EDXRF

The characterization of the pigments and plasters of the wall paints of some Ottoman Mosques have been performed using combined Energy Dispersive X-Ray Fluorescence (EDXRF) and Fourier Transform Infrared (FTIR) spectrometry (both in reflection and transmission modes) techniques. The colored wall paints were obtained from Fatih Mosques of Istanbul-Turkey and Pristina-Kosovo, and Suleymaniye Mosque of Istanbul-Turkey, during the restoration periods of the mosques. The investigations show that the plaster used on the walls has mixed gypsum-lime binders. The pigments identified in wall paints are: cinnabar (HgS), lead red (Pb 3 O 4) and hematite (α-Fe 2 O 3) in red colors, ultramarine blue (Na 8-10 Al 6 Si 6 O 24 S 2-4) as blue and green earth as green colors. The results provide a basis for future restoration of the wall paints.

In this study, the commonly used complementary foods (Unga wa Lishe) for children 0-5 years in Tanzania were analyze for essential and toxic elements in order to assess their nutritional levels. 60 samples were purchased from shops in Dar es Salaam, Moshi and Arusha regions and analyzed using Energy Dispersive X-Ray Fluorescence Spectroscopy (EDXRF). The concentrations of the essential elements were referenced to the Recommended Nutrient Intake (RNI) values for 6-12 months old children while the levels of toxic elements were compared to the Maximum Tolerable Limits (MTL) set by WHO 2004. The nutrient intake for Fe, Zn, Cu and Ca obtained in the complementary foods were less than the RNI values of 11.6 mg/day, 8.3 mg/day, 0.56 mg/day and 500 mg/day respectively set by Joint FAO/WHO and Codex. On the other hand, the concentrations of the toxic elements Ni and As were higher than the MTL (0.2 µg/g and 11 µg/g, respectively) for these elements recommended by EC and WHO 2004, respectively. Further analysis of the complementary foods in Tanzanian is needed to produce more data which will be a guide for the appropriate measures to reduce mineral malnutrition in Tanzania.

The results of the analyses of elemental composition of red and black pigments of Levantine rock art from La Saltadora rock shelters (Valltorta gorge, Castellón, Spain) are presented in this paper. Nondestructive analyses were carried out using a portable energy dispersive X-ray fluorescence (EDXRF) spectrometer developed for in situ analysis. The results revealed the strong presence of calcium in all the analyzed locations due to the contribution of the underlying calcareous bedrock and the overlying crust. Iron is the main element detected in red pigments and manganese in black pigments. Iron and calcium ratios have been found indicative of the degree of preservation of the pictorial layer. Trace elements detected in the pigment composition confirm the use of different raw materials. Therefore, this work illustrates the potential of the portable EDXRF spectrometers for in situ analysis of rock art paintings. Copyright © 2010 John Wiley & Sons, Ltd.

Naiara Viana Campos,a Marcelo Braga Bueno Guerra,*bc Jaime Wilson V. Mello,c Carlos Ernesto G. R. Schaefer,c Francisco José Krug,b Elton E. N. Alvesc and Aristéa A. Azevedo The accumulation and spatial distribution of arsenic and phosphorus in the As-hyperaccumulator fern Pityrogramma calomelanos were investigated by micro-energy dispersive X-ray fluorescence spectrometry (μ-EDXRF). Ferns were grown in half-strength Hoagland nutrient solution without and with 1.0, 10 or 30 × 10−3 mol L−1 As during three weeks. Microchemical As and P maps in different areas of the pinna were obtained by μ-EDXRF, and the same elements were also determined in pelletized powdered samples from the pinna, stipe and root. The reference method for the determination of As and P in the fern samples was a validated method based on microwave-assisted acid digestion followed by ICP OES analysis. Correlations between X-ray characteristic emission intensities and the corresponding As and P mass fractions obtained from the analysis of pelletized test samples exhibited linear correlation coefficients higher than 0.98 (n = 42). Better root mean square errors of prediction (RMSEPs) were obtained when different calibration models were built with pinna, stipe and root test samples separately. Arsenic was accumulated mainly in the pinna midrib, secondary veins, and apical and marginal regions of the pinnule of P. calomelanos, causing alterations in the P distribution. The proposed μ-EDXRF method is an appropriate analytical tool for simultaneously mapping As and P in P. calomelanos. In addition, useful information for either environmental monitoring or phytoremediation studies regarding As contamination is properly obtained.

Naiara Viana Campos,a  Marcelo Braga Bueno Guerra,*bc  Jaime Wilson V. Mello,c  Carlos Ernesto G. R. Schaefer,c  Francisco José Krug,b  Elton E. N. Alvesc and  Aristéa A. Azevedo

The accumulation and spatial distribution of arsenic and phosphorus in the As-hyperaccumulator fern Pityrogramma calomelanos were investigated by micro-energy dispersive X-ray fluorescence spectrometry (μ-EDXRF). Ferns were grown in half-strength Hoagland nutrient solution without and with 1.0, 10 or 30 × 10−3 mol L−1 As during three weeks. Microchemical As and P maps in different areas of the pinna were obtained by μ-EDXRF, and the same elements were also determined in pelletized powdered samples from the pinna, stipe and root. The reference method for the determination of As and P in the fern samples was a validated method based on microwave-assisted acid digestion followed by ICP OES analysis. Correlations between X-ray characteristic emission intensities and the corresponding As and P mass fractions obtained from the analysis of pelletized test samples exhibited linear correlation coefficients higher than 0.98 (n = 42). Better root mean square errors of prediction (RMSEPs) were obtained when different calibration models were built with pinna, stipe and root test samples separately. Arsenic was accumulated mainly in the pinna midrib, secondary veins, and apical and marginal regions of the pinnule of P. calomelanos, causing alterations in the P distribution. The proposed μ-EDXRF method is an appropriate analytical tool for simultaneously mapping As and P in P. calomelanos. In addition, useful information for either environmental monitoring or phytoremediation studies regarding As contamination is properly obtained.