Online solid phase extraction-HPLC-ICP-MS system for mercury and methylmercury preconcentration using functionalised carbon nanotubes for their determination in dietary supplements

A hyphenated system was developed for Hg(ii) and methylmercury (MeHg) preconcentration and speciation analysis by the online coupling of solid phase extraction (SPE), high performance liquid chromatography (HPLC) and inductively coupled plasma mass spectrometry (ICP-MS). Both analytes, Hg(ii) and MeHg, were preconcentrated on a microcolumn filled with multiwalled carbon nanotubes (MWCNTs) functionalised with poly-l-methionine (polymet-MWCNTs). During the method development the sorbent material was carefully studied and the solid phase extraction conditions were optimised. An enrichment factor of 190 for Hg(ii) and MeHg was obtained when 20 mL of sample was passed through the microcolumn. For the chromatographic separation, a mobile phase composed of a ternary mixture of 0.5% formic acid + 0.2% 2-mercaptoethanol + 20% methanol was used. Separation of both mercurial species was accomplished in ∼10 min on a 250 mm C18 column. The detection limits of the SPE-HPLC-ICP-MS method were 15 ng L−1 for Hg(ii) and 17 ng L−1 for MeHg. The relative standard deviations of peak area for 5 ng L−1 of each Hg species were below 5%. Recoveries of Hg(ii) and MeHg were never less than 93%. For checking the accuracy, BCR 643-tuna fish and TORT-3 lobster hepatopancreas certificate reference materials were analysed. Mercury species were determined in spiked fish oil-based dietary supplements and Antarctic water.Fil: Londonio, Juan Agustín. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín. Instituto de Investigación en Ingeniería Ambiental; ArgentinaFil: Hasuoka, Paul Emir. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Pacheco, Pablo Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Gil, Raul Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Smichowski, Patricia Nora. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentin

Selenomethionine administration decreases the oxidative stress induced by post mortem ischemia in the heart, liver and kidneys of rats

Selenium is an essential element in human and animal metabolism integrated into the catalytic site of glutathione peroxidase (GPX1), an antioxidant enzyme that protects cells from damage caused by reactive oxygen species (ROS). Oxidative stress refers the imbalance between ROS and antioxidant defense systems. It generates alterations of DNA, proteins and lipid peroxidation. The imbalance occurs particularly during ischemia and lack of postmortem perfusion. This mechanism is of relevance in transplant organs, affecting their survival. The aim of this research is to evaluate the effect of seleno-methionine (SeMet) as a protective agent against postmortem ischemia injury in transplant organs. Wistar rats were orally administered with SeMet. After sacrifice, liver, heart and kidney samples were collected at different postmortem intervals (PMIs). SeMet administration produced a significant increase of Se concentration in the liver (65%, p < 0.001), heart (40%, p < 0.01) and kidneys (45%, p < 0.05). Levels of the oxidative stress marker malondialdehyde (MDA) decreased significantly compared to control in the heart (0.21 ± 0.04 vs. 0.12 ± 0.02 mmol g−1) and kidneys (0.41 ± 0.02 vs. 0.24 ± 0.03 mmol g−1) in a PMI of 1–12 h (p < 0.01). After SeMet administration for 21 days, a significant increase in GPX1 activity was observed in the liver (80%, p < 0.001), kidneys (74%, p < 0.01) and heart (35%, p < 0.05). SeMet administration to rats significantly decreased the oxidative stress in the heart, liver and kidneys of rats generated by postmortem ischemia.Fil: Hasuoka, Paul Emir. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Pérez Iglesias, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Teves, Mauricio Roberto. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; ArgentinaFil: Kaplan, Marcos Manuel. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ferrúa, Nelson Hugo. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; ArgentinaFil: Pacheco, Pablo Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentin

Arsenic species uptake and translocation in Elodea canadensis

The capacity of Elodea canadensis to phytofiltrate arsenic species from water was evaluated. Plants were adapted to tap water and supplemented with 15 and 250 µg L −1 of As. Inorganic arsenic species (As III, As V), and organic arsenic compounds: monomethylarsonate (MMA) and dimethylarsinate (DMA) were analyzed. Sampling was carried out at different times after exposure in culture water and plant organs. Plants exposed to 15 µg L −1 of As concentration showed no significant difference on As concentration (95% confidence level) in their organs compared to controls. When plants were exposed to 250 µg L −1 of As concentration, a significant increase of As concentration in plant organs was observed. After 1 h exposure, plants reduce 63.16% the As concentration in the culture water, with a bioaccumulation factor (BF) of 4.3. Under these conditions, E. canadensis accumulate As V in roots and do not translocate it to stems (transfer factor <1). MMA was determined in stems and leaves. E. canadensis effectively phytofiltrate As from tap water of a city located in an arsenic endemic area from concentrations of 36 µg L −1 to undetectable levels (10 ng L −1 ).Fil: Picco, Patricio. Universidad Tecnológica Nacional. Facultad Regional Trenque Lauquen; ArgentinaFil: Hasuoka, Paul Emir. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Verni, Ernesto Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Savio, Marianela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; ArgentinaFil: Pacheco, Pablo Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentin

Arsenic speciation analysis in cow's milk and plant-based imitation milks by HPLC-ICP-MS

Imitation milks based on vegetables have become relevant in recent years as a substitute for cow´s milk. Total and inorganic content of arsenic (As) determination in food is of utmost importance due to toxicological concerns. This study aimed to (1) optimize and validate a methodology for speciation analysis using anion exchange high performance liquid chromatography coupled to plasma mass spectrometry and (2) analyze the arsenic content in milk and imitation milks.Determination of As (III) and As (V) was done following a simple and innovative treatment, which consisted on the dilution of a small volume of sample in mobile phase and further filtration. Furthermore, acid microdigestion for total As determination with small amounts of acid and sample was optimized. The detection limits of the method ranged from 0.2 to 0.7 µg L-1. Regarding to arsenic content we found that imitation milks based on peanuts and nuts presented the lowest inorganic As content (between 1.7 to 1 µg L-1) whereas the highest values were found in imitations based on soy, rice and vetch (27.3, 13 and 8 µg L-1, respectively). The cow’s milk presented intermediate levels of inorganic As (4 µg L-1). Also, almond- and quinoa-based imitation milks showed inorganic As values below detection limits, so these imitation milks may be the safest to consume with respect to arsenic contentFil: Permigiani, Isis Sabrina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Vallejo Azar, Nicolás Karim. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Hasuoka, Paul Emir. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Gil, Raul Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Romero, Maria Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

Speciation analysis of atmospheric arsenic adsorbed on pollen and aerobiological samples before and during COVID-19 pandemic period

Atmospheric arsenic species adsorbed on pollen samples were extracted and determined by liquid chromatography coupled to inductively coupled plasma mass spectrometry (LC-ICP- MS). The optimised extraction method required acetone 1% (v v−1), 15 minutes ultrasonic bath and centrifugation. As (III) and As (V) concentrations ranged from 0.08 to 0.62 µg g−1, and from 0.33 to 0.89 µg g−1 respectively. The method reach a LOD and LOQ of 0.01 and 0.04 µg g−1 for As (III); and 0.01 and 0.06 µg g−1 for As (V), respectively analysing 0.05 g of pollen. Precision as relative standard deviation (RSD %) corresponded to 4.1% (n = 10). A standard addition method was performed for validation with quantitative As recoveries in a range of 81.39 to 104.81%. In order to define the As pollution source, a pre-pandemic and pandemic study was performed with significant variations in total As concentration in aerobiological samples, suggesting that traffic increases atmospheric As concentration.Fil: Escudero, Daniela Rocío. Universidad Nacional de San Luis; ArgentinaFil: Isaguirre, Andrea Celeste. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Moyano, Mario Franco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: HASUOKA, PAUL EMIR. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Pacheco, Pablo Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Moglia, Marta Matilde. Universidad Nacional de San Luis; Argentin