a chef at our barbecue. This pleasantly informal occasion allowed an opportunity to greet old friends and make new ones. Finally, we must express our gratitude to those people behind the scenes. Mr. J. Mercer, who helped with the lighting at the conference, and Mr. S. McQuarrie, who not only helped with the audio visual equipment but also has made a great contribution in proofreading and indexing the proceedings. Our secretaries, Bev Johnson and Pearl Metke, also deserve our sincerest thanks for their invaluable help, both during and after the conference. A.A. Noujaim C. Ediss L.I. Wiebe XIV The Mechanisms of the Liquid Scintillation Process by Donald L. Horrocks Scientific Instruments Division Beckman Instruments Inc. Irvine, California 92713 The liquid scintillation process is based upon the conversion of part of the kinetic energy of an ionizing particle (usually from the decay of a radionuclide) into photons. These photons are collected and measured by multiplier phototubes (MPTs) and subsequently, the pulses from the MPTs are summed, sorted, and counted. Initially, the liquid scintillation process was used only as a means of detecting and quantitating the amount of radionuclide present in a sample. However, in recent years, there have been more and more applications involving not only the detection and quantitating, but also the measure of the distribution of the amplitudes of pulses produced by the interaction of the radiations with the liquid scintillators. Since the pulse amplitude can be calibrated with the energy of the radiations, it is possible to measure more than one radionuclide in a sample by selection of the pulse amplitudes emanating from the different radionuclides. Figure 1 shows a pulse height spectrum of a sample of thorium showing the presence of several radionuclides which can be identified by the differ­ ent pulse amplitudes produced in the liquid scintillator. In the history of liquid scintillation, it seems as though the number of "users" of liquid scintillators has increased at a tremendous rate. However, as is the case with many analytical methods, many "users" do not totally appreciate the complexity of the liquid scintillation process and as a result, often misinterpret results or attempt experiments which are beyond the capability of the method. In this paper, it will be attempted to discuss the many mechanisms which comprise the "liquid scintillation process". It is hoped that an understanding of the mechanisms will help the many "users" to obtain more meaningful and accurate data from their experiments. 1 DONALD L. HORROCKS 7 \ (A) 6 Ì 5, • 4 1 -i 1 (C) 1 3 (D) 1 2 - * (E) \ I l\ i 1 \ ( B ) 1 1 L 50 100 150 PULSE HEIGHT DIFFERENTIAL PULSE HEIGHT SPECTRUM FOR Th 232, Th228, AND DAUGHTERS PLUS A SMALL AMOUNT OF Th230. Figure 1. Pulse height spectrum of Thorium sample dissolved in a liquid scinti l lat ion solution. 2