Determination of reference interval values for inorganic elements in whole blood samples of humans and laboratory animals by X-ray fluorescence spectrometry

Abstract

Inorganic elements are responsible for essential bodily functions, such as osmotic regulation, cardiac frequency and contractibility, blood clotting and neuromuscular excitability. The determination of inorganic elements in corporeal fluids such as blood, serum, plasma and urine is used as a monitor for a part or the whole organism; their values, then, are compared with reference interval values. In this study, the energy dispersive X-ray fluorescence spectrometry (EDXRF), applying the Fundamental Parameters method, for the determination of inorganic elements in whole blood samples from humans and laboratory animals, was used. Peripheral blood samples were collected and, before coagulation, 100 μL of sample were deposited onto Whatman No. 41 filter paper and dried, using infrared spotlight. The reference interval values for healthy Brazilian population of Na were found to be 1,788–1,826 μg g−1, of Mg 63–75 μg g−1, of P 602–676 μg g−1, of S 1,519–1,718 μg g−1, of Cl 2,743–2,867 μg g−1, of K 1,508–1,630 μg g−1, of Ca 214–228 μg g−1, of Fe 170–184 μg g−1, of Cu 4–6 μg g−1 and of Zn 1–3 μg g−1. The reference interval values for golden hamster (Mesocricetus auratus) of Na were found to be 1,714–1,819 μg g−1, Mg 51–79 μg g−1, P 970–1,080 μg g−1, S 1,231–1,739 μg g−1, Cl 2,775–2,865 μg g−1, of K 1,968–2,248 μg g−1, of Ca 209–257 μg g−1, of Fe 145–267 μg g−1, of Cu 4–6 μg g−1 and of Zn 3–5 μg g−1. A comparative study between EDXRF and instrumental neutron activation analysis data was carried out and the results for both techniques are statistically equal (α = 0.05). The results contribute for the establishment of reference interval values for Na, Mg, P, S, Cl, K, Ca, Cu and Zn in the healthy Brazilian population and the referred laboratory animal species.