An investigation of computer coupled automatic activation analysis and remote lunar analysis Quarterly progress report, 1 Nov. 1962 - 1 Feb. 1963

Mark II automatic activation analysis system, influence of radiation on silver ion migration in mice, selenium determination in submicrogram quantities, and remote lunar analysi

Trace Element Studies Using Activation Analysis

This thesis describes the estimation of elements at trace levels in biological samples, mainly human, by the technique of thermal neutron activation analysis. The work falls into three main parts. In the first part the history, background, principles and details of the activation analysis technique are described; in the second part details of the methods used and their modification or development are described; and in the third part the applications made to trace element studies are described. In neutron activation analysis the induced radioactivity of an element enables its concentration in a sample to be assessed. The advantages of this technique made it a suitable choice for the determination of the low levels of trace elements in biological tissue. A search of the literature for neutron activation analysis techniques reveals that analysis methods for many of the elements have been described already. Methods found suitable for copper, mercury and cadmium analyses are used as described. Methods described for arsenic, gold, manganese and zinc analyses are modified to improve them and make them more suitable. For selenium and barium analyses it is necessary to develop new methods. The development of these methods is described and discussed. All methods are then applied to the trace element analyses described in the following section. The trace element studies carried out fall into three fields of research: (1) A study of the role in tissue of some trace elements, (2) A study into environmental uptake by man, and clinical application of the analysis technique, (3) A study of specimens of historical interest. (1) The question of whether an element is essential or nonessential to a tissue may be indicated by distribution studies. Using this as a basic criterion, manganese, cadmium and selenium are investigated in the major tissues of the human body. Manganese is also investigated in Rhesus monkey tissue and levels of human and monkey tissue compared. Manganese and selenium are established as essential and cadmium is found to be nonessential. The role of barium in the human lung is investigated and it is shown to be nonessential and to accumulate in the broncopulmonary lymph nodes. The variation with time of copper levels in the nail and skin of an individual is investigated and shown to be held within a narrower range than that found in the whole population. (2) A study is made of the occupational uptake of mercury in dental groups. Workers who were industrially exposed to mercury, arsenic and copper are also examined. A high uptake is found in all these groups. A feature, that is found common to all groups, is that a surprisingly high amount of absorption could be tolerated in many cases, without the associated occurrence of poisoning symptoms. Thus, the value of the analysis as a means of detecting a potential health hazard is demonstrated. Arsenic analysis of hair, nail and urine is shown to be of use in monitoring a case of known arsenic poisoning. Head hair analysis enables, very elegantly, a record of previous uptake to be found. Analysis for arsenic and mercury is able to be extended into further clinical application and is proved to be useful. Zinc levels in salivary glands are investigated to see what part zinc played in their function. Lower zinc levels than in other soft tissue are found, indicating that here fewer zinc associated metabolic processes are involved. A possible association between zinc in saliva and the labial gland is found. (3) The value of the activation technique for the examination of small historical specimens is demonstrated by the analysis undertaken of mercury in head hair from Robert Burns and of arsenic in head hair from Napoleon Bonaparte. It is thus shown that Burns may well have been suffering from mercury poisoning, but the evidence is not conclusive. It is found that there is much evidence to suggest that Napoleon was suffering from consistent arsenic poisoning during 1816. In conclusion, the technique of neutron activation analysis is developed and applied to biological materials. It allows simple, but precise, investigation to be made into trace element levels in both living subjects and in other tissues where only small samples are available

The Determination of Trace Elements in Biological Systems by Activation Analysis

An introductory section defines the scope of the study, in terms of the elements to be determined, and a review of the techniques availability especially thermal neutron activation analysis. A discussion of the activation analysis technique is presented, including not only the relationship of this technique to the more usual analytical techniques, but also a synopsis of its application by previous workers in several fields

The determination of the Uranium and Thorium content of certain Saudi Arabian ores by Neutron Activation Analysis

http://www.worldcat.org/oclc/1162867

A Neutron Activation Analysis Technique for Determination of the Precious Metals and its Application to a Study of their Geochemistry

A neutron activation analysis procedure for the simultaneous determination of Ru, Pd, Os, Ir, Pt and Au has been developed. It consists principally of distillation, anion exchange, solvent extraction and precipitation steps and was used to determine all of these metals in meteorites as well as Pd, Ir and Au in sulphide minerals from the Sudbury Nickel Irruptive. The accuracy of the method was checked against G-1 and W-1 and a sulphide standard. A literature survey of the geology of the Sudbury Nickel Irruptive and a description of the geology of the Strathcona mine are presented. A detailed description of the inorganic chemistr! and its bearing on the geochemistry of the precious metals, with special reference to basic rocks is given. Analytical results for Pd, Ir and Au in a large number of pyrrhotite and chalcopyrite samples and a smaller number of sulphide and oxide minerals and an ultramafic xenolith are presented. Arsenic was determined in 15 of the sulphide samples and found to be highly correlated with Pd. The genesis of the Strathcona ores is discussed and the differential behaviour of the precious metals during fractionation or a sulphide-rich basic magma is described. Seven carbonaceous and two enstatite chondrites were analysed and the data evaluated with respect to estimation of the cosmic abundances of these metals. ThesisDoctor of Philosophy (PhD