Publicaciones 2011-2020

@article{marcaida2017optimization,
title = {Optimization of Sample Treatment for the Identification of Anthraquinone Dyes by Surface-Enhanced Raman Spectroscopy},
author = { I. Marcaida and M. Maguregui and H. Morillas and C. Garcia-Florentino and V. Pintus and T. Aguayo and M. Campos-Vallette and J. Madariaga},
url = {/brokenurl#<Go to ISI>://WOS:000395057500024},
doi = {10.1007/s00216-016-0169-6},
issn = {1618-2642},
year = {2017},
date = {2017-01-01},
journal = {Analytical and Bioanalytical Chemistry},
volume = {409},
number = {8},
pages = {2221-2228},
abstract = {The study and characterization of old artifacts such as pigments requires the use of techniques that need a small amount of sample to perform the analysis because of the high value of these samples. In recent years, organic molecules such as anthraquinone dyes have been identified by surface-enhanced Raman spectroscopy (SERS). However, different sample treatments must be applied to isolate the organic dye from the mordant, which produces great fluorescence in the Raman measurements. In this work, optimization of sample treatment for the SERS analysis of anthraquinone dyes was performed. Sample mass, the organic solvent, and its volume were optimized and different slide materials and excitation lasers were compared to choose the best conditions for the identification of the dyes. The optimization of sample treatment resulted in 5 mg of sample as the optimum amount. Further, two consecutive extractions with 0.5 mL of ethyl acetate was the best option for the extraction of the dye. A quartz slide was used instead of a glass slide to reduce background signal, and an excitation laser of 532 nm offers better results than one of 785 nm. The optimized method was applied to the characterization of the dyes used in Pompeian pink and purple lake pigments. Alizarin and purpurin anthraquinone dyes, obtained from madder lake, were identified as the organic colorants. The SERS results were confirmed by those obtained by means of UV-visible spectroscopy.},
keywords = {anthraquinone, dyestuffs, extraction, lake lake, liquid-liquid madder nanoparticles, pigment, pigments, purple, raman scattering, sers, silver, spectroscopy, surface-enhanced},
pubstate = {published},
tppubtype = {article}
}

@article{RN277,
title = {Adsorption of as (V) by Poly (N-Octyl-4-Vinylpyridinium) Bromide: Determination of as (V) by Direct Measurement of Fluorescence on the Solid Phase},
author = { J. Gonz\'{a}lez-Navarrete and M.I. Toral and A. Leiva and M. Yazdani-Pedram and H. Rios and X. Briones and M. Urz\'{u}a},
url = {/brokenurl#<Go to ISI>://WOS:000390510200015},
doi = {10.1016/j.reactfunctpolym.2016.10.011},
issn = {1381-5148},
year = {2016},
date = {2016-01-01},
journal = {Reactive & Functional Polymers},
volume = {109},
pages = {112-119},
publisher = {2016 Elsevier B.V.},
abstract = {Adsorption of As (V) by poly (N-octyl-4-vinylpyridinium) bromide (P4VPyC8), used as solid phase, was studied. Determination of As (V) was carried out by direct measurement of the fluorescence intensity on the solid phase. Adsorption variables were optimized for obtaining optimum values of pH and agitation time, where pH 9.0 and 60 min were established as optimum values. The adsorption of arsenic (V) was characterized by infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. It was found that the fluorescence of the solid phase increases as the concentration of arsenic increases. Linearity was observed in the concentration range 6.80 to 90.0 mu g L-1. The detection limit for determination of As (V) by this method was 2.24 mu g L-1 and the relative standard deviation (RSD) was 1.72%. The amount of retained As (V) was 0.154 mg/g of solid phase. The determination of As (V) in a sample of tap water by this method was well compared with the value reported by an external certified laboratory. Therefore, the method of analysis proposed here could be used as a screening methodology for monitoring the fulfillment of the norm for arsenic concentration in tap water.},
keywords = {adsorption, arsenate, arsenic arsenic, atomic-absorption-spectrometry, carbon drinking-water, extraction, fluorescence, heavy-metal ions, nanotubes, performance phase, preconcentration, removal, samples, solid toxic water},
pubstate = {published},
tppubtype = {article}
}

@article{RN205,
title = {Synthesis and Magnetic Properties of Chromium-Based Cu(Cr2-Xtix)S-4 Thiospinels and Their Deficient Structures Cu1-Y Rectangle Ycr2-Xtixs4 Obtained by Copper Extraction},
author = { P. Barahona and A. Gald\'{a}mez and F. Lopez-Vergara and V. Manriquez and O. Pena},
url = {/brokenurl#<Go to ISI>://WOS:000342613000010},
doi = {10.4067/S0717-97072014000100011},
issn = {0717-9707},
year = {2014},
date = {2014-01-01},
journal = {Journal of the Chilean Chemical Society},
volume = {59},
number = {1},
pages = {2294-2298},
abstract = {The crystalline structure of spinels is extremely flexible due to the presence of several sublattices in which the cations can be distributed and localized in different crystallographic sites depending on their sizes, oxidation states or coordination numbers. Cationic substitution and ions- extraction are appropriate tools to change the oxidation state inside the spinel structure, thus substantially modifying the magnetic properties. The spinel sulfide CuCr2S4 is a metallic ferromagnet with T-C=377 K, where Cr is mixed- valence Cr3+/Cr4+, while CuTi2S4 is a Pauli paramagnet, with Ti in a mixed- valence state (singlet ground state for Ti3+; nonmagnetic},
keywords = {copper cr, cuti2s4, cuzr2s4 electrical-properties, extraction, ferrimagnetic intercalation, lithium magnetoresistance, mixed perovskites, spin-glass, thiospinel, valence},
pubstate = {published},
tppubtype = {article}
}

@article{RN16,
title = {Determination of Cobalt in Water Samples by Photoacoustic Spectroscopy with a Solid-Phase Spectrophotometry Approach Using 3-(2-Pyridyl)-5,6-Bis (4-Sulfophenyl)-1,2,4-Triazine},
author = { R. Saavedra and C. Soto and J. Yanez and M.I. Toral},
url = {/brokenurl#<Go to ISI>://WOS:000290749600008},
doi = {10.1016/j.microc.2011.02.003},
issn = {0026-265x},
year = {2011},
date = {2011-01-01},
journal = {Microchemical Journal},
volume = {98},
number = {2},
pages = {220-224},
publisher = {2011 Elsevier B.V.},
abstract = {This work forms part of an investigation which seeks to determine metal complexes in a solid phase by photoacoustic spectrometry (PAS). Results of spectral determination of Co(II) complexes are introduced. The method is based on Co(II) calorimetric reaction with 3-(2-pyridyl)-5,6-bis(4-sulfophenyl)-1,2,4-triazine (FST, ferrozine) retained on an anion-exchange resin, DEAE Sephadex A-25. The immobilization of Co(II) on the solid phase is combined with PAS measurement. A numerical approach is applied to reduce noise in the spectral data. At lambda = 477 nm, the calibration for Co(II) is linear over the range 14-300 mu gL(-1). The Co(II) concentration in water samples was determined by conventional photoacoustic measurement. The relative standard deviation (R.S.D.) of the method for the calibration is <5%. Under optimized conditions, the obtained analytical features were LOD 14 mu gL(-1) and LOQ 45 mu gL(-1).},
keywords = {atomic-absorption-spectrometry, chelating cobalt, emission-spectrometry, extraction, ferrozine ferrozine, icp-ms, nickel, online optothermal phase photoacoustic preconcentration, resin, solid spectroscopy, trace-metals, window},
pubstate = {published},
tppubtype = {article}
}