Raluca Hategan

Bio: Raluca Hategan is an academic researcher from Regional Environmental Protection Agency. The author has contributed to research in topics: Atomic absorption spectroscopy & Inductively coupled plasma. The author has an hindex of 1, co-authored 1 publications receiving 9 citations.

Validation of an analytical method based on the high-resolution continuum source flame atomic absorption spectrometry for the fast-sequential determination of several hazardous/priority hazardous metals in soil

Abstract: The aim of this paper was the validation of a new analytical method based on the high-resolution continuum source flame atomic absorption spectrometry for the fast-sequential determination of several hazardous/priority hazardous metals (Ag, Cd, Co, Cr, Cu, Ni, Pb and Zn) in soil after microwave assisted digestion in aqua regia. Determinations were performed on the ContrAA 300 (Analytik Jena) air-acetylene flame spectrometer equipped with xenon short-arc lamp as a continuum radiation source for all elements, double monochromator consisting of a prism pre-monocromator and an echelle grating monochromator, and charge coupled device as detector. For validation a method-performance study was conducted involving the establishment of the analytical performance of the new method (limits of detection and quantification, precision and accuracy). Moreover, the Bland and Altman statistical method was used in analyzing the agreement between the proposed assay and inductively coupled plasma optical emission spectrometry as standardized method for the multielemental determination in soil. The limits of detection in soil sample (3σ criterion) in the high-resolution continuum source flame atomic absorption spectrometry method were (mg/kg): 0.18 (Ag), 0.14 (Cd), 0.36 (Co), 0.25 (Cr), 0.09 (Cu), 1.0 (Ni), 1.4 (Pb) and 0.18 (Zn), close to those in inductively coupled plasma optical emission spectrometry: 0.12 (Ag), 0.05 (Cd), 0.15 (Co), 1.4 (Cr), 0.15 (Cu), 2.5 (Ni), 2.5 (Pb) and 0.04 (Zn). Accuracy was checked by analyzing 4 certified reference materials and a good agreement for 95% confidence interval was found in both methods, with recoveries in the range of 94–106% in atomic absorption and 97–103% in optical emission. Repeatability found by analyzing real soil samples was in the range 1.6–5.2% in atomic absorption, similar with that of 1.9–6.1% in optical emission spectrometry. The Bland and Altman method showed no statistical significant difference between the two spectrometric methods for 95% confidence interval. High-resolution continuum source flame atomic absorption spectrometry can be successfully used for the rapid, multielemental determination of hazardous/priority hazardous metals in soil with similar analytical performances to those in inductively coupled plasma optical emission spectrometry.

High-Resolution Continuum Source AAS: The Better Way to Do Atomic Absorption Spectrometry By Bernard Welz (Universdade Federal de Santa Caterina, Florianoplis, Brazil), Helmut Becker-Ross, Stefan Florek, and Uwe Heitmann (ISAS, Institute for Analytical Sciences, Berlin). Wiley-VCH Verlag GmbH & Co. KgaA: Weinheim, Germany. 2005. xii + 295 pp. $130.00. ISBN 3-527-30736-2.

Abstract: Description: High–resolution continuum source atomic absorption spectrometry (HR–CS AAS) is the most revolutionary innovation since the introduction of AAS in 1955. Here, the authors provide the first complete and comprehensive discussion of HR–CS AAS and its application to the analysis of a variety of difficult matrices. Published just in time with the first commercial instrument available for this new technique, the book is a must for all those who want to know more about HR–CS AAS, and in particular for all future users. The advantages of the new technique over conventional line–source AAS are clearly demonstrated using practical examples and numerous figures, many in full color. HR–CS AAS is overcoming essentially all the remaining limitations of established AAS, particularly the notorious problem of accurate background measurement and correction. Using a continuum radiation source and a CCD array detector makes the spectral environment visible to several tenths of a nanometer on both sides of the analytical line, tremendously facilitating method development and elimination of interferences. Conceived as a supplement to the standard reference work on AAS by B. Welz and M. Sperling, this book does not repeat such fundamentals as the principles of atomizers or atomization mechanisms. Instead, it is strictly focused on new and additional information required to profit from HR–CS AAS. It presents characteristic concentration for flame atomization and characteristic mass data for electrothermal atomization for all elements, as well as listing numerous secondary lines of lower sensitivity for the determination of higher analyte concentrations. The highly resolved molecular absorption spectra of nitric, sulfuric and phosphoric acids, observed in an air–acetylene flame, which are depicted together with the atomic lines of all elements, make it possible to predict potential spectral interferences.

Removal of Pb and Hg from marine intertidal sediment by using rhamnolipid biosurfactant produced by a Pseudomonas aeruginosa strain

Abstract: The removal of heavy metal contaminants in marine intertidal sediments is an urgent issue. Heavy metal decontamination with rhamnolipid biosurfactant (RB) is a feasible way of solving this problem. In this paper, two heavy metals, lead (Pb) and mercury (Hg), in marine intertidal sediment were removed by prepared RB in laboratory scale. The results showed that Pb and Hg could be efficiently removed from the intertidal sediment in marine environment by using RB produced by a pseudomonas aeruginosa strain. At a critical micelle concentration of 43.73 mg L−1, 62.50% Pb and 50.20% Hg were removed from the marine intertidal sediment sample containing 520.32 mg ⋅ kg −1 of Pb and 13.15 mg ⋅ kg −1 of Hg (dry weight). The pH affected the Pb and Hg removal by RB, and the alkaline eluent medium was favorable for their removal. A major fraction of removed contaminants comprised organic bound to Pb and Hg during RB solution leaching. The content of exchangeable Pb after leaching treatment in the sediment increased followed by the increase of pH of the RB leaching solution. The removal efficiency increased rapidly during the first two days of leaching process. RB performed better than sodium dodecyl sulfate in terms of Pb and Hg removal. Scanning electron microscopy, zeta potential, and surface tension analysis indicated that leaching by RB solution changed the surface characters of sediment grains and led to high Pb and Hg removal efficiencies from the sediment.

Use of High-Resolution Continuum Source Flame Atomic Absorption Spectrometry (HR-CS FAAS) for Sequential Multi-Element Determination of Metals in Seawater and Wastewater Samples

Abstract: The objective of this work is to develop a method for the determination of metals in saline matrices using high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). Module SFS 6 for sample injection was used in the manual mode, and flame operating conditions were selected. The main absorption lines were used for all the elements, and the number of selected analytical pixels were 5 (CP±2) for Cd, Cu, Fe, Ni, Pb and Zn, and 3 pixels for Mn (CP±1). Samples were acidified (0.5% (v/v) nitric acid), and the standard addition method was used for the sequential determination of the analytes in diluted samples (1:2). The method showed good precision (RSD(%) < 4%, except for Pb (6.5%)) and good recoveries. Accuracy was checked after the analysis of an SPS-WW2 wastewater reference material diluted with synthetic seawater (dilution 1:2), showing a good agreement between certified and experimental results.