This study investigated the representativeness of samples for assessing chemical elements in milk bulk tanks. Milk samples
were collected from a closed tank in a dairy plant and from an open top tank in a dairy farm. Samples were analyzed for chemical
elements by instrumental neutron activation analysis (INAA). For both experiments, Br, Ca, Cs, K, Na, Rb and Zn did not present
significant differences between samples thereby indicating the appropriateness of the sampling procedure adopted to evaluate
the analytes of interest.
The degree of homogeneity is normally assessed by the variability of the results of independent analyses of several (e.g.,
15) normal-scale replicates. Large sample instrumental neutron activation analysis (LS-INAA) with a collimated Ge detector
allows inspecting the degree of homogeneity of the initial batch material, using a kilogram-size sample. The test is based
on the spatial distributions of induced radioactivity. Such test was applied to samples of Brazilian whole (green) coffee
beans (Coffea arabica and Coffea canephora) of approximately 1 kg in the frame of development of a coffee reference material. Results indicated that the material do
not contain significant element composition inhomogeneities between batches of approximately 30–50 g, masses typically forming
the starting base of a reference material.
Epiphytic bromeliads have been used as biomonitors of air pollution since they have specialized structures in leaves for absorbing
humidity and nutrients available in the atmosphere. Leaves of five bromeliad species were collected in the conservation unit
Parque Estadual Ilha do Cardoso, São Paulo State, Brazil, and analyzed by INAA. Vriesea carinata was the species showing most accumulation, with the highest mass fractions of K, Na, Rb and Zn. Similar results were previously
found for the same species collected in the dense ombrophilous forest. Chemical composition of bromeliads provided an indication
of the atmosphere status in the conservation unit.
Resuspended soil and other airborne particles adhered to the leaf surface affect the chemical composition of the plant. A
well-defined cleaning procedure is necessary to avoid this problem, providing a correct assessment of the inherent chemical
composition of bromeliads. To evaluate the influence of a washing procedure, INAA was applied for determining chemical elements
in the leaves of bromeliads from Vriesea carinata species, both non-washed and washed with Alconox, EDTA and bi-distilled water. Br, Ce, Hg, La, Sc, Se, Sm and Th showed higher
mass fractions in non-washed leaves. The washing procedure removed the exogenous material without leaching chemical elements
from inside the tissues.
Aiming at the determination of toxic and essential elements in Brazilian commercial bovine milk, 25 ultra high temperature
(UHT) milk samples were acquired in the local market of Piracicaba, SP. The samples were freeze-dried and analyzed by instrumental
neutron activation analysis (INAA) allowing the determination of Br, Ca, Co, Cs, Fe, K, Na, Rb and Zn. When the results were
expressed as concentration (mg·l−1) no significant differences were found. However, considering the dry matter, results showed a clear difference between the
mass fractions (mg·kg−1 d.w.) of skim milk and whole milk for the elements Br, Ca, K, Na, Rb and Zn, indicating that the removal of fat caused a
concentration effect in the dry matter of skim milks. Discrepancies were found between the concentrations of Ca and Na measured
by INAA and the values informed in the labels. Ca showed variations within 30% for most samples, while concentrations of Na
were up to 190% higher than informed values. The sample preparation and the INAA procedure were appropriate for the determination
of Br, Ca, Co, Cs, Fe, K, Na, Rb and Zn in milk samples.
A random sampling was carried out in the coffee beans collected for the preparation of the organic green coffee reference
material in view of assessing the homogeneity and the presence of soil as impurity. Fifteen samples were taken for the between-sample
homogeneity evaluation. One of the samples was selected and 10 test portions withdrawn for the within-sample homogeneity evaluation.
Br, Ca, Co, Cs, Fe, K, Na, Rb, Sc and Zn were determined by instrumental neutron activation analysis (INAA). The F-test demonstrated that the material is homogeneous for Ca, Co, Cs, K and Sc, but not homogeneous for Br, Fe, Na, Rb and Zn.
Results of terrigenous elements suggested negligible soil contamination in the raw material.
Inorganic components were surveyed of some Brazilian cigarette tobacco by INAA. Sixteen different brands were taken from the consumer market and analyzed for As, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, K, La, Na, Rb, Sc, Sm, Sr and Zn elements. Comparisons between the results from this work and those originated from several cigarette tobacco producing countries, indicate significant variation in the levels of some elements.
The tomato culture demands large quantities of mineral nutrients, which are supplied by synthetic fertilizers in the conventional
cultivation system. In the organic cultivation system only alternative fertilizers are allowed by the certifiers and accepted
as safe for humans and environment. The chemical composition of rice bran, oyster flour, cattle manure and ground charcoal,
as well as soils and tomato fruits were evaluated by instrumental neutron activation analysis (INAA). The potential contribution
of organic fertilizers to the enrichment of chemical elements in soil and their transfer to fruits was investigated using
concentration ratios for fertilizer and soil samples, and also for soil and tomato. Results evidenced that these alternative
fertilizers could be taken as important sources of Br, Ca, Ce, K, Na and Zn for the organic tomato culture.
The citrus variegated chlorosis (CVC) disease results in serious economical losses for the Brazilian citriculture. The influence
of CVC disease on the elemental composition of citrus plants was investigated. Leaves of sweet orange varieties Hamlin, Pera
Rio and Valencia were collected from healthy and CVC-affected trees for chemical characterization by instrumental neutron
activation analysis (INAA). Significant differences between healthy and CVC-affected leaves were identified for Ca, Ce, Co,
Eu, Fe, K, La, Na, Nd, Rb, Sc and Sm. Rare earth elements presented consistently higher mass fractions in the healthy leaves.
Tomato is amongst the most consumed vegetables in the world, not only for its culinary versatility but also for its high nutritional
value. In the last years, consumers have shown an increased concern regarding food origin and safety. The organic tomato production
has been a promising alternative for the consumer offering a safer food in relation to environmental, social and nutritional
aspects. This study assessed the chemical composition of tomato seeds produced in both conventional and organic systems by
INAA. The results showed significant differences (p≤0.05) in the mass fractions of Br, Cs, Eu, Fe, K, Mo, Na, Rb and Sm between both systems, indicating influence of the crop
management adopted in the different tomato production systems.