**2. Neutron activation analysis in Brazil in the new millennium**

Brazil has developed technology based on nuclear research reactors, two (IPEN and CDTN) work on neutron activation analysis. At IPEN, São Paulo, there is one research reactor (a 5 MW pool type) and a cyclotron both involved with radioisotopes production. At the CDTN, Belo Horizonte, there is a very active Triga research (IPR-R1) reactor [5]. Two unique duties in both of these institutes are promoting of basic nuclear teaching for students and workers in nuclear industry and embracing the applied research in many fields like: medicine, nutrition, animal sciences, geology, environmental sciences among others [5].

There is an interesting study of lunch meals served at the Cafeteria of the School of Public Health used by students and workers in the University of Sao Paulo (USP). That study could be considered an turning-point in Nuclear Analytical Applications in Brazil, giving pace for a new generation of studies in Life Sciences. The aim of that study from 2000 was to assessing the nutritional adequacy of diets served to University students related to essential elements and also monitoring for some toxic elements [6].

in many and varied areas of Sciences, including: material engineering, chemistry, agronomy, animal sciences and nutrition. Later, the Hevesy and Levi's technique were identified as

180 Imaging and Radioanalytical Techniques in Interdisciplinary Research - Fundamentals and Cutting Edge Applications

The Instrumental Neutron Activation Analysis (NAA) has a great advantage to other (humid) techniques due to the absence of effects of chemical binding to the trueness of results since the NAA is the only technique for quantitative element determination based on phenomena occurring in the atomic nucleus. The total dissolution may not be guaranteed for the entire

Other outstanding characteristics include: element specificity, multi-element determination

Potential interferences, sources of error and contributions to uncertainty of measurement are

Some authors define NAA as "Mature, completed in development'', a stage in which the initial problems have been overcome. However, there are various analytical challenges in the many applications for which INAA may be the preferred technique to obtain information on

Oppositely, applying others analytical techniques to study solid samples by flame atomic absorption spectroscopy, graphite furnace absorption spectroscopy, inductively coupled plasma spectroscopy, or inductively coupled plasma mass spectrometry, the sample must first be digested to get the analyte metals in solution. Digestion dissolves only those fractions of metals that can be put into solution under relatively extreme conditions and therefore enables measurement of available metals. Sample digestion by humid procedures generally uses highly corrosive reagents that are strong acids and strong oxidants and demand expert personnel using the proper equipment, including fume hoods and adequate personnel protection. It is expected new developments of high-powered microwave digestions systems

Neutron Activation Analysis [2].

sample in humid techniques [3].

capacity, and sensitivity [2,3].

well known and quantifiable [3].

elements and their concentrations [3].

coupled to these "open-sample dependent" techniques [4].

sciences, geology, environmental sciences among others [5].

**2. Neutron activation analysis in Brazil in the new millennium**

Brazil has developed technology based on nuclear research reactors, two (IPEN and CDTN) work on neutron activation analysis. At IPEN, São Paulo, there is one research reactor (a 5 MW pool type) and a cyclotron both involved with radioisotopes production. At the CDTN, Belo Horizonte, there is a very active Triga research (IPR-R1) reactor [5]. Two unique duties in both of these institutes are promoting of basic nuclear teaching for students and workers in nuclear industry and embracing the applied research in many fields like: medicine, nutrition, animal

There is an interesting study of lunch meals served at the Cafeteria of the School of Public Health used by students and workers in the University of Sao Paulo (USP). That study could be considered an turning-point in Nuclear Analytical Applications in Brazil, giving pace for a Since 2000, our research group has been dedicated to apply Neutron Activation Analysis in Animal Sciences. Starting from acquiring data for minerals in bovine tissues of the Brazilian cattle; at that point we could not find any study involving such tissues in Brazil in the nutrition field [7].

In that first study [7], our objective was focused to assess the elemental composition of animal tissues to support health and nutritional studies. Since cattle were and still are the most prevalent source of protein among Brazilian families, including meat, milk and dairy products. Determining the elemental concentration in cattle tissues is especially important because these materials are used for multipurpose objectives such as the assessment of animal health, the quality of human foods consumed, and as a potential environmental biomonitor. Chromium, copper, sodium, potassium, iron, and zinc levels were determined in bovine tissues—kidney, liver and muscle—from cattle bred and raised in a potentially metal contaminated region because of mineral activities.

We verified the essential element concentration and possible contamination by toxic elements in cattle tissues that can affect human nutrition. There was a good agreement the between values reported international organizations such USDA and FAO and the Brazilian analytical results obtained; the required data quality was also achieved. The higher iron, chromium, and copper concentrations could reflect the influence of the fate of environmen‐ tal contaminants depositing in the animal tissues by biochemical processes. The pollu‐ tants in the environment reaching the livestock through water and forage may have caused it. In this first study it is not possible to affirm that the higher iron, chromium, and copper concentrations mean that these elements are playing the role of toxic elements because it was a preliminary sampling. However, the presence of such elements that is not report‐ ed elsewhere should be verified in detail during other studies. It is important to analyze animal tissues since this matrix can be used an efficient biomonitor to assess the ani‐ mal's health, and the quality of human foods as well. The application of k0-instrumental neutron activation analysis was considered an effective multi-elemental method used to determine mineral concentration of biological material.

It is well established that (tropical) Brazilian soils are phosphorus deficient or/and have low phosphorus bioavailability as long most of the phosphate molecules are biding in insoluble composts [8]. This phosphorus deficiency affects both crops and livestock produced in Brazil. To avoid it, it has been applied phosphorus sources in soil, plant and animal nutrition. The most popular sources of phosphorus are rock phosphates, dicalcic phosphate, and in some cases, bone meal.

Rock phosphates are a source of many elements considered as contaminants in animal nutrition and to the environment as well. These product are plenty used in Animal Nutrition.
