Development of Needle Trap Technology for On-Site Determinations: Active and Passive Sampling

This study presents a thorough evaluation of new prototypes of extended tip needle trap devices (NT), as well as their application to in situ sampling of biological emissions and active/passive on-site sampling of indoor air. A new NT prototype was constructed with a side hole above the sorbent and an extended tip that fits inside the restriction of the narrow neck liner to increase desorption efficiency.New prototype needles were initially packed with divinylbenzene particles at SGE Analytical Science for the purpose of studying biogenic emissions of pine trees. Prior to their final application, they were evaluated in terms of robustness after multiple use (n ˃ 10), as well as amount extracted of volatile organic compounds (VOCs). An ANOVA test for all the probes showed that at a 95 % level of confidence, there were not statistical differences observed among the 9 NTs tested. In addition, the needles were also packed in laboratory with synthesized highly cross linked PDMS as a frit to immobilize carboxen (Car) particles for spot sampling. For passive sampling, the needles were packed with Car particles embedded in PDMS in order to simplify calculations in passive mode. The use of NTs as spot samplers, as well as a passive sampler under controlled conditions in the laboratoryyielded a relative standard deviation of less than 15 %. Finally, a new, reusable and readily deployable pen-like diffusive sampler for needle traps (PDS-NT) was built and tested. Application of the PDS-NT in combination with NT-spot sampling towards the analysis of indoor air in a polymer synthesis laboratory showed good agreement between both techniques for the analyte studied, yielding averages of 0.03 ng/mL and 0.025 ng/mL of toluene, respectively.NSERC Industrial Research Chair || NSERC IRCPJ/184412-10 05016

Comparación de la composición química y de la actividad biológica de los aceites esenciales de lippia alba (mill.) n.e.br., obtenidos variando las condiciones de extracción y secado

Se compararon la composición química y la actividad biológica de aceites esenciales (AEs) de Lippia alba, obtenidos bajo diferentes condiciones de extracción (hidrodestilación asistida por la radiación de microondas, MWHD) y secado de la planta (a la sombra). Los AEs fueron caracterizados por GC-MS. Los resultados mostraron similitudes cualitativas entre los aceites evaluados y diferencias cuantitativas significativas, en términos de su composición química y rendimiento ( por ciento p/p). El aceite esencial que presentó el mayor rendimiento y contenido de limoneno y carvona (componentes principales) fue el obtenido después de 4 días de secado y un tiempo de extracción de 45 min. El AE que presentó la más alta toxicidad contra Artemia franciscana fue el obtenido después de 3 días de secado y un tiempo de extracción de 60 minutos

Comparación de la composición química y de la actividad biológica de los aceites esenciales de lippia alba (mill.) n.e.br., obtenidos variando las condiciones de extracción y secado

Se compararon la composición química y la actividad biológica de aceites esenciales (AEs) de Lippia alba, obtenidos bajo diferentes condiciones de extracción (hidrodestilación asistida por la radiación de microondas, MWHD) y secado de la planta (a la sombra). Los AEs fueron caracterizados por GC-MS. Los resultados mostraron similitudes cualitativas entre los aceites evaluados y diferencias cuantitativas significativas, en términos de su composición química y rendimiento ( por ciento p/p). El aceite esencial que presentó el mayor rendimiento y contenido de limoneno y carvona (componentes principales) fue el obtenido después de 4 días de secado y un tiempo de extracción de 45 min. El AE que presentó la más alta toxicidad contra Artemia franciscana fue el obtenido después de 3 días de secado y un tiempo de extracción de 60 minutos

Composición química y evaluación de la actividad antiherpética in vitro de aceites esenciales de Lippia alba (Mill) N.E. Brown y sus componentes mayoritarios

RESUMEN Introducción: Lippia  alba (Mill) N.E. Brown es una planta aromática perteneciente a la familia Verbenaceae, ampliamente usada en Suramérica y Norteamérica como  infusión contra la hipertensión, problemas digestivos, náuseas y resfriados.Objetivo: En el presente estudio, se evaluó  la actividad antiviral in vitro frente al Herpesvirus Humano Tipo 1 (HSV-1), de veinte aceites esenciales de L. alba y, diez de sus componentes mayoritarios.Metodología: La actividad antiviral in vitro fue evaluada empleando la técnica modificada, de titulación del punto final (EPTT). Los aceites esenciales, de plantas de L. alba recolectadas de diferentes regiones del país, fueron obtenidos por hidrodestilación asistida con radiación de microondas (MWHD).  Se determinó por cromatografía de gases–espectrometría de masas (GC-MS), la composición química, de los veinte aceites esenciales de L. alba, identificándose dos quimiotipos: citral y carvona.Resultados y conclusiones: Los aceites quimiotipo carvona, BC1 y CA2, mostraron actividad antiherpética in vitro, moderada sobre monocapa de células HeLa infectadas,  con valores de Rf de 1x101,5, en concentraciones, de 250μg/mL y 125μg/mL, respectivamente. Los controles  positivos, sulfato de heparina y aciclovir, redujeron el titulo viral con valores de Rf, en orden,  de 1x102 y 1x104.  Ninguno de los monoterpenos evaluados mostró actividad contra el  HSV-1. Salud UIS 2010; 42:   Palabras clave: Lippia alba (Mill) N.E. Brown, herpesvirus humano 1, agentes antivirales, aceite esencial, verbenaceae ABSTRACT Introduction: Lippia alba (Mill.) N.E. Brown is an aromatic shrub belonging to the Verbenaceae family, which is widely used all over South and Central America as an infusion against, hypertension, digestive troubles, nausea and cold.Objective: The antiviral activity in vitro against Herpesvirus 1, Human (HSV-1) of twenty essential oils of L. alba and ten of its components were evaluated.Methodology: The antiviral activity was determined using a modified end-point titration technique (EPPT). The essential oils from L. alba collected in different regions of Colombia were obtained by microwave-assisted hydrodistillation (MWHD). Their chemical compositions were determined by GC and GC/MS.  Two chemotypes were distinguished, characterized by carvone and citral as main constituents.Results and conclusions: Carvone chemotype oils BC1 and CA2 were found to be moderate antiviral activity over infected confluent monolayers of HeLa cells with Rf value of 1x101,5 at a concentration of 250μg/mL and 125μg/mL, respectively. Heparin sodium salt and acyclovir were used as positive controls and showed Rf values of 1x102 and 1x104, respectively.  None of monoterpenes tested showed antiviral activity against HSV-1. Salud UIS 2010; 42:   Keywords: Lippia alba (Mill) N.E. Brown, herpesvirus 1, human, essential oil, antiviral agents, verbenacea

Composición química y evaluación de la actividad antiherpética in vitro de aceites esenciales de Lippia alba (Mill) N.E. Brown y sus componentes mayoritarios

RESUMEN Introducción: Lippia  alba (Mill) N.E. Brown es una planta aromática perteneciente a la familia Verbenaceae, ampliamente usada en Suramérica y Norteamérica como  infusión contra la hipertensión, problemas digestivos, náuseas y resfriados.Objetivo: En el presente estudio, se evaluó  la actividad antiviral in vitro frente al Herpesvirus Humano Tipo 1 (HSV-1), de veinte aceites esenciales de L. alba y, diez de sus componentes mayoritarios.Metodología: La actividad antiviral in vitro fue evaluada empleando la técnica modificada, de titulación del punto final (EPTT). Los aceites esenciales, de plantas de L. alba recolectadas de diferentes regiones del país, fueron obtenidos por hidrodestilación asistida con radiación de microondas (MWHD).  Se determinó por cromatografía de gases–espectrometría de masas (GC-MS), la composición química, de los veinte aceites esenciales de L. alba, identificándose dos quimiotipos: citral y carvona.Resultados y conclusiones: Los aceites quimiotipo carvona, BC1 y CA2, mostraron actividad antiherpética in vitro, moderada sobre monocapa de células HeLa infectadas,  con valores de Rf de 1x101,5, en concentraciones, de 250μg/mL y 125μg/mL, respectivamente. Los controles  positivos, sulfato de heparina y aciclovir, redujeron el titulo viral con valores de Rf, en orden,  de 1x102 y 1x104.  Ninguno de los monoterpenos evaluados mostró actividad contra el  HSV-1. Salud UIS 2010; 42:   Palabras clave: Lippia alba (Mill) N.E. Brown, herpesvirus humano 1, agentes antivirales, aceite esencial, verbenaceae ABSTRACT Introduction: Lippia alba (Mill.) N.E. Brown is an aromatic shrub belonging to the Verbenaceae family, which is widely used all over South and Central America as an infusion against, hypertension, digestive troubles, nausea and cold.Objective: The antiviral activity in vitro against Herpesvirus 1, Human (HSV-1) of twenty essential oils of L. alba and ten of its components were evaluated.Methodology: The antiviral activity was determined using a modified end-point titration technique (EPPT). The essential oils from L. alba collected in different regions of Colombia were obtained by microwave-assisted hydrodistillation (MWHD). Their chemical compositions were determined by GC and GC/MS.  Two chemotypes were distinguished, characterized by carvone and citral as main constituents.Results and conclusions: Carvone chemotype oils BC1 and CA2 were found to be moderate antiviral activity over infected confluent monolayers of HeLa cells with Rf value of 1x101,5 at a concentration of 250μg/mL and 125μg/mL, respectively. Heparin sodium salt and acyclovir were used as positive controls and showed Rf values of 1x102 and 1x104, respectively.  None of monoterpenes tested showed antiviral activity against HSV-1. Salud UIS 2010; 42:   Keywords: Lippia alba (Mill) N.E. Brown, herpesvirus 1, human, essential oil, antiviral agents, verbenacea

Quantitative analysis of biofluid spots by coated blade spray mass spectrometry, a new approach to rapid screening

This study demonstrates the quantitative capabilities of coated blade spray (CBS) mass spectrometry (MS) for the concomitant analysis of multiple target substances in biofluid spots. In CBS-MS the analytes present in a given sample are first isolated and enriched in the thin coating of the CBS device. After a quick rinsing of the blade surface, as to remove remaining matrix, the analytes are quickly desorbed with the help of a solvent and then directly electrosprayed into the MS analyzer. Diverse pain management drugs, controlled substances, and therapeutic medications were successfully determined using only 10 µL of biofluid, with limits of quantitation in the low/sub ng·mL−1 level attained within 7 minutes.Thermo Scientific Natural Sciences and Engineering Research Council (NSERC) of Canada - Industrial Research Chair program Authors are very grateful with Pfizer Canada Inc., Merck Canada Inc., Quebec Consortium for Drug Discovery (CQDM), Brain Canada, and Ontario Brain Institute for the grant “Solid phase microextraction-based integrated platform for untargeted and targeted in vivo brain studies

Rapid determination of immunosuppressive drug concentrations in whole blood by coated blade spray-tandem mass spectrometry (CBS-MS/MS)

The final publication is available at Elsevier via https://dx.doi.org/10.1016/j.aca.2017.10.016 © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/Coated Blade Spray (CBS) is a technology that efficiently integrates sample preparation and direct coupling to mass spectrometry (MS) on a single device. In this article, we present CBS-tandem mass spectrometry (CBS-MS/MS) as a novel tool for the rapid and simultaneous determination of four commonly used immunosuppressive drugs (ISDs) in whole blood: tacrolimus (TAC) and cyclosporine-A (CycA), which are calcineurin inhibitors; and sirolimus (SIR) and everolimus (EVR), which are both mTOR (mechanistic target of rapamycin) inhibitors. Given that CBS extracts via free concentration, analytes that are largely bound to plasma proteins or red blood cells provide considerably lower extraction recovery rates. Therefore, we defy the solventless philosophy of SPME-based techniques, like CBS, by performing the analyte-enrichment step via direct immersion in a solvent-modified matrix. The assay was linear within the evaluated range of concentrations (between 1 and 100 ng/mL for EVR/SIR/TAC and 10–1000 ng/mL for CycA), and the limits of quantification were determined to be 10 ng/mL for CycA and 1 ng/mL for EVR/SIR/TAC. Good accuracy (87–119%) and linearity (r2 ≥ 0.99) were attained over the evaluated range for all ISDs. Interassay imprecision (CV) determined from incurred sample reanalysis was ≤10% for all ISDs. Our method was validated using Liquichek™ whole blood immunosuppressant quality control (QC) standards purchased from Bio-Rad. Concentrations determined by CBS-MS/MS were inside the range specified by Bio-Rad and within 15% of the expected mean value for all ISDs at all QC levels. Furthermore, the effect of different hematocrit levels (20, 45, and 70%) in the entire calibration range was carefully studied. No statistical differences (RSD ≤ 7%) in the calibration curve slopes of ISDs in blood were observed. CBS offers a simpler workflow than that of traditional methods; it eliminates the need for chromatographic separation and provides a clean extract that allows for long-term MS instrumental operation with minimal maintenance. Additionally, because CBS integrates all analytical steps into one device, it eliminates the risk of instrumental carry-over and can be used as a low-cost disposable device for sample preparation and analysis. Fully-automated sample preparation simplifies the method and allows for total analysis times as short as 3 min with turn-around times of less than 90 min.Natural Sciences and Engineering Research Council of Canada (NSERC) Industrial Research Chair progra

Seismicity and seismotectonics for the Northern sector of the Algeciras Fault System, Eastern Cordillera, Colombia

Al Sistema de Fallas de Algeciras (SFA), se le han asignado cuatro sismos históricos desde finales del siglo XVIII, que en términos de magnitud recalculada desde análisis macrosísmicos tuvieron una magnitud M>6.5. Uno de estos, el del 9 de febrero de 1967, fue registrado instrumentalmente con Mw 7.2. En este trabajo se realizó un estudio del sector norte de este sistema de fallas entre los 3° y 4°N. Entre el 31 de octubre de 2016 y el 18 de julio de 2018, se presentaron cuatro sismos con Mw>4.8, que la Red Sismológica Nacional de Colombia (RSNC) localizó en el municipio de Colombia, departamento del Huila, asignándolos a fallas del SFA. Luego, en diciembre 24 de 2019, se presentó un sismo con Mw 6.0, que se asignó a la Falla Algeciras perteneciente al SFA en el departamento del Meta. En esta investigación se encontró que los sismos de la región de Colombia se produjeron en las fallas Altamira y Nazareth, las cuales son fallas inversas en un contexto tectono - estratigráfico diferente al SFA. El SFA al norte de los 3°N define en esta región el piedemonte llanero. Para las fallas Altamira y Nazareth, los mecanismos focales indicaron fallas inversas, mientras que en la región de Mesetas estos mecanismos obedecieron a fallas transcurrentes concordantes con el SFA. Dada la alta generación de sismos con Mw>5.0 en estas fallas en un lapso inferior a 10 años, se establece que su potencial sismogénico contribuye de manera importante a la amenaza sísmica del centro y el suroccidente de Colombia, sin embargo, en este trabajo se encontró además que la denominada Falla Algeciras, principal componente del SFA por la literatura, está segmentada y no es continua, por lo que se debe revaluar su potencial sismogénico.From the late seventeenth century, the Algeciras Fault System (AFS) has been attributed to four historical earthquakes whose magnitude recalculated from macroseismic scale analysis had a magnitude of M>6.5. One of these, that of February 9th, 1967, was instrumentally registered with a magnitude of Mw 7.2. In this work, a study was carried out in the Northern sector of this fault system between 3° and 4°N. Between October 31st, 2016, and July 18th, 2018, four earthquakes with Mw>4.8, were located by the National Seismological Network of Colombia (NSNC) in the municipality of Colombia, department of Huila, were attributed by them to the AFS. Then, on December 24th, 2019, an earthquake with Mw 6.0 was attributed by the NSCS to the Algeciras fault in the department of Meta. This fault is part of the AFS. In accordance with this research, the earthquakes in the region of Colombia occurred in the Altamira and Nazareth Faults, which are reverse faults in a tectono-stratigraphic framework different from the AFS. The AFS toward north of 3°N defines the Llanos Foothills in this region. For the Altamira and Nazareth Faults, the earthquake focal mechanisms indicated inverse faults, while in the Mesetas region its earthquake focal mechanisms indicated right lateral strike - slip faults consistent with the AFS. Because of the high generation of earthquakes with Mw>5.0 for these faults in a period of less than 10 years, here it is established that their seismogenic potential contributes in a very important way to the seismic hazard of central and southwestern Colombia. However, in this work it was also found that the so-called Algeciras Fault, the main component of the SFA in the literature, is segmented and not continuous, so its seismogenic potential should be reassessed