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Nuclear Science and Technology | Progress Report  165




                                                              using compact XRF spectrometers
               its elemental composition was investigated
               using Neutron Activation Analyses technique    The use of analytical techniques to investi-
               (NAA). The measurements were performed         gate specific ions in body fluids has increase
               in the IEA-R1 nuclear reactor (IPEN/CNEN-SP,   in last year’s presenting significant progress
               Brazil). The elements Cl and Na were identi-   in clinical tests. This motivated us to check
               fied as majorities while the presence of As, Ca,   the performance of two compacts XRF spec-
               Cr, Fe and S were also observed, but in small   trometers, consisting of Ag and Au X-ray mini-
               concentration (μg/L). These data can be used   tubes associated with a Si Drift detector with
               to standardize a specific antilonomic serum    Be window (12.5μm) for this clinical finality.
               for caterpillars (L.  obliqua) coming from dif-  Using the Energy Dispersive X-Ray Fluores-
               ferent regions of Brazil.                      cence technique (EDXRF), specific ions of clin-
                                                              ical relevance, such as, Ca, Cl, Fe and K were
               Characterization of inorganic elements         investigated using standards (certified solu-
               in coxal fluid of Ornithodoros                 tions). The performance of these spectrom-
               brasiliensis (Acari: Arrgasidae)               eters were checked by evaluation of several
                                                              parameter (linearity, reproducibility, accura-
                Ornithodoros brasiliensis tick has distribu-  cy, precision, sensitivity and detection limit)
               tion restricted to the State of Rio Grande do Sul   usually considered for validation procedures
               (São Francisco de Paula). Due to its quick en-  on analytical methods, according to ISO 17025
               gorgement, hydrostatic balance is maintained   and EURACHEM/CITAC norms. The method
               through the secretion of excess body fluids    was proved to give reliable results with lim-
               and ions in the coxal liquid (CL) by coxal gland,   its of detection at levels of 0.23 to 0.58 mgL−1.
               during and after feeding. The biochemical and   Considering that the ranges of the body fluids,
               ionic compositions are unknown; moreover, re-  such as: blood, saliva, serum and urine, are in
               cent investigations suggest that there are some   the order of hundreds of mg L-1, this proce-
               molecules able to help the tick in anti-haemo-  dure is very promising for ions dosage  requir-
               static strategies. The aim of this study was to   ing a small amount of sample (50μL, 10 times
               determine the elemental composition of the     less comparatively to the conventional tests),
               coxal liquid of this tick using NAA. The liquid   simultaneous analysis, short time of analysis
               was collected during and after tick feeding;   (minutes) and simple sample preparation. In
               the ticks feed on rabbits (Oryctolagus cunicu-  addition, this procedure offers a non-destruc-
               lus). The NAA measurements were performed      tive alternative for clinical usage.
               in the IEA-R1 nuclear reactor at IPEN/CNEN-
               SP (3-4.5MW, pool type). These measurements    These compact spectrometers have also po-
               revealed high concentrations of Na, Cl and S   tential use when the biological material is
               suggesting the association with osmotic pres-  scarce, case of the pediatric practice in new-
               sure regulation mechanisms during tick feed-   borns and premature infants (blood collection
               ing and the presence of Br, Mg, K, P and Ca as   is the main cause of transfusions) and in vivo
               trace. The data are crucial for appropriate pu-  tests, in small size animal model (mice and
               rification and characterization of the relevant   rats), in order to evaluate the safety of new
               proteins in this secretion.                    drugs, vaccines and others  medical supplies.


               Quantitative analysis of light elements        Determination of iron supplementation
               (Z<26) in serum and whole blood                in food fortification using X-ray
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