Assessment of teeth elemental content using μ‐EDXRF: effects by in‐office and at‐home bleaching products

The purpose of this in vitro study is to assess whether the elemental content of tooth enamel is altered when bleaching the teeth with bleaching gel. Because of tooth bleaching growing popularity and to match the public demands, manufacturers increased the range of bleaching products available, changing its presentation, techniques and concentration of active principles. This way, two different bleaching products were compared, one for in‐office and another for domestic use. In order to perform this evaluation, sound vestibular surfaces of anterior healthy teeth, extracted for periodontal or orthodontic reasons, were treated with the bleaching products accordingly to manufacturer instructions. Spectra were acquired using the M4 Tornado μ‐XRF setup, and quantitative calculations were performed using fundamental parameter method to determine the elemental composition of the analyzed samples before and after treatment. No significant statistical differences in the mineral content of the analyzed teeth were obtained. Copyright © 2014 John Wiley & Sons, Ltd.     

A background subtraction approach based on complex wavelet transforms in EDXRF

Subtracting the background accurately is one of the most important issues in energy‐dispersive X‐ray fluorescence (EDXRF) spectra processing. This paper presents a novel approach to perform background subtraction based on dual‐tree complex wavelet transform. Compared with real wavelet transform, the proposed method has some attractive properties, including a smooth, nonoscillating, and nearly shift‐invariant magnitude with a simple near‐linear phase encoding of signal shifts. Therefore, it outperforms real wavelet transform to decompose background into low‐frequency components. The effectiveness of the proposed approach is demonstrated via two simulated spectra with different kinds of backgrounds and one measured spectrum from an energy‐dispersive X‐ray spectrometer. Both simulated and experimental results prove that the proposed approach can subtract background in EDXRF spectra effectively. Copyright © 2014 John Wiley & Sons, Ltd.     

能量色散X射线荧光探针用于古陶瓷的工艺与产地研究

利用能量色散X射线荧光(EDXRF)探针技术,研究了旧县坪遗址出土的一件青瓷样品的制造工艺与产地。从青瓷样品的器壁部,用切割法取下一个断面,用探针进行线性扫描分析。结果表明:在胎釉间存在的白色层状物的化学成分介于胎釉之间,断定其应为在烧制过程中经一系列理化反应而形成的反应层。经对该青瓷样品胎釉化学成分的聚类分析,发现其与宋代河南临汝窑青瓷的胎釉化学成分基本一致。并且,该样品与临汝窑青瓷在釉色和装饰风格上都相近。因此,旧县坪遗址的这件青瓷样品应为临汝窑制品。     

Epsilon5高能偏振能量色散X-射线荧光光谱仪测定垃圾焚烧灰渣中有害元素

使用粉末样品压片制样,用Epsilon5高能偏振能量色散X射线荧光(EDXRF)光谱仪测定垃圾焚烧灰渣中S、Cl、Ba、Cr、Cu、Na、Mn、Pb、Zn、Cd、As、Mo等多种有害元素,采用土壤、水系沉积物、海底沉积物、矿物等国家标准物质和人工合成标样作为校准。     

The amounts Fe, Ba, Sr, K, Ca and Ti in some lichens growing in Erzurum province (Turkey)

The amounts of Fe, Ba, Sr, K, Ca and Ti were determined qualitatively and quantitatively by using energy-dispersive X-ray fluorescence in eight lichen species, Pinus sylvestris, rock and soil in district of Erzurum province (Turkey). Lichen species were Cetraria pinastri (Scop.) Gray, Dermatocarpon miniatum (L.) W. Mann, Lecanora muralis (Schreb.) Rabenh., Pseudevernia furfuracea (L.) Zopf., Ramalina capitata (Ach.) Nyl., Rhizoplaca chrysoleuca (sm.) Zopf., Rhizoplaca melanophthalma (DC.) Leuckert & Poelt, and Xanthoparmelia somloensis (Gyeln.) Hale. The standard addition method was used for the determination of the concentration of Fe, Ba, Sr, K, Ca and Ti. The experimental setup consists of a Si(Li) detector with a resolution of at and annular ⁵⁵Fe and ²⁴¹Am radioactive sources. By the use of intersite, interelement and interspecies comparisons, it is concluded that some metals within the thalli of lichens in Erzurum province may reach high levels even when these plants are growing in rural and isolated sites.     

Multielemental evaluation of garbage bags by EDXRF

Garbage bags have been broadly used for collecting household waste in Brazil and worldwide. Many of these bags are made from recycled polymers, and the presence of harmful elements is a matter of concern. In this study, an energy dispersive X-ray fluorescence (EDXRF) approach for direct analysis of garbage bags is proposed. The concentrations of K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr and Pb were determined in 14 garbage bags of different brands purchased from local markets in Piracicaba, São Paulo State, Brazil. The EDXRF technique proved to be an effective technique for multielemental, environmentally friendly and direct garbage bag monitoring. For most samples, Ca and Ti presented at minor concentration ranges and K, Cr, Mn, Fe, Ni, Cu, Zn and Pb at minor and trace levels. The EDXRF limits of quantification were K: 220; Ca: 112; Ti: 42; Cr: 19; Mn: 13; Fe: 9.2; Ni: 5.7; Cu: 5.3; Zn: 5.2; Br: 12; Rb: 20; Sr: 28 and Pb:17 μg g^–1. The samples had variable thicknesses, with a superficial density variation of 1.5 to 23% among the triplicates. The trueness of the method was checked by analysing the National Institute of Standards and Technology standard reference material SRM2783.     

Study on the chemical composition features of Longquan celadon excavated from the Chuzhou site of Huai'an City in Jiangsu Province by EDXRF

A mass of Longquan celadon shards were excavated from the Chuzhou site of Huai'an City in Jiangsu Province, China. These celadon shards were fired during the period of the Late Yuan Dynasty to the Tianshun era of the Ming Dynasty, as identified by archaeologists at Nanjing Museum. In order to research the chemical composition features of this ancient celadon porcelain, energy dispersive X-ray fluorescence (EDXRF) for non-destructive analysis was used to determine the chemical composition of the porcelain body and glaze in these shards. The results indicate that Ti and Fe in the body of Longquan celadon are characteristic elements which can distinguish porcelain produced during the Late Yuan Dynasty from those produced in the Ming Dynasties. The results of the principal component analysis (PCA) show that different body and glaze raw materials were used for the production of porcelain in different periods and the raw materials of the body and glaze are also different for various vessel shapes. The chemical compositions in the porcelain body of civilian ware are slightly different. The imperial and civilian Longquan celadon porcelains produced during the Hongwu era to the Tianshun era of the Ming Dynasty are distinguishable by the MnO, Fe₂O₃, Rb₂O and SrO content in their porcelain glaze.     

Elemental concentration analysis in some plant samples by EDXRF at Trabzon

The elemental analysis of some plant samples have been carried out in Trabzon region (Turkey) using energy-dispersive X-ray fluorescence (EDXRF) spectrometry. We have analyzed plant samples for nine stations using 1.85 GBq ⁵⁵Fe radioactive sources. We have found that potassium and calcium within 0.3-1.4% and 0.3-2.8% were present in concentration in plants for every station, respectively. The concentration of Cl and Ti generally changed according to the plant species and the sampling station.     

Determination of copper,iron, nickel and zinc in ethanol fuel by energy dispersive X-ray fluorescence after pre-concentration on chromatography paper

This paper presents an alternative analytical method employing energy dispersive X-ray fluorescence (EDXRF) to determine copper, iron, nickel and zinc ions in ethanol fuel samples after a pre-concentration procedure. Our pre-concentration strategy utilizes analyte retention on cation exchange chromatography paper, a convenient substrate for direct EDXRF measurements. The repeatability, expressed in terms of RSD of standard solutions containing 0.25 μg mL⁻¹ of Cu, Fe, Ni and Zn, and calculated from fifteen consecutive measurements, was 2.5, 2.8, 3.0, and 2.7%, respectively. The limits of detection (LOD), defined as the analyte concentration that gives a response equivalent to three times the standard deviation of the blank (n = 10), were found to be 13, 15, 15 and 12 μg L⁻¹ for Cu, Fe, Ni and Zn, respectively. The proposed method was applied to Cu, Fe, Ni and Zn determination in hydrated ethanol fuel samples collected from different gas stations.