105 10« 103 102 101 10 HT17 1 3$ ' 5 1U S ' 36 ' 5 1 55 ' H6 ' 5B 1 35 1 35 ' 49 ' 1 24 23 26 13 1 38 13 22 4 6 31 27 25 LflB. CODE NO. TECHNICAL REPORTS SERIES No. Elemental Analysis of Biological Materials Current Problems and Techniques with Special Reference to Trace Elements The cover picture illustrates the lack of agreement between different analytical laboratories in reporting the concentration of cobalt in an IAEA intercomparison material, animal muscle H-4. Each point represents the mean value reported by one laboratory (points with downward pointing arrows represent limits of detection). These results have been arranged from left to right of the figure in order of increasing value. The different symbols represent different analytical techniques. See chapter 15 for further results of this kind. ELEMENTAL ANALYSIS OF BIOLOGICAL MATERIALS Current Problems and Techniques with Special Reference to Trace Elements The following States are Members of the International Atomic Energy Agency: AFGHANISTAN HOLY SEE PHILIPPINES ALBANIA HUNGARY POLAND ALGERIA ICELAND PORTUGAL ARGENTINA INDIA QATAR AUSTRALIA INDONESIA ROMANIA AUSTRIA IRAN SAUDI ARABIA BANGLADESH IRAQ SENEGAL BELGIUM IRELAND SIERRA LEONE BOLIVIA ISRAEL SINGAPORE BRAZIL ITALY SOUTH AFRICA BULGARIA IVORY COAST SPAIN BURMA JAMAICA SRI LANKA BYELORUSSIAN SOVIET JAPAN SUDAN SOCIALIST REPUBLIC JORDAN SWEDEN CANADA KENYA SWITZERLAND CHILE KOREA, REPUBLIC OF SYRIAN ARAB REPUBLIC COLOMBIA KUWAIT THAILAND COSTA RICA LEBANON TUNISIA CUBA LIBERIA TURKEY CYPRUS LIBYAN ARAB JAMAHIRIYA UGANDA CZECHOSLOVAKIA LIECHTENSTEIN UKRAINIAN SOVIET SOCIALIST DEMOCRATIC KAMPUCHEA LUXEMBOURG REPUBLIC DEMOCRATIC PEOPLE'S MADAGASCAR UNION OF SOVIET SOCIALIST REPUBLIC OF KOREA MALAYSIA REPUBLICS DENMARK MALI UNITED ARAB EMIRATES DOMINICAN REPUBLIC MAURITIUS UNITED KINGDOM OF GREAT ECUADOR MEXICO BRITAIN AND NORTHERN EGYPT MONACO IRELAND EL SALVADOR MONGOLIA UNITED REPUBLIC OF ETHIOPIA MOROCCO CAMEROON FINLAND NETHERLANDS UNITED REPUBLIC OF FRANCE NEW ZEALAND TANZANIA GABON NICARAGUA UNITED STATES OF AMERICA GERMAN DEMOCRATIC REPUBLIC NIGER URUGUAY GERMANY, FEDERAL REPUBLIC OF NIGERIA VENEZUELA GHANA NORWAY VIET NAM GREECE PAKISTAN YUGOSLAVIA GUATEMALA PANAMA ZAIRE HAITI PARAGUAY ZAMBIA PERU The Agency's Statute was approved on 23 October 1956 by the Conference on the Statute of the IAEA held at United Nations Headquarters, New York; it entered into force on 29 July 1957. The Headquarters of the Agency are situated in Vienna. Its principal objective is "to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world". (C) IAEA, 1980 Permission to reproduce or translate the information contained in this publication may be obtained by writing to the International Atomic Energy Agency, Wagramerstrasse 5, P.O. Box 100, A-1400 Vienna, Austria. Printed by the IAEA in Austria February 1980 TECHNICAL REPORTS SERIES No. 197 ELEMENTAL ANALYSIS OF BIOLOGICAL MATERIALS Current Problems and Techniques with Special Reference to Trace Elements INTERNATIONAL ATOMIC ENERGY AGENCY VIENNA, 1980 ELEMENTAL ANALYSIS OF BIOLOGICAL MATERIALS: CURRENT PROBLEMS AND TECHNIQUES WITH SPECIAL REFERENCE TO TRACE ELEMENTS IAEA, VIENNA, 1980 STI/DOC/lO/197 ISBN 92-0-115080-6 FOREWORD Nuclear techniques, particularly activation analysis, are already extensively used for the in-vitro assay of trace and minor elements in biological materials. The International Atomic Energy Agency has, for many years, promoted their application in the medical, environmental and agricultural sciences, and has also assisted such work by the provision of analytical quality control services. However, no single trace analysis technique can be considered best for all purposes, and it is therefore natural that the IAEA has also taken an interest in recent developments in other, non-nuclear, trace analysis techniques. This interest, stimulated by the recommendations of a WHO Expert Committee meeting in Geneva, 1973, which pointed to the need for guidance on the selection of optimal methods of analysis, led to the convening of an IAEA Advisory Group meeting in December 1976 to consider this subject and to draw up recommendations on actions to be taken. The principal recommendation was that a report be produced containing a comparative review of selected techniques for the assay of trace and minor elements in biological materials, together with other relevant information on the need for such analyses, sampling, sample preparation and analytical quality control. The present publication is the outcome of this work. The chapters on 'techniques' (chapters 7—13) have in the meantime been presented as review papers at an IAEA Symposium on Nuclear Activation Techniques in the Life Sciences, held in Vienna in 1978, at which one of the themes was the comparison of neutron activation analysis with other trace analysis techniques. The full texts of the review papers were withheld from publication in the proceedings so that they might be revised as an integral part of the present monograph, which thus constitutes a companion volume to the symposium proceedings. While it is not practicable to consider all possible trace analysis techniques within the scope of a monograph of this kind, most of the major analytical techniques currently in widespread use are included. It is therefore hoped that the volume will be a valuable aid to analysts who wish to identify suitable analytical techniques for the determination of trace and minor elements in biological matrices. Moreover, since each of the chapters on 'techniques' considers their applicability to the elemental assay of an identical group of biological reference materials, the information provided enables the reader to compare these techniques on a uniform basis. The IAEA wishes to express its gratitude to all those who have taken an active interest in this publication and especially to those who have contributed directly to the contents. The views expressed are those of the authors, and are not necessarily shared by the IAEA. CONTENTS ON THE NEED FOR TRACE ELEMENT ANALYSES IN THE LIFE SCIENCES 1. The need for trace element analyses in the animal sciences 3 G. Pethes 2. The need for trace element analyses in the medical sciences 19 KM. Hambidge 3. The need for more information on the trace element content of foods for improving human nutrition 29 N. Rao Maturu 4. The need for trace element analyses of biological materials in the environmental sciences 39 E.I. Hamilton SAMPLING AND SAMPLE PREPARATION FOR TRACE ELEMENT ANALYSIS 5. Sampling and storage of biological materials for trace element analysis 57 B. Sansoni and G. V. Iyengar 6. Sample preparation of biological materials for trace element analysis 73 G. V. Iyengar and B. Sansoni ANALYTICAL TECHNIQUES FOR TRACE AND MINOR ELEMENTS IN BIOLOGICAL MATERIALS 7. Neutron activation analysis 105 V.P. Guinn and J. Hoste 8. Atomic absorption spectroscopy 141 G.F. Kirkbright 9. Inductively coupled plasma atomic emission spectroscopy 167 W.J. Haas and V.A. Fassel 10. Mass spectrometry 201 G. H. Morrison 11. X-ray methods 231 A.A. Katsanos 12. Chemical methods 253 R. Neeb 13. Electrochemical methods 281 R. Neeb ANALYTICAL QUALITY CONTROL 14. The chemical laboratory and trace element analysis 303 E. I. Hamilton 15. Reference samples for trace elements in biological materials and associated analytical problems 317 L. Kosta APPENDICES I Elemental compositions of four selected reference materials 349 II The applicability of some selected analytical techniques to the assay of trace and minor elements in four biological reference materials 351 List of Contributors 369 ON THE NEED FOR TRACE ELEMENT ANALYSES IN THE LIFE SCIENCES Chapter 1 THE NEED FOR TRACE ELEMENT ANALYSES IN THE ANIMAL SCIENCES G. PETHES 1. INTRODUCTION The advent of new, sensitive, and in some cases automated, methods of analysis for trace and mineral elements in biological materials, together with the fact that, in the last 30 years, some 9 new elements have been added to the list of known essential trace elements, have resulted in an almost explosive growth in the literature on this subject. Research on the biological role of trace elements can thus be regarded as a well-established scientific endeavour. The purpose of this chapter is to review briefly some of the more pertinent findings as regards the role of trace elements in the animal sciences, and to draw attention to some of the ways in which analyses of trace elements can add to our understanding of these matters. The elementary constituents of human and animal organisms may be classi- fied as major and trace elements, the latter group comprising both essential and non-essential elements (including toxic elements). The problems outlined in this chapter are restricted to those involving trace elements already proven to be essential for optimal animal production. No attempt is made in this chapter to refer to individual authors since it would not be practicable to cover the literature exhaustively here, and a selective list of specific references would be invidious. However, a list of general references is appended, in which almost all the data referred to in this chapter may be found [1-24]. 2. GENERAL CONSIDERATIONS For the purpose of this review, the essential trace elements are taken to be those for which a lower than normal intake results in a decreased growth rate, production or fertility, and hence affects animal production. Workers in animal health and production naturally focus their attention on these