Development of an ionic liquid-based dispersive liquid–liquid microextraction method for the determination of nifurtimox and benznidazole in human plasma

Dispersive ionic liquid–liquid microextraction combined with liquid chromatography and UV detection was used for the determination of two antichagasic drugs in human plasma: nifurtimox and benznidazole. The effects of experimental parameters on extraction efficiency—the type and volume of ionic liquid and disperser solvent, pH, nature and concentration of salt, and the time for centrifugation and extraction—were investigated and optimized. Matrix effects were detected and thus the standard addition method was used for quantification. This microextraction procedure yielded significant improvements over those previously reported in the literature and has several advantages, including high inter-day reproducibility (relative standard deviation¼1.02% and 3.66% for nifurtimox and benznidazole, respectively), extremely low detection limits (15.7 ng mL1 and 26.5 ng mL1 for nifurtimox and benznidazole, respectively), and minimal amounts of sample and extraction solvent required. Recoveries were high (98.0% and 79.8% for nifurtimox and benznidazole, respectively). The proposed methodology offers the advantage of highly satisfactory performance in addition to being inexpensive, simple, and fast in the extraction and preconcentration of these antichagasic drugs from human-plasma samples, with these characteristics being consistent with the practicability requirements in current clinical research or within the context of therapeutic monitoring.Fil: Padró, Juan Manuel. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química. Grupo Cromatografía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marsón, María Elena. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas. Área de Toxicología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mastrantonio Garrido, Guido Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas. Área de Toxicología; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química. Laboratorio de Servicios a la Industria y al Sistema Científico; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Altcheh, Jaime Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez". Servicio de Parasitología y Chagas; ArgentinaFil: García Bournissen, Facundo. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez". Servicio de Parasitología y Chagas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Reta, Mario Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química. Grupo Cromatografía; Argentin

Predicting the partitioning of biological compounds between room-temperature ionic liquids and water by means of the solvation-parameter model

The partition coefficients, PIL/w, for different probe molecules as well as for compounds of biological interest between the room-temperature ionic liquids (RTILs) 1-butyl-3-methylimidazolium hexafluorophosphate, [BMIM][PF6], 1-hexyl-3-methylimidazolium hexafluorophosphate, [HMIM][PF6], 1-octyl-3-methylimidazolium tetrafluoroborate, [OMIM][BF4] and water were accurately measured. [BMIM][PF 6] and [OMIM][BF4] were synthesized by adapting a procedure from the literature to a simpler, single-vessel and faster methodology, with a much lesser consumption of organic solvent. We employed the solvation-parameter model to elucidate the general chemical interactions involved in RTIL/water partitioning. With this purpose, we have selected different solute descriptor parameters that measure polarity, polarizability, hydrogen-bond-donor and hydrogen-bond-acceptor interactions, and cavity formation for a set of specifically selected probe molecules (the training set). The obtained multiparametric equations were used to predict the partition coefficients for compounds not present in the training set (the test set), most being of biological interest. Partial solubility of the ionic liquid in water (and water into the ionic liquid) was taken into account to explain the obtained results. This fact has not been deeply considered up to date. Solute descriptors were obtained from the literature, when available, or else calculated through commercial software. An excellent agreement between calculated and experimental log PIL/w values was obtained, which demonstrated that the resulting multiparametric equations are robust and allow predicting partitioning for any organic molecule in the biphasic systems studied.Fil: Padró, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; ArgentinaFil: Ponzinibbio, Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química. Laboratorio de Estudio de Compuestos Orgánicos; ArgentinaFil: Agudelo Mesa, Leidy Bibiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; ArgentinaFil: Reta, Mario Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentin

Development of an ionic-liquid-based dispersive liquid–liquid microextraction method for the determination of antichagasic drugs in human breast milk. Optimization by central composite design

Chagas disease constitutes a major public health problem in Latin America. Human breast milk is a biological sample of great importance for the analysis of therapeutic drugs, as unwanted exposure through breast milk could result in pharmacological effects in the nursing infant. Thus, the goal of breast milk drug analysis is to inquire to which extent a neonate may be exposed to a drug during lactation. In this work, we developed an analytical technique to quantify benznidazole and nifurtimox (the two antichagasic drugs currently available for the medical treatment) in human breast milk, with a simple sample pre-treatment followed by an ionic-liquid-based dispersive liquid–liquid microextraction combined with high-performance liquid chromatography and UV detection. For this technique, the ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate has been used as the “extraction solvent”. A central composite design was used to find the optimum values for the significant variables affecting the extraction process: volume of ionic liquid, volume of dispersant solvent, ionic strength, and pH. At the optimum working conditions, the average recoveries were 77.5 and 89.7%, the limits of detection were 0.06 and 0.09 μg mL-1 and the inter-day reproducibilities were 6.25 and 5.77% for benznidazole and nifurtimox, respectively. The proposed methodology can be considered sensitive, simple, robust, accurate, and green.Universidad Nacional de La Plata (UNLP) - Facultad de Ciencias Exacta

AntVideoRecord: Autonomous system to capture the locomotor activity of leafcutter ants

The leafcutter ants (LCA) are considered plague in a great part of the American continent, causing great damage in production fields. Knowing the locomotion and foraging rhythm in LCA on a continuous basis would imply a significant advance for ecological studies, fundamentally of animal behavior. However, studying the forage rhythm of LCA in the field involves a significant human effort. This also adds a risk of subjective results due to the operator fatigue. In this work a new development named ‘AntVideoRecord’ is proposed to address this issue. This device is a low-cost autonomous system that records videos of the LCA path in a fixed position. The device can be easily reproduced using the freely accessible source code provided. The evaluation of this novel device was successful because it has exceeded all the basic requirements in the field: record continuously for at least seven days, withstand high and low temperatures, capture acceptable videos during the day and night, and have a simple configuration protocol by mobile devices and laptops. It was possible to confirm the correct operation of the device, being able to record more than 1900 h in the field at different climate conditions and times of the day.Fil: Sabattini, Julian Alberto. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Reta, Juan Manuel. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias; ArgentinaFil: Bugnon, Leandro Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional; ArgentinaFil: Cerrudo, Juan Ignacio. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias; ArgentinaFil: Sabattini, Rafael Alberto. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias; ArgentinaFil: Peñalva, Albano. Universidad Nacional de Entre Ríos. Facultad de Ciencias Agropecuarias; ArgentinaFil: Bollazzi, Martín. Universidad de la República; UruguayFil: Paz, Martin Omar. No especifíca;Fil: Sturniolo, F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional; Argentin

Development of an ionic liquid-based dispersive liquid–liquid microextraction method for the determination of nifurtimox and benznidazole in human plasma

Dispersive ionic liquid–liquid microextraction combined with liquid chromatography and UV detection was used for the determination of two antichagasic drugs in human plasma: nifurtimox and benznidazole. The effects of experimental parameters on extraction efficiency—the type and volume of ionic liquid and disperser solvent, pH, nature and concentration of salt, and the time for centrifugation and extraction—were investigated and optimized. Matrix effects were detected and thus the standard addition method was used for quantification. This microextraction procedure yielded significant improvements over those previously reported in the literature and has several advantages, including high inter-day reproducibility (relative standard deviation=1.02% and 3.66% for nifurtimox and benznidazole, respectively), extremely low detection limits (15.7 ng mL −1 and 26.5 ng mL −1 for nifurtimox and benznidazole, respectively), and minimal amounts of sample and extraction solvent required. Recoveries were high (98.0% and 79.8% for nifurtimox and benznidazole, respectively). The proposed methodology offers the advantage of highly satisfactory performance in addition to being inexpensive, simple, and fast in the extraction and preconcentration of these antichagasic drugs from human-plasma samples, with these characteristics being consistent with the practicability requirements in current clinical research or within the context of therapeutic monitoring.Facultad de Ciencias Exacta

Solvatochromic parameters of imidazolium-, hydroxyammonium-, pyridinium- and phosphonium-based room temperature ionic liquids

Solvatochromic solvent parameters of different room temperature ionic liquids based on the imidazolium, hydroxyammonium, pyridinium and phosphonium cations, namely 1-butyl-3-methyl imidazolium hexafluorophosphate, 1-hexyl-3-methyl imidazolium hexafluorophosphate, 1-octyl-3-methyl imidazolium hexafluorophosphate, 1-octyl-3-methyl imidazolium tetrafluoroborate, N-octylpyridinium tetrafluoroborate, 2-hydroxyethylammonium formate, 2-hydroxypropylammonium formate, trihexyl-(tetradecyl)phosphonium chloride, trihexyl-(tetradecyl)phosphonium bromide, trihexyl-(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imide and trihexyl-(tetradecyl)phosphonium dicyanamide were determined at 25 °C using UV-Vis spectroscopy. Specifically, we have measured the Kamlet-Taft parameters: α (hydrogen-bond donor acidity), β (hydrogen-bond acceptor basicity), π∗(dipolarity/polarizability) and the Reichardt's normalized polarity parameter, ET N. In previous works, we employed the Solvation Parameter Model to predict the partition coefficients for compounds of biological and pharmacological interest and to elucidate the chemical interactions involved in the partition process of different probe molecules between water and different types of ionic liquids. In this work, we have used the obtained solvatochromic solvent parameters to explain and understand the relative magnitudes of the chemical interactions obtained with the solvation parameter model.Fil: Padró, Juan Manuel. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Reta, Mario Roberto. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Development of a dispersive liquid-liquid microextraction technique for the analysis of aryloxyphenoxy-propionate herbicides in soy-based foods

In this work, an ionic liquid–dispersive liquid-liquid microextraction (IL-DLLME) method combined with liquid chromatography and diode-array detection (DAD) was used for the determination of four aryloxyphenoxy-propionate herbicides (fenoxaprop-p-ethyl, quizalofop-p-tefuryl, propaquizafop and haloxyfop-p-methyl) in two soy-based foods (soy milk and soy sauce) was used. For this purpose, the phosphonium-based room temperature ionic liquid (trihexyl(tetradecyl)phosphonium bistriflamide) was used as the extractant. The effect of the experimental parameters on extraction efficiency such as type of disperser solvent, disperser solvent/ ionic liquid volumes ratio, pH, nature and concentration of salt in the aqueous phase, sample volume, and centrifugation and extraction times were investigated and optimized. Since matrix effects were detected, the standard addition method was used for quantification. Under the optimized conditions, the proposed sample preparation method coupled to high performance liquid chromatography-diode array detection (HPLC-DAD) had a satisfactory performance to determine the four herbicides in soy sauce and soy milk. The enrichment factors ranged from 18 to 43 and recovery factors from 25 to 66%. Although the recoveries were not high because of the presence of organic solvent in the sample preparation step, the inter-day reproducibility was 8.4% or less, depending on the analyte, the limits of detection (S/N = 3) were obtained in the range of 0.12–0.34 mg L− 1, the limits of quantification (S/N = 10) between 0.36 and 1.04 mg L− 1, and linear ranges from LOQs to 9.26 mg L− 1. Finally, the IL-DLLME methodology is inexpensive, simple, fast, and environmentally friendly for the determination of the studied herbicides in soy sauce and soy milk. This study constitutes the first application of an IL-DLLME methodology to aryloxyphenoxy-propionate herbicides analysis in commercial soy-derived foods.Fil: Lubomirsky, Ester. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; ArgentinaFil: Padró, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; ArgentinaFil: Reta, Mario Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentin

Partition coefficients of organic compounds between water and imidazolium-, pyridinium-, and phosphonium-based ionic liquids

The partition coefficients, P IL/w, of several compounds, some of them of biological and pharmacological interest, between water and room-temperature ionic liquids based on the imidazolium, pyridinium, and phosphonium cations, namely 1-octyl-3-methylimidazolium hexafluorophosphate, N-octylpyridinium tetrafluorophosphate, trihexyl(tetradecyl)phosphonium chloride, trihexyl(tetradecyl)phosphonium bromide, trihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imide, and trihexyl(tetradecyl)phosphonium dicyanamide, were accurately measured. In this way, we extended our database of partition coefficients in room-temperature ionic liquids previously reported. We employed the solvation parameter model with different probe molecules (the training set) to elucidate the chemical interactions involved in the partition process and discussed the most relevant differences among the three types of ionic liquids. The multiparametric equations obtained with the aforementioned model were used to predict the partition coefficients for compounds (the test set) not present in the training set, most being of biological and pharmacological interest. An excellent agreement between calculated and experimental log P IL/w values was obtained. Thus, the obtained equations can be used to predict, a priori, the extraction efficiency for any compound using these ionic liquids as extraction solvents in liquid-liquid extractions.Fil: Padró, Juan Manuel. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química; ArgentinaFil: Pellegrino Vidal, Rocio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química; ArgentinaFil: Reta, Mario Roberto. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química; Argentin

Diseño y simulación de un microinductor planar para un sensor telemétrico de presión intraocular

Motivación: Los microinductores permiten integrar la transmisión inalámbrica de energía en múltiples aplicaciones como sensores y actuadores en el campo biomédico. El uso de EF para el diseño de los microinductores permite considerar las restricciones geométricas y materiales utilizados por las técnicas de micro fabricación. Métodos: Se utilizan modelos 3D numéricos en EF junto con modelos circuitales para el análisis y diseño de una bobina de sección cuadrada. El modelo circuital considera la bobina de cobre depositada sobre un sustrato de silicio cubierta con una película aislante de dióxido de silicio. Los parámetros del modelo son la inductancia, la resistencia del conductor, la capacitancia parásita, y la resistencia del aislante. En el modelo numérico, la geometría consiste en el inductor en forma de espiral rodeado de aire. Las ecuaciones del modelo en EF son las ecuaciones de continuidad y magnetostática donde σ es la conductividad eléctrica, μ es la permeabilidad magnética, A es el vector potencial magnético, V el potencial eléctrico y Je el vector densidad de corriente generada externamente. Resultados: Se comparan los resultados obtenidos de inductancia a partir del modelo circuital con el numérico. Se realizan 3 diseños diferentes de microbobinas para optimizar el tamaño y la tecnología de micro fabricación.Fil: Pérez, María Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Reta, Juan Manuel. Universidad Nacional de Entre Ríos; ArgentinaFil: Guarnieri, Fabio Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones en Métodos Computacionales. Universidad Nacional del Litoral. Centro de Investigaciones en Métodos Computacionales; Argentin

Analysis of non-polar heterocyclic aromatic amines in beefburguers by using microwave-assisted extraction and dispersive liquid–ionic liquid microextraction

A new sample preparation procedure to determine six heterocyclic aromatic amines (3-Amino-1,4-dimethyl-5H-pirido[4,3-b]indole, 3-Amino-1-methyl-5H-pirido[4,3-b]indole, 2-amino-1-methyl-6-phenylimidazo-[4,5-b]pyridine, 2-amino-9H-pyrido-[2,3-b] indole, 2-amino-3-methyl-9H-pyrido-[2,3-b] indole and 2-Amino-1,6-dimethylimidazo [4,5-b]-pyridine) in cooked beefburguers by using a combination of microwave-assisted solvent extraction and dispersive liquid–liquid microextraction with an ionic liquid generated in situ was used. The optimized microwave extraction procedure consisted of a clean-up step with n-heptane and a subsequent dissolution step in basic media to desorb the analytes from the matrix. Next, an aqueous solution of the ionic liquid 1-octyl-3-methylimidazolium tetrafluorborate and sodium hexafluorphosphate was added and a water-insoluble 1-octyl-3-methylimidazolium hexafluorphosphate was formed within the matrix sample. The amines were analyzed by liquid chromatography with fluorescence and diode-array detection by using a typical C18 column. Peak identities were confirmed by absorbance spectral matching. Repeatability (RSD%) between 5.4% and 10.9%, enrichment factors between 19 and 30, limits of detection between 0.35 and 2.4 ng mL−1 and recoveries between 69% and 100% were achieved. The extraction methodology is simple, rapid (about 40 min/sample) cheap and green since small amounts of non-toxic solvents are necessary.Fil: Agudelo Mesa, Leidy Bibiana. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Padro, Juan Manuel. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Reta, Mario Roberto. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin