Page 241 - 00. Complete Version - Progress Report IPEN 2014-2016

Environmental Science and Technology | Progress Report 241

Analytical chemistry for tion is required. A Ca / P molar ratio of 1.667 is
environmental diagnosis consistent with the theoretical Ca / P ratio for
calcium hydroxyapatite with a composition-
The Laboratories of Chemistry and Environ- al formula of Ca10(PO4)6(OH)2, whose prop-
mental Diagnosis Center – CQMA have es- erties are well discussed in the literature. The
tablished methodologies for evaluation of aim of this work was implementing and val-
physical-chemical, chemical and toxicolog- idating a methodology for simultaneous de-
ical parameters to support several research termination of major and minor constituents
projects in development for environmental di- in the hydroxyapatite (HA) as well as provid-
agnosis. All methodologies adopted are estab- ing the Ca / P molar ratio. To accomplish these
lished in the standard methods (ASTM, EPA) or achievements, wavelength dispersive x-ray
specified by the clients. The classic methods fluorescence spectroscopy (WDXRF) was ap-
and instrumental techniques analysis such as plied. This is a non-destructive technique that
atomic absorption spectrometry (AAS), induc- requires no chemical treatment, enabling fast
tively coupled plasma emission spectrometry chemical analysis in a wide variety of samples,
(ICP-OES), ion chromatography (IC), gas chro- with no hazardous waste being generated as a
matography (GC), gas chromatography mass result of the process of determination. A stan-
spectrometry (GCMS), high performance liq- dard reference material from NIST (SRM 1400
uid chromatography (HPLC;), X-ray fluores- –Bone Ash) was used to validate the method-
cence (WD-XRFS) have been used. The Center ology for the determination of magnesium,
has been participating in several international phosphorus, potassium, calcium, iron, zinc,
and national interlaboratory programs spon- strontium and the Ca / P ratio in HA samples
sored by: IAEA (International Atomic Energy by WDXRF. The Z-score test was applied as a
Agency), INTI (Instituto Nacional de Tecnologia statistical tool and showed that the calculat-
Industrial, Argentina), SENAC (Brasil), ABACC ed values were of less than 1.8 for all the mea-
(The Brazilian-Argentine Agency for Account- sured analytes.
ing and Control of Nuclear Materials), SABESP.
(Basic Sanitation Company of the State of São X-Ray Fluorescence Techniques
Paulo, Brasil) and Rede Metrológica Rio Grande applied to environmental, geological
do Sul (Brasil). and biological studies Chemical
characterization of nuclear and non-
Determination of a Ca/P Molar nuclear materials R&D activities
Ratio in Hydroxyapatite (HÁ) by
X-Ray Fluorescence Technique The X-Ray Fluorescence Laboratory (LFX) has

worked in environmental, biological and nu-
Hydroxyapatite (HA) is a mineral composed clear areas, establishing new analytical meth-
of calcium phosphate employed for endodon- odologies using the X-ray fluorescence spec-
tics, restorative dentistry and other applica- trometry (WDXRF, EDXRF). Different matrices,
tions in orthopedics and prosthesis. Addition- such as soils, sediments, lubricating oils, treat-
ally, this biomaterial is an inexpensive but ed wood, metal environmental pollution mon-
efficient adsorbent for the removal of heavy itoring trees, organic fluids and nuclear and
metals and other unwanted species of con- non-nuclear materials have been analyzed.
taminated liquid effluents. This is especially The P&D activities have been supported by
interesting when low-cost effective remedia- CNPq, FINEP and IAEA research financial or-