Abstract:A method for total As and Cr determination in seawater sam- ples has been developed. As and Cr were measured using the seaFAST2 automated sample introduction system coupled to an ICP-MS. The sampling system allows on-line sample dilution (10 times) before introduction into the ICP-MS. Calibration was performed using the standard addition method, working in the concen- tration range of 0 to 50 μg L-1 for As and 0 to 25 μg L-1 for Cr. The method shows good sensitivity resulting in LODs and LOQs of 0.3 and 0.9 μg L-1, respectively, for As and of 0.03 and 0.09, respectively, for Cr determina- tion. The method was precise (RSD <2%) and accurate. This method was applied to the determination of As and Cr in different seawater samples from the Galician coast of Spain. The concentrations found ranged from 0.3 to 3.1 μg L-1 for As and from 0.03 to 0.1 μg L-1 for Cr.

Abstract:In this paper, a novel method was developed for the precon- centration, separation, and deter- mination of light (Ce), medium (Eu and Gd), and heavy (Yb) rare earth elements (REEs) by induc- tively coupled plasma mass spec- trometry (ICP-MS), based on the adsorption of Ce3+, Eu3+, Gd3+, and Yb3+ on carbon nanofibers (CNFs) loaded with 1-phenyl-3- methyl-4-benzoyl-5-pyrazone (PMBP). The REEs can be adsorbed quantitatively on CNFs- PMBP in the pH range of 5.0 to 8.0 and then eluted completely with 1.0 mol L-1 HNO3. The experimental parameters for the preconcentration and separation of REEs, such as pH, sample flow rate / volume, eluent concentra- tion / volume, and interfering ions, were examined in detail. Under optimum conditions, the detection limits of this method were found to be 1.5, 0.9, 0.5, and 0.3 pg mL-1 for Ce, Eu, Gd, and Yb, respectively, and their relative standard deviations were less than 5% (c=1.0 ng mL-1, n=9). This method has been applied to the determination of trace REEs in a natural water sample and a certified reference material, GBW 07602 (GSV-1) Combined Sample of Shrub Branch and Leaves, with satisfac- tory results.

Abstract:Some of the species belonging to the genus ferula are known to be used as traditional medicine for treating various diseases in South Asia, the Middle East, and in North Africa. In this study, samples from 20 varieties of plants belonging to 20 species of the genus ferula L. (Apiaceae) were collected from various regions of Turkey. After air dry- ing, the samples were solubilized by using the microwave dissolu- tion technique. The concentra- tion levels of the different elements (Al, B, Ba, Cr, Cu, Fe, Mn, Ni, Pb, Sb, Se, Sr, and Zn) were determined by ICP-OES. The accuracy of the proposed method was verified by analyzing certified reference materials SRM 1573a Tomato and INCT-TL-1 Tea Leaves. The results showed a sig- nificant variation of elemental content, especially for Al, B, Ba, and Fe amongst the fruit- and flower-bearing plants of the dif- ferent plant species of the same genus. This clearly indicates that each plant species has a different absorption and accumulation capacity for different metals. Fur- ther work on the accumulation of these metals in the leaves and shoots of the plants is in progress.

Abstract:A vortex-assisted dispersive liquid-liquid microextraction method for the preconcentration and separation of lead(II) as 2-hydroxypyridine-3-carboxylic acid chelates is presented. CCl4 as the extraction solvent and ethanol as the dispersive solvent were used. The analytical parame- ters optimized included pH, amount of 2-hydroxypyridine-3- carboxylic acid, type and volume of extraction solvent, type and volume of dispersive solvent, sample volume, etc., which affect the extraction efficiency of lead(II). The influence of some matrix ions was also investigated. The detection limit for lead(II) was 8.30 μg L-1 for liquid samples and 0.49 μg g-1 for solid samples. The preconcentration factor of the method was 30. The valida- tion of the method was checked by the analysis of the certified reference materials TMDA-64.2, TMDA 53.3, and SPS-WW2 Waste- water and GBW07425 soil, BCR- 146 R Sewage Sludge, HR-1 Harbour Sediment, and DC73349 Bush Branches and Leaves. The proposed microextraction method was applied to the deter- mination of lead in some natural water, food, soil, and sediment samples.

Abstract:Since fetal exposure to lead begins at the 21st week of preg- nancy, the fetus is at high risk from maternal lead exposure. Although the placenta, an inter- face between the developing fetus and the mother, has mecha- nisms that restrict the entry of toxicants, it cannot protect the fetus from exposure to lead from the mother’s blood. Even low- level lead poisoning causes neuro- developmental toxicity in children including mild mental retardation, low intelligence quo- tients (IQ) and attention span, reading and learning disabilities, hyperactivity and behavioral problems. Also, lead exposure during pregnancy has been shown to increase the risk for abortions, premature births and prenatal deaths. The objective of this study was to detect whether or not maternal blood lead has an effect on newborns. This study involved 95 healthy, non-smoking, non- anemic pregnant women who have lived in Ankara, Turkey, for more than 3 years. Maternal blood samples were obtained from Ankara University, Gynecol- ogy Department of Faculty of Medicine, Dikimevi, Ankara, Turkey. Infant characteristics such as placental weight, birth weight, birth length and head circumference were recorded. Maternal blood lead levels were quantified using Varian AA240Z Graphite Furnace atomic absorp- tion spectrometry (GFAAS), equipped with Zeeman back- ground correction. The method showed linearity in the range of 0–100 μg/L, with a detection and quantification limit equal to 0.34 μg/L and 1.03 μg/L respectively. Maternal blood levels ranged between 12.27 and 433.22 μg/L. The mean maternal blood lead levels were found as 41.80±33.97 ppb. No statistically significant correlation was found between maternal blood lead and birth weight (r=-0.128, p=0.216), birth length (r=-0.081, p=0.434), head circumferences (r=-0.106, p=0.308) and placental weight (r=-0.021, p=0.840).

Abstract:The use of ultrasound radia- tion for the extraction of Cr, K, Na, Pb, and Zn in NPK fertilizer samples was investigated, and their determination by flame atomic absorption (FAAS) and emission spectrometry (FAES). Extraction was performed using 0.05 g of sample, 5.0 mL of HNO3+HCl (50% v/v), and six steps of sonication (20 minutes) in an ultrasound bath, followed by homogenization with a vortex mixer (1 minute). The LOD and LOQ values ranged from 0.6 and 1.8 mg kg-1 and from 3.1 to 6.1 mg kg-1, respectively. The method showed adequate preci- sion (RSD < 5%) and accuracy (recoveries between 90 and 103%). The proposed method requires only small amounts of sample and reagents. All sample pretreatment is carried out in one single flask which avoids sample contamination and ana- lyte loss. The analyte concentra- tions in the samples were found to be below the maximum limits as established by Brazilian legisla- tion.

Abstract:Water pollution because of inorganic contaminants is a seri- ous problem due to the acute toxicities and carcinogenic nature of pollutants. Recently, much attention has been focused on using natural and low-cost adsorbents, especially food residues, for removing toxic metal ions. Batch removal of nickel (Ni(II)), lead (Pb(II)), and cadmium (Cd(II)) from aqueous solution using a natural adsor- bent is described in this study. Effects of various parameters on adsorption capacities such as pH, adsorbent dose, and stirring time were investigated by batch experiments. The maximum adsorption capacities for Ni(II), Pb(II), and Cd(II) ions were 1.6 mg g-1, 125 mg g-1, and 84 mg g-1, respectively. Characterization of the surface modification was per- formed with FTIR measurements. FTIR spectra showed that chemi- sorption takes place at the sur- face of the adsorbent. The Freundlich and Langmuir adsorp- tion isotherms were used to eval- uate the equilibrium data. The characteristic parameters for each isotherm were determined. The Langmuir and Freundlich isotherm provided the best corre- lation for Ni(II), Cd(II), and Pb(II) using banana peel.