Nucleonics W. S. Lyon and H. H. Ross’ Analytical Chemistry Division, Oak Ridge National Laboratory,’ Post Office Box X, Oak Ridge, Tenn. 37830
Although the journals continue to be filled with papers describing application of nuclear techniques to many problems, we have found little that is original or innovative during our report period (November 1973-November 1975). Originality, like beauty, may well lie in the eye of the beholder and, if so, some may accuse us of looking with a jaundiced eye. The reviews, bibliographies, books, etc. listed in our Tables I to IV, however, will offer the reader himself an ample opportunity to explore in depth the accomplishments of the past several years. The precision and accuracy of our own analytical capabilities is too coarse to permit us to measure differences in the slight amount of originality found in most of these papers. This should not be construed as derogatory to the current literature; rather, it reflects the increasing emphasis on application and “data accumulation” as opposed to basic research and free investigation. For a number of years, the field of nucleonics has been filled with solutions looking for problems. Courtship has now been followed by marriage; and from many of these unions, offsprings of data have come to assist researchers in energy, environmental, and medical studies. One hopes that some of these progeny will also be innovative techni ues to solve future problems. We discuss briefly below trenls as we see them and also point out several new areas of interest and potential. Radiotracers. Isotope applications are still declining, with the exception of medical applications (immunoassay, for example). Concern is now more with measuring radioactivity in the environment than using it. Plutonium has received a very bad press, and there have been a number of papers concerned with the hazards of P u and, of more interest to us, methods of separating and assaying Pu and other transuranics in the environment (86-91). The use of I4C counting for dating still presents some problems as evidenced by a number of papers, typical of which are a critical review (92) and a discussion of errors due to possible enrichment of 14C a t high altitudes (93). Papers describing and apparently refuting the hypothesis that neutrons are generated by lightning and thus contribute to 14C anomalies were summarized in short discussion (94).
Activation Analysis. Applications of neutron and charged particle activation analysis to environmental problems continue to proliferate. Air particulates, soil, vegetation, coal and fly ash have drawn the lion’s share of attention. Ion induced x-ray fluorescence (95-97) has been highly touted and, of course, x-ray fluorescence induced by tube and radioisotope sources continues to gain in popularity as a relatively inexpensive multielement technique (98). Comparisons with NAA (99), development of a background reduction method ( l o o ) , and attempts to use XRF for difficult elemental analyses such as S (101), are some of the more interesting studies reported. No discussion of multielement techniques can be complete without a very appreciative bow to the National Bureau of Standards whose standards of orchard leaves, coal, fly ash, and bovine liver have played such an important part in testing and proving the validity of these methods. All analytical chemists owe the NBS a very special debt of gratitude for preparing and certifying these standards. Almost every paper discussing significant results from multielement analysis uses one or more of these standards to support its credulity. Those of us in XRF and NAA are especially indebted to the staff at NBS; without them, we literally wouldn’t know how good we are. The Oak Ridge National Laboratory is operated by the Union Carbide Corporation under contract with the US. Energy Research and Development Administration. 96R
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Ge(Li) Spectrometry. The Ge(Li) detector continues to be the single most important item in radioactivity measurement. A great number of papers describe applications and improvements in detectors; others discuss calibration, sources of error, etc. The Ge(Li) system is gaining new popularity for lowlevel application, such as radioenvironmental analyses (102), and at least one report shows Ge(Li) to be preferred over NaI(T1) for very low intensity samples (103). In studies concerning the detector itself, papers have discussed summation (104), peak position variation with geometry (105), and semi-empirical efficiency equations (106). This last is but one of a number of such efforts. A gamma-ray position-sensitive coaxial Ge(Li) detector has been developed . (107) . . in. which position is determined by geometry and pulse timing. New Radiation Detection Svstems. If we mourn the passing of much of the creative phase in nucleonics, we must surely rejoice in recognizing its brightest star-radiation detection. In no recent report period have we observed the profusion and diversity of new detector concepts. The ractical application of many of these detectors remains to e demonstrated. However, it is clear that a major thrust is being made a t both the problems of radiation detection and position localization. Regular readers of Analytical Chemistry are aware of the rediscovery of the opto-acoustic phenomenon originally demonstrated by Alexander Graham Bell. It was with some degree of surprise that we discovered two papers that deal with the analogous acoustic detection of radiation (108, 109). The detection is said to operate through amplification of the acoustic wave by a drift field within a solid. A subsequent damping of the wave generates a charge that can be collected in the usual way. One paper postulates the detection of a single y-ray event! A suggested application area is the search for superheavy elements among the primary cosmic rays. Two new detectors composed of liquids have also been described. In one (110), the detector is a cholesteric liquid crystal. Beams of ionizing particles are detected by the temperature change induced in the liquid. The second detector (111) consists of a cell containing a polar liquid positioned between two crossed polarizers. A light beam is directed on the cell and the polarizers are adjusted for maximum extinction of light. Local birefringence developed by ionizing radiation causes light to be transmitted through the cell to a conventional light detector. One of the most active areas of optical spectroscopy is the development of charge coupled or charge injection devices as two-dimensional array detectors. Ionizing radiation detection has been described in what must be a closely related device (112). The detector consists of an array of coupled conductor-insulator-semiconductor cells on a common substrate. Charge, developed by ionizing radiation, is repeatedly transferred within the device before being injected into the substrate where an electrical signal is developed. Position localization seems an obvious application. Other new detection systems have specifically addressed the task of radiation localization. Thus, a “needle array chamber”, based on gaseous multiplication, claims x-y response as its major feature (113). Each needle in the array behaves as an individual proportional counter. Very high count rates can be tolerated. A new position-determining scintillator is based on time resolution (114). Position accuracy is about 1 cm out of an area of -1 m2 for reasonably shaped systems. Additional detectors in the developmental stage include the use of HgI2 crystals for y- and x-ray detection (115117) and CaFz scintillator crystals for tritium detection
E
Harley H. Row (left) is Head of the instrumentation and Advanced Methodology Group in the Analytical Chemistry Division, Oak Ridge National Laboratory. A native of Illinois, he received his B.S. degree in chemistry from the University of Illinois in Urbana. His graduate Work was carried out at Wayne State University, Detroit, where he received his M.S. in 1958 and Ph.D. in analytical radiochemistry in 1960. In June 1960, Dr. Ross joined the staff of the Special Training Division of the Oak Ridge Institute of Nuclear Studies (now ORAU), where he was a lecturer in the Institute's courses in the techniques of using radioisotopes. In 1962 he left the Institute to-accept a position in the Nuclear Radiochemical Group at ORNL, which he held until 1972. Although Dr. Ross is no longer involved directly wlth the nucleonics activities of the Analytical Chemistry Division, he continues to m a i n p h a n interest and a research effort in both liquid scintillation spectroscopy and the application of radioisotopes to the solution of analytical problems. in 1967 he was given an IR-100 award for the development of the radioisotopic light source phctometer. W. S. Lyon (right) is Head of the Nuclear and Physics Methods Group of the Analytical Chemistry Division, Oak Ridge National Laboratory. He has been associated with the nuclear energy field since 1944 and has been at ORNL since 1947. He is a graduate of the University of Virginia and has done graduate work at the University of Tennessee in both chemistry and industrial management. receiving a master's degree in the latter in 1968. His main interests have been in nuclear nieasurements, decay scheme studies, and activation analysis. He has published over 90 papers on these subjects. He is the Editor of "Guide to Activation Analysis" (Van Nostrand; 1964). an associate editor of Radiochemical and Radiohalflical Letters and Regional Editor of the Journal of Radioanalytical Chemistty. He is actively pursuing standardization through committee work in the ASTM, USASi. NCRP, and the APHA.
(118). Finally, recent work has shown that several new gas mixtures show promise for neutron detectors when used in near-infrared and ultraviolet gas proportional scintillation counters (119).Such detectors can be used where fast energy response and good energy resolution are desired. The more developed areas of nucleonics continue to mature in a less dramatic way. An excellent reference (120) presents an overview of the current status of many of these topics. Discussions of internal gas counting, liquid scintillation counting, semiconductor detectors, nuclide standards, low level measurements, source preparation, calibration, and analytical applications are covered in detail. Some other specific reports that we have found to be of general interest include work in liquid scintillation counting (121129), Cerenkov counting (130), gas proportional counting (131), scattering (132, 133), radiorelease (134), and counting error analysis (135). Track Etch Techniques. Even the most casual reader of the scientific literature is quick to recognize that "hot" research areas follow a fashion as kaleidoscopic as the automobile styling of Detroit. For example, over the past ten years we have seen the rise and partial decline of such techniques as isotope dilution and exchange, radiometric titrations, kryptonate applications, substoichiometry, radiation scattering, and automated radiochemical separations. The fashion phenomenon is certainly not limited to nucleonics; virtually every scientific speciality has its own current persona grata. In the radioanalytical area, the run-away favorite for the current review period is the development and application of the track-etch technique. Our first analytical observation of this process was in 1967 where it was used to determine the microstructure distribution and total concentration of boron in other metals; in the past two-year period, we have noted more than 250 track-etch references! The primary application area naturally deals with the analysis of a-emitting nuclides. Recent reports describe the analysis of uranium in water (136, 137) and uranium ores (138). Major emphasis is given to sample preparation and concentration evaluation. The method has also been used for the determination of radon-222 in air (139) and radium-226 (140). Here, one notes that the number of tracks per unit detector area is the most common experimental parameter that is determined. However, other track parameters such as length, density, and direction can be used to advantage. Some of these effects are characterized in a report dealing with the analysis of fissile-material solutions (141). Being insensitive to high doses of light-charged particles, y rays, and other electromagnetic radiations, track detectors are suitable to low-level-a counting. Tests have been carried out on a number of materials; their track reg-
Table I. Books Ref.
Title Analytical Chemistry of Neptunium Analytical Chemistry of Selenium and Tellurium Applications of Liquid Scintillation Counting Basic Science Principles of Nuclear Medicine Bioassay Techniques and Environmental Chemistry Characterization of Solid Surfaces Comprehensive Inorganic Chemistry Instrumentation in Nuclear Medicine Introduction to Liquid Scintillation Counting Introduction to Liquid Scintillation Counting Nuclear Analytical Chemistry. I1 Nuclear Analytical Chemistry. I11 Nuclear Electronics Nukleare Elektronik (Nuclear Electronics) Nuclear Spectroscopy and Reactions Plutonium. A General Survey Radioactivity and Radiation Detection Radioassay in Clinical Medicine Radiochemistry Radioecology Tritium Toxicity of Plutonium Users' Guides for Radioactivity Standards
Comment Gen. chem. and anal. info Wide variety anal. techniques Theory included Fundamental info. in 9 chap. Five sect. stress principles Exhaustive rept. Radioelements included Recent develop. surveyed Useful as a beginning text Tracer methodology included Extension of previous work Ibid. General review Signal handling emphasized Tables and text Exhaustive treatment Summary of theory and practice Mainly of biological interest Collection of reviews Translation from the Russian Massive coverage 43 pages of critical information Elements treated separately ANALYTICAL CHEMISTRY, VOL. 48, NO. 5, APRIL 1976
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Table 11. Bibliographies and Reviews Bibliographies
Ref. (24) (25) (26) (27) (28)
Comments 54 PP 71 PP 43 pp, 190 Ref. 57 pp, 244 Ref. 183 pp, 872 Ref.
Topic Archaeological applications Ecological applications Traces in soil and agric. Track etch fission Track etch general
Reviews 4-7r ion chamber Measurement of Activity
All are reviews from Herceg-NoviInternational Summer School
Proportional counter pulses Thin source prep. Semi-conductor detection Radioanal. chem. Radiochromatography Radioelectrochemistry Radioisotopes in chem. Tracer methods
Historical review State of art summary Survey Emphasizes nuclear data Chapter on appl. to reaction mechanisms
Archeology Environmental General Forensic Forensic Photon
In Spanish Reactor, source, acceler. appl. 20-page review Short genl review 30-page review Includes useful data tables
Actinide detn in fuels Comparison of techniques Compilation of radiochem. proc. Detn radionucl. in H20 Radiochem. methods Radiochem. sepns Radioisotope prod. Environ. rad. assessment 85Kr: Instrum. for measure. Nuclear medicine radiochemistry Tritium instrumentation Whole body counting
Sepn and measurements 9 techniques for H2O pollutants Argonne Lab Water pollution handbook Russian Italian French Techniques and requirements Environ. monitoring Role of chemist Environ. monitoring Developments since 1965
Liquid scint. cting: afterpulses Liquid scint. cting: mechanisms Liquid scint. cting: status Liquid scint. cting: 3H, I4C Liquid scint. cting: Cerenkov
Herceg-Novi paper Herceg-Novi paper Herceg-Novi paper German General review
Nuclear safeguards Nucl. tech. in environ. Nucl. and Radiochem. in environ. Radioisotope gauges Radioisotopes in on-stream anal. RadioisotoDes in on-stream anal.
From Nucleonics Week Isotope techniques German Polish equipment Australian appl. Historical review
Isotope Applications
Table 111. Proceedings of Conferences Ref. (68) (69) (70) (71) (72) (73) (74) (75) (76) (77) (78) (79) 98R
Topic Environ. surveillance Liq. scint. counting Small accelerators Radionuclide metrology Isotope techniques in groundwater hydrology Scintillation counting Nuclear medicine Food and environmental contamination Nuclear data XXIV Congress of IUPAC Nucl. photography and track etching Nucl. methods in environ. res.
Location Warsaw, Poland Brighton, England Denton, Texas Herceg-Novi, Yugoslavia Vienna, Austria Washington, D.C. Miami, Fla. Otaniemi, Finland Paris, France Hamburg, Germany Bucharest, Rumania Columbia, Mo.
ANALYTICAL CHEMISTRY, VOL. 48, NO. 5, APRIL 1976
Comments IAEA Proc., Vol. 1and 2 28 papers Applications Excellent reviews IAEA Proc., Vol. 1and 2 21st Annual Meeting Prod., meas. radioisotopes IAEA Proc. IAEA Proc., Vol. 1 and 2 Radiochemistry In several languages, Vol. 1and 2 43 papers
T a b l e IV. Aids Ref.
Topic
(80)
NAA tables
(82) (82)
y - r a y spectra y - r a y tables
(83) (84)
y-ray tables
(85)
A c t i v a t i o n a n d decay tables
Nuclear activation
Comment u's, y's, satur. factors Heath's catalog 7's f r o m (n,2n), (n,p), h a ) , (n,n'), (n,d) y's as f u n c t i o n o f energy u's f o r n,p,y reactions
B'S
tllz's, y energies a n d intensities ~
istration properties are described (142). A somewhat different application is the determination of nitrogen in biological materials carried out a t the National Bureau of Standards (143). Determinations were made on orchard leaves and bovine liver. General overviews of the analytical application of track techniques are available (144,145). Lest the reader think that all of the action is in application, rest assured that experimental methodology is keeping pace. The major facets of research work in this area are materials development, track stability, etching technology, and improved readout techniques. Common materials used as the track detector include cellulose acetates (146-149), and cellulose nitrate (150-152). Some of the less common substrates that have been employed are celluloid (153), mica and quartz (154),glass (155), and Kodak Special Film LR115 (156). In each case, advantages and disadvantages are evaluated for a particular application. The latent track fading characteristics of plastic materials have been studied (157, 158) along with the influence of high doses of y rays (159). After detector exposure, a carefully controlled etching procedure is usually required. The quality of the track registration is a strong function of this process. New and conventional etching methods have been discussed (155, 160162), and insights into the fundamental mechanisms of the
LITERATURE CITED (1) Mikhailov, V. A,, Ed., "Analytical Chemistry of Neptunium", John Wiley and Sons, New York, N.Y.. 1973. (2) Nazarenko, I. I., Ermakov, A. N., Ed., "Analytical Chemistry of Selenium and Tellurium", John Wiley and Sons, New York, N.Y., 1972. (3) Horrocks, D. L., Ed.. "Applications of Liquid Scintillation Counting", Academic Press, Inc., New York, N.Y.. 1974. (4) Boyd, C. M., Dalrymple, G. V., Ed., "Basic Science Principles of Nuclear Medicine", C. V. Mosby Company, St. Louis, Mo., 1974. (5) Glass, G. E., Ed., "Bioassay Techniques and Environmental Chemistry", Ann Arbor Science Publishers, Inc., Ann Arbor, Mich., 1973. (6) Kane, P. F.. Larrabee. G. B., Ed., "Characterization of Solid Surfaces", Plenum Publishing Corp., New York, N.Y., 1974. (7) Trotman-Dickenson, A. F., Ed.. "Comprehensive Inorganic Chemistry, Volume 2". Pergamon Press Ltd., Oxford, 1973. (8)Hine, G. J., Sorenson, J. A,, Ed., "lnstrumentation in Nuclear Medicine. Volume 2", Academic Press, Inc., New York, N.Y.. 1974. (9) Dyer, A., Ed.. "Introduction to Liquid Scintillation Counting". Heyden and Son Ltd., London, 1974. (10) Neame, K. D., Homeoood, C. Q . , Ed., "lntroduction to Liquid Scintillation Counting", Butterworth. London, 1974. (11) Toelgyessy, J., Varga, S., Ed., "Nuclear Analytical Chemistry. Ii", Publishing House of the Slovak Academy of Sciences, Bratislava, 1972. (12) Toelgyessy, J., Varga, S. Ed.. "Nuclear Analytical Chemistry. Ill", Publishing House of the Slovak Academy of Sciences, Bratislava, 1974. (13) Nicholson, P. W., Ed., "Nuclear Electronics", John Wiley and Sons, Inc., London, 1974. (14) Abend. K., Vogelsang, E., Ed., "Nukleare Elektronis (Nuclear Electronics)", Thiemig, Munich, 1973. (15) Cerny, J.. Ed., "Nuclear Spectroscopy and Reactions. Part A". Academic Press, Inc., New York, N.Y.. 1974.
etching process have led to improved etch procedures. The final step in a track-etch analysis is the often tedious track readout. Here, one usually resorts to a microscope examination or photographic process to "blow up" the track substrate. Recently, attention has been directed to various instrumental (and perhaps automatic) methods of readout. We have noted investigations that explore the use of a flying spot scanner (163) and a vidicon tube (164).A patent has also been granted on an optical system using visible light transmission (165). The electro-optical detectors are usually coupled to the track detector throu h a microscope. Automatic computer processing of the h t a appears feasible. I t is clear that any improvement in readout capability will be a major advance in the application of the track-etch technique. As noted previously, the work in this area is prodigious; in the lexicon of the track-etch scientist, our discussion only scratches the surface. Unusual Items. Last time we mentioned the anomalous U isotope ratios found in Gabon and the possibility of a fission event having occurred there; this seems now established (166). The anomalous zo6Pb/207Pbratios in radiohalos found in geologic samples now present a problem for nucleosynthesis (167). In-vivo nuclear fission of 235Uin man has been suggested as one cause of decompression sickness in deep-sea divers (168).We would also like to report that the search for elusive and unknown a-emitters in nature (169) and for radioactive silver in uranium ore (170) has failed to produce even the hint of a positive result. And finally, in line with our policy of keeping readers informed on the latest psychological and medical reports concerning our work, we present the comment of a professor of biology from Indiana University (171). He states, based on studies of crime rates, that radiation from nuclear power plants appears likely to be "a substantial underlying cause of crimes of violence." So if you kick the kids around toni h t and punch your wife, blame it on s5K (for kick) and 23 P u (for punch). And think how useful the ubiquitous 41A will be to the Music Man as he sings of his wish for "Hester to win just one more A." Not to mention the rest of us!
f
(16) Taube, M., Ed., "Plutonium. A General Survey", Verlag Chemi GmbH, Weinheim, 1974. (17) Miller, D. G., Ed., "Radioactivity and Radiation Detection", Gordon and Breach, Science Publishers, inc.. New York, N.Y., 1972. (18) Newton, W. T., Donati. R. M., Ed., "Radioassay in Clinical Medicine", Charles C Thomas, Publishers, Springfield, Ill., 1974. (19) Maddock, A. G., Ed., "Radiochemistry", Butterworths, London, 1975. (20) Klechkovskii, V. M., Polikarpov. G. G.. Aleksakhin, R. M., Ed., "Radioecology", John Wiley and Sons, Inc., New York, N.Y.. 1973. (21) Moghissi, A. A,, Ed., "Tritium", Messenger Graphics, Publishers, Las Vegas, N.M., 1973. (22) "Toxicity of Plutonium", Medical Research Council, London, England, 1975. (23) "Users' Guides for Radioactivity Standards", National Academy of Sciences-National Research Council, Washington, D.C., 1974. (24) Schultz, S. L., Schultz. V. (TID-3920), (ERDA Technical Information Center, Oak Ridge, Tenn.), NTIS, Springfield, Va., 1975. (25) Schultz, V. (RLO-2213) (Suppl. 2), (Washington State University, Pullman, Wash.), NTIS, Springfield, Va.. 1975. (26) "Tracer Techniques (1974-1967)", Slough, Engl., Commonwealth and Agricultural Bureaux (Feb. 1975), 1975. (27) Newland, E. A. (AAEC/LIB/Bib-368), (Australian Atomic Energy Commission Research Establishment, Lucas Heights), NTIS, Springfield, Va., 1972. (28) Griffith, R . V. (UCRL-51568), (California University, Livermore (USA), Lawrence Livermore Lab), NTIS, Springfield, Va., 1974. (29) Weiss. H. M., Nucl. lnstrum. Methods, 112,291 (1973. (30) Spernol, A., Nucl. Instrum. Methods. 112, 23 (1973). (31) Campion, P. J., Nucl. Instrum. Methods, 112, 75 (1973). (32) van der Eijk, W., Oldenhof, W., Zehner, W., Nucl. Instrum. Methods, 112, 343 (1973). (33) Bertolini, G., Cappellani, F.. Restelli, G., Nucl. Instrum. Methods, 112, 219 (1973).
(34) Szabadvarv, F.. J. Radioanal. Chem., 20, 745 (1974). (35) Prydz, S.,Anal. Chem., 45, 3217 (1973). (36) Raaen, H. P., Anal. Chem., 46, 1265 (1974). (37) Gorski, L., "Nuclear Data in Science and Technology", Vol. 1, Vienna, IAEA, 1973, p 377. (38) Raaen, V. F., "Investigation of Rates and Mechanisms of Reactions", Part 1, John Wiley and Sons, Inc., New York, 1974, p 257. (39) Travesi, A,, Energ. Nucl. (Madrid), 18, 239 ( 1974). (40) Filby, R. H., Shah, K. R.. Toxical Environ. Chem. Rev., 2, 1 (1974). (41) op de Beeck. J.. Hoste, J., Analyst (London), 99, 973 (1974). (42) Gangadharan, S., Sci. Today (Bombay), 8, 54 (1974). (43) Guinn, V. P., Annu. Rev. Nucl. Sci., 24, 561 (1974). (44) Kosta, L., Dermelj. M.. Slunecko, J., Pure Appl. Chem., 37, 249 (1974). (45) Wenzel, U., Herz. D., J. Radioanal. Chem., 21, 473 (1974). (46) Coleman, R. F., Anal. Chem., 46, 989A (1974). (47) Flynn, K. (ANL-75-24), NTIS, Springfield, Va., 1975. (48) Kahn, B., Water Water follut. Hsndb., 4, 1357 (1973). (49) Ghersini, G., Energ. Nucl. (Milan), 20, 461 (1973). (50) Billmovich, G. N., Usp. Anal. Khim., 1974, 105. (51) Baudin, G.. Bull. Inform. Sei. Tech. (Paris), 186, 43 (1974). (52) Peters C. W., Trans. Nucl. Sei., 21, 470 (1974). (53) Budnitz. R. J. (LBL-1779), (California University, Berkeley, Lawrence Berkeley Lab), NTIS, Springfield, Va., 1973. (54) Subramanian. G.. Semin. Nucl. Med., 4, 219 (1974). (55) Budnitz, R. J., Health Phys., 26, 165 (1974). (56) Cohn, S. H., Palmer, H. E., lnt. J. Nucl.
ANALYTICAL CHEMISTRY, VOL. 48, NO. 5, APRIL 1976
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Med. Blol., 1, 155 (1974). (57) Williams, A,, Smith, D., Nucl. Instrum. Methods, 112, 131 (1973). (58)Klein, J.. Nucl. Instrum. Methods. 112, 117(1973). (59) Stanef, I., Nucl. Instrum. Methods, 112, 111 (1973). (60) Jordan, P., Buechler, E., May, K., J. Radloanal. Chem., 14, 71 (1973). (61) Francois, E., lnt. J. Nucl. M.4. Blol., 1, 1 (1973). (62) "Nuclear Safeguards", McGraw-Hill, New York, 1974. (63) Whitley, J. E.. Trans. SOC. Occup. Med., 22, 126 (1972). (64) Lieser, K. H.. Radlochlm. Acta. 18, 115 (1972). (65) Wierzchowski, M.. aTechnical Meeting No. 8t4. Bassel, Nuclex, 1972. (66) Howarth, W. J., Wenk, G. J., Wilkinson, L. R., Can. Mining Met. Bull., 66, 76 (1973). (67) Wan, J. S., At. EnergyAust., 16, 3 (1973). (68) "Symposium on Environmental Surveillance Around Nuclear Installation," Warsaw, Poland, CONF-731117-2; SM-180143, 1972. (69) Crook, M. A,, Johnson, P., Ed., "Liquid Scintillation Counting," Heyden, London, 1974. (70) "3rd Conference on the Use of Small Accelerators," Denton, Texas, CONF-741040-13, NTIS, Springfield, Va., 1975. (71) "Proceedings of 1st International Summer School on Radionuclide Metrology", Aug. 21Sept. 1, 1972, Herceg-Novi. Yugoslavia, Nucl. lnstrum. Methods, 112, No. 1-2, 1973. (72) "Isotope Techniques in Groundwater Hydrology. Volume I and 2", IAEA, Vienna, Austria, 1974. (73) "14th Scintillation and Semiconductor Counter Symposium", /E€€ Trans Nucl. Sci., NS22, No. 1, 1975. (74) Ashkar, F., Miale. A,, Jr., Smoak, W., Ed., "Study Guide in Nuclear Medicine", Charles C Thomas, Publisher, Springfield, Ill., 1972. (75) "Comparative Studies of Food and Environmental Contamination", IAEA, Vienna, Austria, 1974. (76) "Nuclear Data in Science and Technology, Vol. 1 and 2", IAEA Vienna, Austria, 1973. (77) "Twenty-Fourth International Congress of Pure and Applied Chemistry'', Vol. 6, Radiochemistry IUPAC, Butterworths, London, 1974. (78) Nicolae, M., Ed., "Proceedings of the 8th International Conference on Nuclear Photography and Solid State Track Detectors, Vol. 1 and 2", lnstitutul de Fizica Atomica, Bucharest, Romania, 1972. (79) Vogt, J. R.. Meyer. W., Ed., "Nuclear Methods in Environmental Research", CONF740701, University of Missouri, Columbia, Mo., 1975. (80) Leclerc, J. C., Cornu, A., Ed., "Neutron Activation Analysis Tables", Heyden, London, 1974. (81) Heath, R. L.. Ed., "Gamma-Ray Spectrum Catalog", 3rd ed., Vol. 1 and 2. ANCR-1000-2, NTIS, U S . Dept. of Commerce, Springfield, Va., 1975. (82) Lis, S. A,, J. Radioanal. Chem., 24, ( l ) , 125 (1975). (83) Lis, S. A.. J. Radioanal. Chem., 25, (1975). (84) "Handbook on Nuclear Activation CrossSection", Vienna: iAEA, 1974. (85) Bujdoso, E., Feher, I., Kardos, G., Ed., "Activation and Decay Tables of Radioisotopes", American Elsevier Publishing Company, Inc., New York, N.Y., 1973. (86) Reynolds, S. A,, Scott, T. G., Radiochem. Radioanal. Lett., 23, 269 (1975). (87) Scott, T. G., Reynolds, S.A,, Radiochem. Radioanal. Lett.. 23, 275 (1975). (88)Piltingsrud, H. V., Stencel, J. R.. Health Phys., 25, 448 (1973). (89) Sill, C. W., Puphai, K. W., Hindman, F. D., Anal. Chem., 46, 1725 (1 974). (90) Lefevre, H., Godement, A,, Radiochem. Radioanal. Left., 17, 197 (1974). (91) Bokowski, D. L., Am. lnd. Hyg. Assoc. J.,
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0
35, 333 (1974). (92) Renfrew, C.. Clark, R. M., Archaeometry, 16, 5 (1974). (93) Harkness, D. D., Burleigh, R., Archaeometry, 16, 121 (1974). (94) Lyon, W. S.,Radiochem. Radipanal. Lett., 21, 273 (1975). (95) Valkovic, V., Miljanic, D., Wheeler, R. M., Liebert. R. E.. Zabel, T.. Phillips, G. C.. Nature (London),243 (5409), 543 (1973). (96) Reuter, W., Lurio, A,, Cardone, F., Ziegler, J. F.. J. Appl. Phys., 46, 3194 (1975). (97) Pabst, W., Nucl. Instrum. Methods, 124, 143 (1975). (98) Kulkarni, P. V., Preiss, I. L., J. Radioanal. Chem., 24, 423 (1975). (99) Hammerle, R. H., Marsh, R . H., Rengan, K., Giauque, R. D., Jakievic, J. M.. Anal. Chem.,
45, 1939 (1973). (100) Dzubay, T. G., Jarrett. E. V., Jaklevic, J. M., Nucl. Instrum. Methods, 115, 297 (1974). (101) Dziunikowski, E., Radiochem. Radioanal. Lett., 16, 73 (1974). (102) Camp, D. C.. Gatrousis, C., Maynard, L. A,, Nucl. Instrum. Methods, 117, 189 (1974). (103) Robertson, R., Spyrou, N. M., Kennett, T. J., Anal. Chem., 47, 65 (1975). (104) de Bruin, M., Korthoven, P. J. M., Radiochem. Radioanal. Lett., 19, 153 (1974). (105) Helmer, R. G., Gehrke, R. J., Greenwood, R. C., Nucl. Instrum. Methods, 123, 51 (1975). (106) Hajnal, F., Klusek, C., Nucl. lnstrum. Methods, 122, 559 (1974). (107) Sherman, I. S., Straws, M. G., Nucl. lnstrum. Methods, 177, 285 (1974). (108) Volovik, V. D., Kalinichenko, A. I., LazurikIl'tsufin, V. T., Bull. Acad. Sci. USSR, Phys. Ser. (Engl. Transl.), 38 (5),200 (1974). (109) Kalishi, S.. Latuszek. A,. Siemienczuk, M., Zmija, J., Bull. Acad. Pol. Sci., Ser. Sci. Tech., 22, 65 (1974). (110) Nagle, D. E., Doane, J. W.. Madey, R., Saupe, A,, Mol. Cryst. Liquid Cryst., 26 (1-2), 71 (1974). (111) Kerlman, I. B., Strash, A., Kastner, J., U.S. Patent 3,831,026, 20 Aug. 1974. (112) Burke, H. K., Michon, G. J.. US Patent 3,836,773, 17 Sep. 1974. (113) Grunberg, C., Le Devehat, J., Nucl. lnstrum. Methods, 178 (2), 457 (1974). (114) Arens, J. F., Nucl. Instrum. Methods, 120 (2), 275 (1974). (115) Haffner. J. W., Pearce, L. S., US Patent 3 786 253, 15 Jan. 1974. (116) Swierkowski, S. P., Armantrout, G. A,, Wichner, R., Trans. Nucl. Sci., 21, 302 (1974). (117) Llacer. J.. Wan, M. M. K., Schieber, M., Carlston, R., Schnepple. W., Trans. Nucl. Sci.,
21, 305 (1974). (118) Colmenares, C.. Shapiro, E. G., Barry, P. E., Prevo, C. T., Nucl. Instrum. Methods, 114, 277 (1974). (119) Thiess, P. E., Miley, G. H., Trans. Nucl. Sci., 21, 125 (1974). (120) Nucl. lnstr. Methods, 112 (1-2), (1973). (121) Winder, F. G., Campbell. G. R., Anal. Biochem., 57, 477 (1 974). (122) Wigfieid, D. C., Srinivasan, V., lnt. J. Aool. Radiat. /sot.. 24. 613 (1973). (123) Houtermans,.H., I\iucl. lnstrum. Methods, 112 (I-2), 121 (1973). (124) Reunanen, M. A., U.S. Patent 3 763 371, 2 Oct. 1973. (125) Buchtela, K., Tschurlovits, M., lnt. J. Appl. Radiat. lsot., 24, 531 (1973). (126) Slobodien. M. J., Granlund, R. W.. Health Phys., 27, 128 (1974). (127) Buchteia, K.. Tschurlovits, M., Unfried, E., lnt. J. Appl. Radiat. lsot., 25, (1 1-12), 551 (1974). (128) Spruny, F.. Jad. Energ., 20 (11). 372 (1974). (129) Buchtela, K., Tschurlovits, M., lnt. J. Appl. Radiat. lsot., 24 (9), 531 (1973). (130) Randolph, R. E., lnt. J. Appl. Radiat. lsot., 26 ( I ) , 9 (1975). (131) Elsborg, L.. J. Nucl. Med., 15, 115 (1974).
..
ANALYTICAL CHEMISTRY, VOL. 48, NO. 5, APRIL 1976
(132) Kuznetsov. E. I., Chernov. I. P., Starodub, G. Ya., Yatis. A. A., Sov. At. Energy (Engl. Transl.),35, 1147 (1973). (133) Nelson, J. W., Williams, I., Johansson. T. E., Van Grieken. R. E., Chapman, K. R., Trans. Nucl. Sci., 21, 618 (1974). (134) Pruzinec, J., Tolgyessy, J., Naoum, M. M.. Radiochem. Radioanal. Lett., 20, 73 (1974). (135) Hilaire, M.. Nucl. lnstrum. Methods, 112 (1-2), 383 (1973). (136) Takebayashi, T..Matsuda, H., Umemoto, S., Talanta, 20, 892 (1973). (137) Reimer, G. M., Radiochem. Radioanal. Lett., 21, 339 (1975). (138) Chantret, F., Bull. SOC.Fr. Miner. Crist., 98, 223 (1973). (139) Biernacka, M., Mamont-Ciesla, K., Wasilewski, A., (CLOR-97), (Centralne Lab. Ochrony Radiologicznej, Warsaw (Poland)), NTIS, Springfield, Va., 1973. (140) Paul, D., lsotopenpraxis, 9 (5), 176
(1973). (141) lyer. R. H., Sampathkumar, R., Chaudhuri, N. K.. Nucl. Instrum. Methods, 115, 23 (1974). (142) Wipawin, W. T., Thomas, E. J., Khan, H. A., lnt. J. Radlat. Phys. Chem., 6, 203 (1974). (143) Carpenter, E. S., LaFleur, P. D., Anal. Chem., 46, 11 12 (1974). (144) Garnish, J. D., Proc. SOC.Anal. Chem., 11 (9, 121 (1974). (145) Fisher, D. E., Trans. Am. Nucl. SOC.,18, 84 (1974). (146) Bhatt, R. C., Singh, D., Health Phys., 27, 219 (1974). (147) Varnagy, M. Csikai, J., Szegedi. S., Nucl. lnstrum. Methods, 119, 261 (1974). (148) Varnagy, M., Csikai, J., Szabo, J., Szegedi. S.. Banhalmi, J., Nucl. lnstrum. Methods, 119, 451 (1974). (149) Abdullaev, J., Murtazaev, Kh., Perelygin, V. P., Umarov, G. Ya., Instrum. Exp. Tech. (USSR) (Engl. Transl.), 16, 1662 (1973). (150) Lueck, H. E., Nucl. Instrum. Methods,
116, 613 (1974). (151) Barbier, J., Radioprotection, 6, 51 (1973). (152) Lueck. H. E., Nucl. Instrum. Methods, 114, 139 (1974). (153) Murakami, A., J. Phys. SOC. Jpn., 36, 923 (1974). (154) Khan, H. A,, Nucl. lnstrum. Methods, 114, 61 (1974). (155) Davison, C. C., Nature (London), 247 (5436), 103 (1974). (156) Bonczak, Z.,Natanson, L., Nukleonkla, 18 (12). 577 (1973). (157) Yamakoshi, K., Hashimoto, K., Shimamura, T., Ser. Phys., Astrophys., 34, 133 (1973). (158) Piesch, E., Sayed, A. M., Nucl. lnstrum., Methods, 119, 367 (1974). (159) Nicolae, M., Rev. Roum. Phys.. 18, 1131 (1973). (160) Thackray, M., Roman, D.. Hetherington, E. L. R.. lnt. J. Appl. Radlat. lsot., 25 (2), 49 (1974). (161) Gruhn. T. A., Benton, E. V., Andrus, C. H., Nucl. Instrum. Methods, 119, 131 (1974). (162) Tommasino, L., Armellini. C.. Radlat. Eff., 20, 253 (1973). (163) Abmayr, W. (BMVg-FBWT-72-34), Bundesministerium fuer Verteidigung, Bonn (F. R. Germany), 1972. (164) von Friesen. S. (LUIP-CR-74-2), (Lund University, Sweden), NTIS. Springfield, Va., 1974. (165) Fleischer, R. L., Walker, R. M.. US. Patent 3 770 9 6 2 , 6 Nov. 1973. (166) Durrani, S. A,, Nature (London), 256,
264 (1975). (167) Gentry, R. V.. Cristy, S. S..McLaughiin, J. F.. McHugh, J. A,, Nature (London),244 (5414), 282 (1973). (168) Walder, D. N., Evans, A,, Nature (London), 252 (5485). 696 (1974). (169) Bogdanov, R . V., Kuznetsov, R. A., Sov. Radiochem. (Engl. Transl.), 15, 865 (1973). (170) Merritt. W. F., Nature (London). 250 (5464), 35 1 (1974). (171) Hank, G.. Nucl. News, 18 (14), 1974).
