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

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

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

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

Fast quantitation of opioid isomers in human plasma by differential mobility spectrometry/mass spectrometry via SPME/open-port probe sampling interface

The final publication is available at Elsevier via https://dx.doi.org/10.1016/j.aca.2017.08.023 © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/Mass spectrometry (MS) based quantitative approaches typically require a thorough sample clean-up and a decent chromatographic step in order to achieve needed figures of merit. However, in most cases, such processes are not optimal for urgent assessments and high-throughput determinations. The direct coupling of solid phase microextraction (SPME) to MS has shown great potential to shorten the total sample analysis time of complex matrices, as well as to diminish potential matrix effects and instrument contamination. In this study, we demonstrate the use of the open-port probe (OPP) as a direct and robust sampling interface to couple biocompatible-SPME (Bio-SPME) fibres to MS for the rapid quantitation of opioid isomers (i.e. codeine and hydrocodone) in human plasma. In place of chromatography, a differential mobility spectrometry (DMS) device was implemented to provide the essential selectivity required to quantify these constitutional isomers. Taking advantage of the simplified sample preparation process based on Bio-SPME and the fast separation with DMS-MS coupling via OPP, a high-throughput assay (10–15 s per sample) with limits of detection in the sub-ng/mL range was developed. Succinctly, we demonstrated that by tuning adequate ion mobility separation conditions, SPME-OPP-MS can be employed to quantify non-resolved compounds or those otherwise hindered by co-extracted isobaric interferences without further need of coupling to other separation platforms.SCIEXNatural Sciences and Engineering Research Council (NSERC) of Canad

Biocompatible Solid-Phase Microextraction Nanoelectrospray Ionization: An Unexploited Tool in Bioanalysis

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Analytical Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/acs.analchem.5b03668In recent years, different geometrical configurations of solid-phase microextraction (SPME) have been directly coupled to mass spectrometry, resulting in benefits such as diminishing matrix effects, improvement of detection limits, and considerable enhancement of analysis throughput. Although SPME fibers have been used for years, their potential for quantitative analysis when directly combined with mass spectrometry has not been explored to its full extent. In this study, we present the direct coupling of biocompatible SPME (Bio-SPME) fibers to mass spectrometry via nanoelectrospray ionization (nano-ESI) emitters as a powerful tool for fast quantitative analysis of target analytes in biofluids. Total sample preparation time does not exceed 2 min, and by selecting an appropriate fiber length and sample vessel, sample volumes ranging between 10 and 1500 μL can be used. Despite the short extraction time of the technique, limits of detection in the subnanogram per milliliter with good accuracy (≥90%) and linearity (R2 > 0.999) were attained for all the studied probes in phosphate-buffered saline (PBS), urine, and whole blood. Given that Bio-SPME–nano-ESI efficiently integrates sampling with analyte extraction/enrichment, sample cleanup (including elimination of matrix effects in the form of particles), and ionization, our results demonstrated that it is an advantageous configuration for bioanalytical applications such as therapeutic drug monitoring, doping in sports, and pharmacological studies in various matrixes.the Natural Sciences and Engineering Research Council (NSERC) of Canad

Space-resolved tissue analysis by solid-phase microextraction coupled to high-resolution mass spectrometry via desorption electrospray ionization

It is hard to overstate the tremendous utility of desorption electrospray ionization (DESI) and its various configurations for rapid and high-throughput analyses or spatially resolved imaging of heterogeneous systems. However, there have been few attempts to employ this technique in spatially resolved mode with solid substrates featuring extractive and analyte-enrichment properties. This study documents the development of a platform that combines solid-phase microextraction (SPME) with desorption electrospray ionization mass spectrometry (DESI-MS) for unidimensional investigation of the heterogeneous distribution of compounds in semisolid systems (i.e., depth profiling across the fiber axis), with the ultimate end of employing it for brain tissue analysis. To this end, a DESI interface and a custom holder accommodating SPME probes were built in house, with the latter contributing to reduction of mechanical sources of signal instability. The system was evaluated through the quantitative SPME na reconstruction of the laminar and radial concentration gradients of xenobiotics introduced in multilayer gel arrangements and surrogate brain tissue models. Good quantitative capability was achieved by employing a strategy that combined signal correction via preloading internal standard onto SPME fibers and signal integration in scan-by-scan mode. The proposed technique's suitability for characterizing more complex systems, such as rat brains ex vivo, was also evaluated. The proposed approach allows for fast and noninvasive probing of three-dimensional objects without the need for their slicing, and the space-resolved mode reduces the number of required probe insertions, allowing in vivo applications. We foresee suitability of this setup for examining the spatial patterns of local drug release in the brain and the extent of the resultant physiological responses

Composición química y evaluación de la actividad antiherpética in vitro de aceites esenciales de Lippia alba (Mill) N.E. Brown y sus componentes mayoritarios Chemical Composition and evaluation in vitro of anti-herpetic activity of essential oils from Lippia alba (Mill) NE Brown and the main components

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 1x10(1,5), en concentraciones, de 250 &#956;g/mL y 125 &#956;g/mL, respectivamente. Los controles positivos, sulfato de heparina y aciclovir, redujeron el titulo viral con valores de Rf, en orden, de 1x10² y 1x10(4). Ninguno de los monoterpenos evaluados mostró actividad contra el HSV-1. Salud UIS 2010; 42: 230-239<br>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. 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 1x10(1,5) at a concentration of 250 &#956;g/mL and 125 &#956;g/mL, respectively. Heparin sodium salt and acyclovir were used as positive controls and showed Rf values of 1x10² and 1x10(4), respectively. None of monoterpenes tested showed antiviral activity against HSV-1. Salud UIS 2010; 42: 230-23

High-throughput analysis using non-depletive SPME: challenges and applications to the determination of free and total concentrations in small sample volumes

Abstract In vitro high-throughput non-depletive quantitation of chemicals in biofluids is of growing interest in many areas. Some of the challenges facing researchers include the limited volume of biofluids, rapid and high-throughput sampling requirements, and the lack of reliable methods. Coupled to the above, growing interest in the monitoring of kinetics and dynamics of miniaturized biosystems has spurred the demand for development of novel and revolutionary methodologies for analysis of biofluids. The applicability of solid-phase microextraction (SPME) is investigated as a potential technology to fulfill the aforementioned requirements. As analytes with sufficient diversity in their physicochemical features, nicotine, N,N-Diethyl-meta-toluamide, and diclofenac were selected as test compounds for the study. The objective was to develop methodologies that would allow repeated non-depletive sampling from 96-well plates, using 100 µL of sample. Initially, thin film-SPME was investigated. Results revealed substantial depletion and consequent disruption in the system. Therefore, new ultra-thin coated fibers were developed. The applicability of this device to the described sampling scenario was tested by determining the protein binding of the analytes. Results showed good agreement with rapid equilibrium dialysis. The presented method allows high-throughput analysis using small volumes, enabling fast reliable free and total concentration determinations without disruption of system equilibrium