Program Development for Computer Simulation and Analysis for Multiplex Chromatography

In this report, the programs developed for the analysis of simulated data in multiplex chromatography are written in the ASYST language. The integration of the program modules into a menu-driven, user-friendly prototype program is outlined. The program is developed to allow for flexibility and easy upgrading of the code. This report examines the calculation procedures potentially useful in multiplex chromatography. Analysis of the mutliplex chromatograms is done by three mathematical methods, Cross-Correlation, Hadamard Transform and Fast Fourier Transform. The effects of experimental length/chromatogram length and decision sequences on correlation noise present in a single chromatogram, are discussed. As the number of data points increases, n, the improvement of the signal-to-noise ratio in the resulting single chromatograms is found to be a little less than the theoretical rate of (n)0.5. A non-random decision sequence is discovered to introduce drift and noise into the multiplex chromatogram. The influence of electronic white noise and electronic drift in the experimental data (multiplex chromatogram) on the resulting single chromatograms is explored. As electronic white noise increases, the signal-to-noise ratio in the resulting single chromatogram decreases. Electronic drift also introduces noise. Discussion of the best methods for given experimental conditions is based upon the signal-to-noise ratio in the resulting single chromatograms. Cross-Correlation is theoretically the fastest method but is greatly influenced by drift. Hadamard Transform is slower than Cross-Correlation but is not effected by drift. Fast Fourier Transform has the best signal-to noise ratio in the resulting single chromatogram but the peak magnitudes are not always reflective of the real heights. Fast Fourier Transform is slow but if written in machine language, is faster than Cross-Correlation or Hadamard Transform written in the ASYST language

Development of a Carbon Mesh Supported Thin Film Microextraction Membrane As a Means to Lower the Detection Limits of Benchtop and Portable GC/MS Instrumentation

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.5b04008.In this work, a durable and easy to handle thin film microextraction (TFME) device is reported. The membrane is comprised of poly(divinylbenzene) (DVB) resin particles suspended in a high-density polydimethylsiloxane (PDMS) glue, which is spread onto a carbon fiber mesh. The currently presented membrane was shown to exhibit a substantially lesser amount of siloxane bleed during thermal desorption, while providing a statistically similar extraction efficiency toward a broad spectrum of analytes varying in polarity when compared to an unsupported DVB/PDMS membrane of similar shape and size which was prepared with previously published methods. With the use of hand-portable GC-TMS instrumentation, membranes cut with dimensions 40 mm long by 4.85 mm wide and 40 ± 5 μm thick (per side) were shown to extract 21.2, 19.8, 18.5, 18,4, 26.8, and 23.7 times the amount of 2,4 dichlorophenol, 2,4,6 trichlorophenol, phorate D10, fonofos, chloropyrifos, and parathion, respectively, within 15 min from a 10 ppb aqueous solution as compared to a 65 μm DVB/PDMS solid phase microextraction (SPME) fiber. A portable high volume desorption module prototype was also evaluated and shown to be appropriate for the desorption of analytes with a volatility equal to or lesser than benzene when employed in conjunction with TFME membranes. Indeed, the coupling of these TFME devices to hand-portable gas chromatography toroidial ion trap mass spectrometry (GC-TMS) instrumentation was shown to push detection limits for these pesticides down to the hundreds of ppt levels, nearing that which can be achieved with benchtop instrumentation. Where these membranes can also be coupled to benchtop instrumentation it is reasonable to assume that detection limits could be pushed down even further. As a final proof of the concept, the first ever, entirely on-site TFME-GC-TMS analysis was performed at a construction impacted lake. Results had indicated the presence of contaminants such as toluene, ethylbenzene, xylene, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, and tris(1-chloro-2-propyl)phosphate, which stood out from other naturally occurring compounds detected.the Natural Sciences and Engineering Research Council of Canada (NSERC

Micelle assisted thin-film solid phase microextraction: a new approach for determination of quaternary ammonium compounds in environmental samples

Determination of quaternary ammonium compounds (QACs) often is considered to be a challenging undertaking owing to secondary interactions of the analytes’ permanently charged quaternary ammonium head or hydrophobic tail with the utilized lab-wares. Here, for the first time, a micelle assisted thin-film solid phase microextraction (TF-SPME) using a zwitterionic detergent 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) as a matrix modifier is introduced as a novel approach for in-laboratory sample preparation of the challenging compounds. The proposed micelle assisted thin-film solid phase microextraction (TF-SPME) method offers suppression/enhancement free electrospray ionization of analytes in mass spectrometric detection, minimal interaction of the micelles with the TF-SPME coating, and chromatographic stationary phase and analysis free of secondary interactions. Moreover, it was found that the matrix modifier has multiple functions; when its concentration is found below the critical micelle concentration (CMC), the matrix modifier primarily act as a surface deactivator; above its CMC, it acts as a stabilizer for QACs. Additionally, shorter equilibrium extraction times in the presence of the modifier demonstrated that micelles also assist in the transfer of analytes from the bulk of the sample to the surface of the coating. The developed micelle assisted TF-SPME protocol using the 96-blade system requires only 30 min of extraction and 15 min of desorption. Together with a conditioning step (15 min), the entire method is 60 min; considering the advantage of using the 96-blade system, if all the blades in the brush are used, the sample preparation time per sample is 0.63 min. Moreover, the recoveries for all analytes with the developed method were found to range within 80.2%- 97.3%; as such, this method can be considered an open bed solid phase extraction. The proposed method was successfully validated using real samples.NSERC Industrial Research Chair || NSERC IRCPJ/184412-10 05016

Numerical simulation and experimental validation of calibrant-loaded extraction phase standardization approach

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/full/10.1021/acs.analchem.6b01802We present the kinetics of calibrant release and analyte uptake between the sample and calibrant-loaded extraction phase, CL-EP with a finite-element analysis (FEA) using COMSOL Multiphysics® software package. Effect of finite and infinite sample volume conditions, as well as various sample environment parameters such as fluid flow velocity, temperature, and presence of a binding matrix component were investigated in detail with the model in relation to the performance of the calibration. The simulation results supported by experimental data demonstrate the suitability of the CL-EP method for analysis of samples with variation of the sample environment parameters. The calibrant-loaded approach can provide both total and free concentrations from a single experiment based on whether the partition coefficient (Kes) value being used is measured in a matrix-matched sample or in a matrix-free sample, respectively. Total concentrations can also be obtained by utilizing CL-EP in combination with external matrix-matched calibrations, which can be employed to automate the sampling process and provide corrections for variations in sample preparation, matrix effects, and detection processes. This approach is also suitable for very small volumes of sample, where addition of an internal standard in the sample is either troublesome or can change the sample characteristics.National Science and Engineering Research Council Ontario Research Fun

Headspace versus Direct Immersion Solid Phase Microextraction in Complex Matrixes: Investigation of Analyte Behavior in Multicomponent Mixtures

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.5b01850This work aims to investigate the behavior of analytes in complex mixtures and matrixes with the use of solid-phase microextraction (SPME). Various factors that influence analyte uptake such as coating chemistry, extraction mode, the physicochemical properties of analytes, and matrix complexity were considered. At first, an aqueous system containing analytes bearing different hydrophobicities, molecular weights, and chemical functionalities was investigated by using commercially available liquid and solid porous coatings. The differences in the mass transfer mechanisms resulted in a more pronounced occurrence of coating saturation in headspace mode. Contrariwise, direct immersion extraction minimizes the occurrence of artifacts related to coating saturation and provides enhanced extraction of polar compounds. In addition, matrix-compatible PDMS-modified solid coatings, characterized by a new morphology that avoids coating fouling, were compared to their nonmodified analogues. The obtained results indicate that PDMS-modified coatings reduce artifacts associated with coating saturation, even in headspace mode. This factor, coupled to their matrix compatibility, make the use of direct SPME very practical as a quantification approach and the best choice for metabolomics studies where wide coverage is intended. To further understand the influence on analyte uptake on a system where additional interactions occur due to matrix components, ex vivo and in vivo sampling conditions were simulated using a starch matrix model, with the aim of mimicking plant-derived materials. Our results corroborate the fact that matrix handling can affect analyte/matrix equilibria, with consequent release of high concentrations of previously bound hydrophobic compounds, potentially leading to coating saturation. Direct immersion SPME limited the occurrence of the artifacts, which confirms the suitability of SPME for in vivo applications. These findings shed light into the implementation of in vivo SPME strategies in quantitative metabolomics studies of complex plant-based systems.The Natural Sciences and Engineering Research Council of Canada (NSERC) Sigma-Aldrich Corporatio

Cinnamaldehyde Characterization as an Antibacterial Agent toward E. coli Metabolic Profile Using 96-Blade Solid-Phase Microextraction Coupled to Liquid Chromatography–Mass Spectrometry

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Proteome Research, 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.jproteome.5b00992Sampling and sample preparation plays an important role in untargeted analysis as it influences final composition of the analyzed extract and consequently reflection of the metabolome. In the current work, mechanism of bactericidal action of cinnamaldehyde (CA) against Escherichia coli (E. coli) during bacteria growth applying high-throughput solid-phase microextraction in direct immersion mode coupled to a high-performance liquid chromatography–mass spectrometry system was investigated. Numerous discriminant metabolites due to CA addition to the bacteria culture were mapped in the E. coli metabolic pathways. We propose new metabolic pathways confirming that CA acts as an oxidative stress agent against E. coli. The results of the current research have successfully demonstrated that CA changes the bacterial metabolism through interactions with different biochemical families such as proteins, nucleic acids, lipids, and carbohydrates, which needs further validation by proteomics and transcriptomics studies. The results presented here show the great potential of the novel approach in drug discovery and food safety.Natural Sciences and Engineering Research Council (NSERC) of Canad

Fantazmaty „Polaka” czyli przemyślenia z obszarów egzystencjalnej filozofii religii

The immediate inspiration for this text is Tomasz Polak's book "System kościelny czyli przewagi pana K" (The Church System or the Advantages of Mr. K). The author analyses in detail how the "system" works, claiming that it has taken over the church from the very beginning of its existence, absorbing the original vitality of the community. The conclusion he reaches is that the "system" is unreformable. In this article I compare T. Polak's basic thought with what Tomasz Węcławski wrote years ago about the church. I emphasize that this is the same person who changed his name due to life circumstances. I try to analyze how far the thinking, the way of argumentation, and finally the formulated conclusions have changed. The key word for these considerations is "phantasm." In this light, the question of God "with me, in me, and over me" dies in the face of the workings of the "church system." The phantasm prevails over man and his living relationship to God. "The Church System or the Advantages of Mr. K", is a very sad story about an individual, even though told in an expert and difficult language. Religion, faith, which someone makes the determinant and meaning of life, is something that from the beginning is doomed to drift towards an unshakeable phantasm, something that, in fact, will never come true, except in the most intimate and private dimension

Direct Coupling of Dispersive Extractions with Magnetic Particles to Mass Spectrometry via Microfluidic Open Interface

Microextraction coupled to mass spectrometry (MS) has great potential in analytical chemistry laboratories operating in a variety of fields. Indeed, microextraction methods directly coupled to MS can be of large value given that they can provide not only analyte extraction and enrichment but also effective sample cleanup. In recent years, the practicality in handling high active surface area, versatility, and environmentally friendly features of magnetic dispersive microextraction technologies has contributed to an explosion in the number of methods and technologies reported in the literature for a wide range of applications. However, to the best of our knowledge, no technology to date has been capable of efficiently merging these two rising concepts in a simple and integrated analytical workflow. In this context, the microfluidic open interface is presented for the direct coupling of dispersive magnetic extraction to mass spectrometry. This technology operates under the concept of a flow-isolated desorption volume, which generates a stagnant droplet open to ambient conditions while continuously feeding the ionization source with solvent by means of the self-aspiration process intrinsic of the electrospray ionization (ESI) interface. To improve the efficiency of the final analytical workflow, a novel dispersive magnetic micro- and nanoparticle extraction protocol for biofluid droplets was developed. The final methodology entailed the dispersion of a small amount of magnetic particles (20-70 μg) in a droplet of biofluid (≤40 μL) for extraction, followed by a particle collection step using a homemade 3D-printed holder containing an embedded rare-earth magnet. In the final step, the holder is set on top of the microfluidic open interface (MOI) for desorption in the isolated droplet. Switching the valve transfers the desorbed analytes to the ESI source in less than 5 s. As proof of concept, the completely new setup was applied to the determination of prohibited substances from phosphate-buffered saline (PBS) and human urine using Fe 2 O 3 magnetic nanoparticles (50 nm) functionalized with C 18 . The limits of quantitation (LOQs) obtained were in the low-ppb range in all cases, and acceptable precision (≤20%) and accuracy (80-120%) were attained. Also, taking advantage of the fast extraction kinetics provided by the radial diffusion associated with small particles, we employed the methodology for the selective extraction of phosphopeptides from 40 μL of tryptic β-casein digest using 70 μg of magnetic Ti-IMAC microparticles. To conclude, the technology and methodology herein presented provided excellent capabilities comparable to those of other solid-phase microextraction (SPME-MS) approaches while dramatically minimizing the amount of sample and sorbent required per analysis, as well as affording significantly fast extraction times due to the enhanced kinetics of extraction.Fil: Tascon, Marcos. University of Waterloo; Canadá. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; ArgentinaFil: Singh, Varoon. University of Waterloo; CanadáFil: Huq, Mohammad. University of Waterloo; CanadáFil: Pawliszyn, Janusz. University of Waterloo; Canad

Mikołaj Bierdiajew jako inspiracja dla filozoficznego myślenia o piekle

In the discussion concerning the understanding of what hell is, the opinion of the Russian philosopher Nikolai Berdyaev is very important. He is strongly opposed to the attempts to rationalize the problem saying that, sooner or later, they breed fear and anxiety. Hell is pure subjectivity, the inability to go beyond the circle of our spirit’s constant torment. Therefore, hell is not related to objectivity. Rather, it is a total confinement, a state of helplessness. It is being imprisoned in time, which has no end, a dream, from which it is impossible to wake up. Thus, it is not the result of God’s decision, a punishment for committed sins. On the contrary, it is the result of choice, being in favor of your own loneliness. Ultimately, it will remain only a creation of our rationalization. Therefore, we must have hope (which perhaps will be false) that hell does not exist.In the discussion concerning the understanding of what hell is, the opinion of the Russian philosopher Nikolai Berdyaev is very important. He is strongly opposed to the attempts to rationalize the problem saying that, sooner or later, they breed fear and anxiety. Hell is pure subjectivity, the inability to go beyond the circle of our spirit’s constant torment. Therefore, hell is not related to objectivity. Rather, it is a total confinement, a state of helplessness. It is being imprisoned in time, which has no end, a dream, from which it is impossible to wake up. Thus, it is not the result of God’s decision, a punishment for committed sins. On the contrary, it is the result of choice, being in favor of your own loneliness. Ultimately, it will remain only a creation of our rationalization. Therefore, we must have hope (which perhaps will be false) that hell does not exist

Direct Coupling of Dispersive Extractions with Magnetic Particles to Mass Spectrometry via Microfluidic Open Interface

Microextraction coupled to mass spectrometry (MS) has great potential in analytical chemistry laboratories operating in a variety of fields. Indeed, microextraction methods directly coupled to MS can be of large value given that they can provide not only analyte extraction and enrichment but also effective sample cleanup. In recent years, the practicality in handling high active surface area, versatility, and environmentally friendly features of magnetic dispersive microextraction technologies has contributed to an explosion in the number of methods and technologies reported in the literature for a wide range of applications. However, to the best of our knowledge, no technology to date has been capable of efficiently merging these two rising concepts in a simple and integrated analytical workflow. In this context, the microfluidic open interface is presented for the direct coupling of dispersive magnetic extraction to mass spectrometry. This technology operates under the concept of a flow-isolated desorption volume, which generates a stagnant droplet open to ambient conditions while continuously feeding the ionization source with solvent by means of the self-aspiration process intrinsic of the electrospray ionization (ESI) interface. To improve the efficiency of the final analytical workflow, a novel dispersive magnetic micro- and nanoparticle extraction protocol for biofluid droplets was developed. The final methodology entailed the dispersion of a small amount of magnetic particles (20-70 μg) in a droplet of biofluid (≤40 μL) for extraction, followed by a particle collection step using a homemade 3D-printed holder containing an embedded rare-earth magnet. In the final step, the holder is set on top of the microfluidic open interface (MOI) for desorption in the isolated droplet. Switching the valve transfers the desorbed analytes to the ESI source in less than 5 s. As proof of concept, the completely new setup was applied to the determination of prohibited substances from phosphate-buffered saline (PBS) and human urine using Fe 2 O 3 magnetic nanoparticles (50 nm) functionalized with C 18 . The limits of quantitation (LOQs) obtained were in the low-ppb range in all cases, and acceptable precision (≤20%) and accuracy (80-120%) were attained. Also, taking advantage of the fast extraction kinetics provided by the radial diffusion associated with small particles, we employed the methodology for the selective extraction of phosphopeptides from 40 μL of tryptic β-casein digest using 70 μg of magnetic Ti-IMAC microparticles. To conclude, the technology and methodology herein presented provided excellent capabilities comparable to those of other solid-phase microextraction (SPME-MS) approaches while dramatically minimizing the amount of sample and sorbent required per analysis, as well as affording significantly fast extraction times due to the enhanced kinetics of extraction.Fil: Tascon, Marcos. University of Waterloo; Canadá. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; ArgentinaFil: Singh, Varoon. University of Waterloo; CanadáFil: Huq, Mohammad. University of Waterloo; CanadáFil: Pawliszyn, Janusz. University of Waterloo; Canad