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Despite the globally increasing use of platinum-based cytostatic drugs in the treatment of several types of cancer, only limited attention has been paid to developing a treatment for contaminated liquid samples originating from hospitals, laboratories and manufacturing facilities before and after their administration. In this work, we assess the efficiency of a low-cost adsorbent material, a dithiocarbamate-functionalized silica, in removing cisplatin from a solution containing it in the 0.5–150 mg L−1 concentration range. The advantage of having a surface-functionalized silica is that adsorption can occur by either non-covalent interaction or surface complexation. In the latter case platinum(II) is de-complexed and the original drug is no longer present. Adsorption occurs through a first rapid step, followed by a second slower process. This is likely due to the fact that in our operating conditions (0.9% w/v NaCl), only the original compound is present, for which ligand substitution is known to proceed slowly. The interesting performance, even at low metal concentration, and facile synthesis of the material mean it could be adapted for other applications where the recycling of platinum can be realized.

Drastic reduction in commercialization has favored the interest in lateritic and other minerals as rare earth elements source. In this study, inductively coupled plasma optical emission spectrometr...

The use of Pt (IV) salts in different processes generates, even at low concentrations, toxic residuals that contaminate natural waters. For this reason, the improvement of limit of detection in Pt(...

A multi-energy calibration method was applied for the determination of chromium and nickel in nickeliferous ores by laser-induced breakdown spectroscopy. For the optimization of the laser-induced breakdown spectroscopy parameters, such as laser fluence and delay time, an experimental study was conducted. The best results in terms of trueness were observed using a laser fluence and a delay time of 2500 J/cm2 and 1.1 μs, respectively. A study of sample matrix effects and the determination of emission lines for calibration and normalization of the spectra were undertaken, and appropriate values of those variables were selected for each analyte. The trueness values for chromium and nickel varied from 89 to 114% when certified reference samples (nickeliferous laterite, rock phosphate and contaminated soil) were analyzed.

The dependence of calcium and sodium matrix effects on the total excitation energy of analyte emission signals was used as a tool for the study of excitation mechanisms in radial view mode inductiv...

In the present study, a new method to quantify Al, Cr, Fe, Mg, Mn, and Ni in nickeliferous minerals by laser-induced breakdown spectroscopy (LIBS) is proposed. Thirty-three mineral powder solid samples, previously analyzed by inductively coupled plasma optical emission spectroscopy (ICP OES), and two certified reference materials were used as reference samples for the calibration, and an innovative sample preparation was implemented and described. The use of Bi, Sc and Y as internal standards and the usefulness of other normalization modes were assessed in the normalization of the LIBS emission signals from the analytes. A slurry was made by mixing the solid mineral samples, grinding them into a fine powder, and using water in different proportions. Then, the mixture was homogenized and instantly weighed with a constant mass of a standard liquid solution of Y, which was preliminarily chosen as the internal standard among the three elements assessed, and a 10% (w v−1)-polyvinyl-alcohol solution. After 2 h in an oven at 50 °C, the samples, which were immobilized in the polymer film, were subjected to LIBS analysis. The best sample dilution, emission line and normalization of the emission signal were selected for each analyte. The concentrations of the assessed analytes varied from 0.49 to 26.82% for Al, 0.40 to 2.21% for Cr, 6.8 to 52.93% for Fe, 0.41 to 20.53% for Mg, 0.11 to 1.50% for Mn and 0.23 to 3.02% for Ni. The standard error of validation (SEV) for the newly developed method was 1.34, 0.16, 6.08, 0.88, 0.09, and 0.35% for Al, Cr, Fe, Mg, Mn, and Ni, respectively.

The analytical characteristics of solid-phase extraction method to preconcentrate Cd, Cu and Pb in waters were studied. The 8-hydroxyquinoline immobilized onto TSK Toyopearl vinyl copolymer, 7-(4-ethyl-1-methyloctyl)-hydroxyquinoline adsorbed onto C 18 and C 18 modified with sodium diethyldithiocarbamate chelating were evaluated. The optimized extraction conditions were: pH 7, sample flow rate of 1 mL, elution flow rate of 1 mL min − 1 , sample volume of 50 mL and eluent volume of 5 mL. The three studied materials can be used for the determination of Cd, Pb and Cu in water with repeatability and intermediate precision between 10 and 15%, and recovery between 90 and 111%. However, the 8-hydroxyquinoline immobilized onto TSK Toyopearl vinyl copolymer was the best material because of: a) the best detection limits for Pb, Cd and Cu are achieved, b) only one eluent is needed for the elution of the three metals and c) it showed a higher time durability.

The purpose of the present work was to combine several tools for assessing metal pollution in marine sediments from Cienfuegos Bay. Fourteen surface sediments collected in 2013 were evaluated. Concentrations of As, Cu, Ni, Zn and V decreased respect to those previous reported. The metal contamination was spatially distributed in the north and south parts of the bay. According to the contamination factor (CF) enrichment factor (EF) and index of geoaccumulation (Igeo), Cd and Cu were classified in that order as the most contaminated elements in most sediment. Comparison of the total metal concentrations with the threshold (TELs) and probable (PELs) effect levels in sediment quality guidelines suggested a more worrisome situation for Cu, of which concentrations were occasional associated with adverse biological effects in thirteen sediments, followed by Ni in nine sediments; while adverse effects were rarely associated with Cd. Probably, Cu could be considered as the most dangerous in the whole bay because it was classified in the high contamination levels by all indexes and, simultaneously, associated to occasional adverse effects in most samples. Despite the bioavailability was partially evaluated with the HCl method, the low extraction of Ni (

Laser-induced breakdown spectroscopy (LIBS) is an emerging, multi-elemental and green technique, particularly suitable for the direct analysis of solid samples. In this study, thirty-two superficial sediments collected from Cienfuegos Bay in 2011–2013 were analyzed by LIBS without requiring sample digestion. Al, Ca, Fe, K, Mg, Mn, Na and Ti emission lines were detected in all samples. The full LIBS spectra of the samples were subjected to principal component analysis (PCA) and hierarchical cluster analysis (HCA). Most samples showed a similar emission signal pattern, whereas two samples collected in 2012 and another two in 2013 showed anomalously higher emission signals for Na, Mg and Ca, Mg, respectively. In three of the sediments, the impact of external factors on the ecosystem is the presumable cause of the observed anomalies. The combination of LIBS with multivariate data analysis demonstrated a high capacity for the fast detection of anomalous metal compositions in marine sediments.

In PZT (Lead Zirconate Titanate) ceramics, stoichiometric composition is closely related with physical properties and applications. Laser-induced Breakdown Spectroscopy (LIBS) have shown to be a suitable technique for analyzing many types of solid samples, usually in combination with multivariate techniques. In this study, a method for quick determination of Pb, Zr, Ti and Sr in PZT ceramics using LIBS was proposed. Spectral data is analyzed with PLS (Partial Least Squares), providing results better than Multiple Linear Regression (MLR) and external calibration, when compared with previous determination of the same group of ceramics by PIXE (Particle Induced X-ray Emission). Most of predicted individual concentrations were between 98 and 102% of the reference value for Pb, and between 90 and 110% for the rest of the elements.

This work was aimed at the study of clinoptilolite zeolite as sorbent of Ni(II) from aqueous solutions. Sorption and desorption studies were performed in batch for natural purified, and NH3, NaCl and NaOH treated zeolites at the following optimized conditions: pH 5, sorbent dose of 4 g·L−1, contact time of 30 min and room temperature of 30 ± 2 0C. Sorption capacity increased with the sorbent, as follow: NH3-treated zeolite (9.9 ± 0.6)

In the present paper, a Cuban clinoptilolite-type zeolite was used as lead sorbent. The effect of chemical conditioning with 1 mol L−1 NaCl, NaOH and NH3 solutions at room temperature on the ion exchange capacity for lead uptake by clinoptilolite has been investigated. According to the batch experiments, NH3-treated clinoptilolite exhibited the highest sorption capacity. For this material, the effect that contact time, solid-to-liquid ratio and pH have on the removal of lead from aqueous solutions was comprehensively analyzed, and the most suitable values for these parameters were selected afterward. The pseudo-second-order kinetic model was appropriate for the description of the kinetic performance of the sorption. The Langmuir and Freundlich isotherm models were applied to describe sorption process, and the best fit was reached by using the Freundlich model. The nondestructive techniques, namely particle-induced X-ray emission and X-ray fluorescence, have successfully been evaluated for determining lead concentration in water by its concentration in zeolite. In addition, the more traditional flame atomic absorption spectrometry determination of lead in water was also improved.

The optimization of Citrate Precursor Method to obtain the LiNi0.8Co0.2O2 oxide from the thermal decomposition of the citrate precursor (NH4)3LiNi0.8Co0.2(C6H5O7) is presented. The optimization procedure consists of both the lithium atmosphere and the reaction time control during the decomposition of the citrate precursor. Were obtained and characterized two kind of the (Li1-xNix)(Ni0.8Co0.2)O2 oxides, with and without optimized synthesis conditions, identified as A and B oxides, respectively. The A and B oxides are characterized by compositional, structural and electrochemical studies. The results showed that is possible to reach the ordered oxide phase at smaller reaction time if the lithium atmosphere is controlled. From the combination of the chemical analysis by ICP and the DRX Rietveld structural refinement it is possible to establish the Li, Ni(II), Ni(III) and Co(III) composition with great accuracy. The resulted structural and compositional transformations have a close relation with technological parameters of the rechargeable lithium battery using Li Ni0.8Co0.2O2 oxide as cathode.

Thirteen microelements (Al, As, Cd, Co, Cr, Cu, Fe, Li, Mn, Ni, Ti, V, and Zn) and four macroelements (Ca, K, Mg, and Na) were determined in the edible muscle tissue of fish in Cienfuegos Bay. Eight species, Albula vulpes, Diapterus rhombeus, Gerres cinereus, Haemulon carbonarium, Haemulon sciurus, Micropogonias furnieri, Kyphosus sectatrix, and Lutjanus cyanopterus were studied. The total concentrations and extracted concentrations using HCl were also determined in sediments. The quality of the analysis was guaranteed by validating the used analytical methods with certified reference materials of fish and sediments. The high content of macroelements confirmed the importance of fish as a valuable source of food for the local population. New information is provided on bioaccumulation of toxic elements As, Cd, Cu, Zn, and Cr in fish of the bay, with concentrations that overcame the local or international maximum allowable levels for human consumption in most samples analyzed. A high correlation between the content of toxic elements As, Cd, Zn, and macroelement K in fish and its concentration extracted from sediments using the HCl extraction method was observed.

A simple methodology for the determination of bioavailability of fourteen metals in coastal sediments has been developed by simulating the conditions of digestive process of marine fishes. With this aim, a representative sediment composite sample was treated with hydrochloric acid solutions at different pH values, temperatures and contact times, in the presence and absence of Pepsin and Trypsin. The addition of Pepsin and Trypsin did not affect the extraction of most elements. As a result of the present study, the digestion with a hydrochloric acid solution at pH 1, 40°C and 12h is proposed. Adjustments of the temperature and time reaction could be made according to the specific ecosystem under study. The amount of metal extracted by other methods based on acetic acid was lower than that extracted by HCl treatment proposed.

An Inductively Coupled Plasma Optical Emission Spectrometry method for simultaneous determination of Al, Ca, Cu, Fe, In, Mn, Ni, Si, Sr, Y, Zn, Zr and rare earth elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) in magnesium alloys, including the new rare earth elements-alloyed magnesium, has been developed. Robust conditions have been established as nebulizer argon flow rate of 0.5 mL min and RF incident power of 1500 W, in which matrix effects were significantly reduced around 10%. Three acid digestion procedures were performed at 110 °C in closed PFA vessels heated in an oven, in closed TFM vessels heated in a microwave furnace, and in open polypropylene tubes with reflux caps heated in a graphite block. The three digestion procedures are suitable to put into solution the magnesium alloys samples. From the most sensitive lines, one analytical line with lack or low spectral interferences has been selected for each element. Mg, Rh and Sc have been studied as internal standards. Among them, Rh was selected as the best one by using Rh I 343.488 nm and Rh II 249.078 nm lines as a function of the analytical lines. The trueness and precision have been established by using the Certified Reference Material BCS 316, as well as by means of recovery studies. Quantification limits were between 0.1 and 9 mg kg for Lu and Pr, respectively, in a 2 g L magnesium matrix solution. The method developed has been applied to the commercial alloys AM60, AZ80, ZK30, AJ62, WE54 and AE44., This work was carried out with financial support from the Spanish Ministry of Economy and Competitiveness under Contracts MAT2012-38962 and MAT2015-67586-C3-2-R. Also, part of the present work was supported by the Project “Increase of the reliability in the quantification of metals in environmental samples and advanced materials, from IMRE-UH call 2011–2013. Authors thank Antonio Cantalejo, from COSELA Company, for providing the used DigiPREP Graphite Block Digestion System.

The ratio of the magnesium ion to atom signals with wavelengths of 280.270 and 285.213 nm, respectively, is frequently employed to estimate plasma robustness in inductively coupled plasma optical emission spectrometry. To guarantee a rigorous and accurate calculation of this indicator of the plasma condition, a correction for the difference in the response of the instrument at the two wavelengths of magnesium has been frequently applied. However, the literature reviewed shows inconsistencies in the values of the correction factor used. Also it is notable the lack of information concerning the procedures to calculate such correction factor.In this paper, we propose a simple method for the best estimate of the correction factor from an appropriate measurement of the magnesium atomic and ion background signals, when a blank solution, contaminated by magnesium, is nebulized. We proved that a bad selection of the wavelengths used for background signal estimation can underestimate the correction factor up to a 56%., This work has been performed in the frame of the International Cooperation Program of the Universidad Complutense de Madrid with the Universidad de la Habana; and also as part of the IMRE Project “Improvement of the reliability of the analysis of environmental samples and advanced materials” of 2011 IMRE convocation.

A particle-induced X-ray emission (PIXE) technique has been used in the determination of the principal components Pb, Zr and Ti and the substituting elements Sr, Cr, Nb and La in lead zirconate titanate ceramics. In general, precision of analysis was concentration dependent from each element under study. For Pb, precision varied between 0.13% and 0.16%, at higher concentration of 59.32–64.5%. It was around 6–9% for Sr, Cr and Nb at concentrations of 1% or lower. Particular attention was devoted to the estimation of the analysis trueness. With this purpose, three methods were applied: (1) comparison of PIXE and inductively coupled plasma optical emission spectrometry concentrations, (2) recovery study and (3) comparison with a laboratory standard. Trueness of analysis was around 100 ± 10% for the evaluated elements Pb, Zr, Ti, Sr and Cr. The expected stoichiometry and elemental composition homogeneity of a wide group of produced ceramics were confirmed by the PIXE technique. Copyright © 2012 John Wiley & Sons, Ltd.

Surface sediments of the Bay of Matanzas (Cuba) were studied to assess its environmental quality by using several criteria (metal content index, pollution load index and sediment quality guidelines). Two partial digestion sediment procedures and a modified BCR sequential extraction were used. The concentrations of metals were measured by atomic spectroscopy methods. The founded contents of Cu (2,4-27,9 mg kg-1), Zn (2,5-55,5 mg kg-1) and Ni (8,8-99,2 mg kg-1) were below those reported by other authors. The results obtained suggested that the most polluted sites were 3, 5, and 6. The sequential extraction procedure showed that most of the studied metals were associated to the more stable fractions.

Knowing the metal extraction capacity of a digestion method is crucial for a better environmental interpretation of metal concentrations determined in sediments. One of the main problems at the present is the lack of harmonization of information obtained by two of the most popular sediment partial digestion methods: ISO 11466.3 (aqua regia) and EPA 3050B (HNO3–H2O2–HCl). In the present work, the amount of Cu, Ni and Pb leached by using both methods was compared with the total content of those elements in marine sediments collected, as an example, from the Cienfuegos Bay, Cuba. Similar amounts of Cu were extracted by both methods; while leaching of Ni and Pb were different. Generally, the EPA method extracted more Ni than the ISO method. In contrast, Pb was extracted in a larger amount by the ISO method. Some explanations are given for the observed results. X-ray Diffraction, X-ray Fluorescence, Particle Induced X-ray Emission Spectrometry and Energy Dispersive X-ray coupled to Scanning Electron Microscopy were employed for this purpose. On the other hand, none of the methods studied extracted simultaneously the fraction of all the metals, probably provided by human activity (Theoretical Anthropogenic Fraction) in both sediments studied. The use of ISO 11466.3 or EPA 3050B is recommended since the analytical performance parameters of both, in combination with Flame Atomic Absorption Spectrometry, are adequate. For a better environmental interpretation of the analytical results, information on the extraction efficiency of the selected method for specific elements and sediments under study should also be provided, together with the determined concentrations.

An inductively coupled plasma optical emission spectrometry (ICP OES) method for Pb, Zr, Ti, Sr, Cr, Fe, Cu, Mn, and Al determination in PZT-ceramics is described. Careful analytical work was carried out in order to evaluate precision, accuracy, and matrix interference. Different procedures were investigated for the ceramics decomposition. Axially viewed plasma operating conditions were evaluated for trace elements (Al, Fe, Cu, Mn, and Cr) in presence of sample matrix. The relative standard deviation (RSD) ranged from 0.7 to 3.9%, whereas the analytes recoveries in the spiked samples ranged from 92 to 119%. The detection limits (LODs) of trace elements ranged from 2.4 to 2.6 µg g−1. The developed method is useful for evaluating the PZT-ceramics synthesis.

The inactive biomass of fungus Aspergillus niger O-5 obtained in Cuba was characterized as sorbent of Pb2+ by several structural analysis and others techniques. In addition, the biomass was studied for the separation / preconcentration of Pb2+ from aqueous solution. The maximum biosorption capacity was obtained for the contact time of 30 min and pH 5. The kinetic of sorption process occurred according to the model of Ho. The Freundlich or Langmuir models suitably described the experimental adsorption isotherms. The biomass can be used as sorbent for Pb2+ with a maximum capacity of 4.7 - 6.2 mg g-1. The pretreatment with NaOH solution improved its sorption capacity.

Spatial and temporal variations of sediment quality in Matanzas Bay (Cuba) were studied by determining a total of 12 variables (Zn, Cu, Pb, As, Ni, Co, Al, Fe, Mn, V, CO3 2−, and total hydrocarbons (THC). Surface sediments were collected, annually, at eight stations during 2005–2008. Multivariate statistical techniques, such as principal component (PCA), cluster (CA), and lineal discriminant (LDA) analyses were applied for identification of the most significant variables influencing the environmental quality of sediments. Heavy metals (Zn, Cu, Pb, V, and As) and THC were the most significant species contributing to sediment quality variations during the sampling period. Concentrations of V and As were determined in sediments of this ecosystem for the first time. The variation of sediment environmental quality with the sampling period and the differentiation of samples in three groups along the bay were obtained. The usefulness of the multivariate statistical techniques employed for the environmental interpretation of a limited dataset was confirmed., The authors thank the Iberoamerican University Association of Postgraduate (AUIP) of the Junta de Andalucia, Spain for the financing granted to implement a part of this investigation. The present work was developed as part of the Project ACUMMAMA, 2011–2013 Convocation supported by the Institute of Materials Research and Engineering (IMRE) of the University of Havana and also as part of the 2813, 6009 and 7019 Projects financed by the Oil Research Center of the Ministry of Energy and Mines of Cuba.

An inductively coupled plasma optical emission spectrometry method for the quantitative simultaneous determination of Al, Ca, Co, Cu, Cr, Fe, K, Mg, Mn, Na, Ni, P and Zn in Cuban laterite and serpentine minerals has been developed. Additionally, V and Ti can be quantitatively determined in laterite mineral; Li, Sr, and Zr can be detected in both mineral types and Pb can be detected just in laterite mineral. The microwave-assisted total acid digestion of samples was achieved with HCl+HNO3+HF and HNO3+HClO4+HF acid mixtures for laterite and serpentine samples, respectively. In non-robust plasma operating conditions, the matrix effect characteristics of the laterite sample were dictated by the principal component Fe; while the character of the Mg principal component matrix effect was some how modified by the concomitants Fe and Ni in serpentine sample. The selection of robust conditions decreased the matrix effect. Additionally, the simulation of the matrix samples by introducing the principal component Fe or Mg, correspondingly, in calibration dissolutions was needed to overcome completely the matrix effect over the analysis accuracy. Precision of analysis was very near or lower than 10% for most elements, except Sr (15%) in L-1; and K (15%) and Li (15%) in SNi sample. Accuracy of analysis was around or lowers than 10% for most elements, except K (15%), Na (19%), P (19%) and V (19%) in L-1 sample; and Ca (14%) and P (20%) in SNi sample.

An Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) method for speedy simultaneous determination of 12 elements (Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, P, Sr and Zn) in seaweeds used as human food was optimized and then validated according to Eurachem guidelines. First, instrumental parameters (nebulizer argon flow rate and incident power) were optimized and then analytical lines free from spectral interferences were selected. The method was validated using biological Certified Reference Materials (CRMs). Intra- and inter-assay precision varied from 0.79% to 5.74% and from 2.48% to 8.57%, respectively, depending on the element studied. Within the experimental error, concentrations measured for each element coincided with certified values. Sensitivities, linearity and detection and quantification limits were also determined. Samples of seaweeds (Porphyra and Laminaria) from France, Spain, Korea and Japan were analyzed by using the optimized and validated method. Some considerations on element composition of analyzed samples were made. Seaweeds from the Korean and Japanese coasts tended to display the highest concentrations of P and Al. In contrast, French Porphyra samples showed the lowest levels of Ba, Cu, Fe and Mn. Because great differences in element concentrations were observed due to costal origin and genus, any generalization regarding the algal mineral content may be considered misleading and scientifically inappropriate., The present study was partially supported by the Spanish Ministerio de Investigación y Ciencia project reference AGL2005- 07204-CO2-02 and the Program of Distinguished Visitors and Foreign Researchers of the UCM-Grupo Santander, 2008 Convocation