Open Access. Powered by Scholars. Published by Universities.®

Chemistry Commons

Open Access. Powered by Scholars. Published by Universities.®

PDF

Validation

Discipline
Institution
Publication Year
Publication
Publication Type

Articles 1 - 28 of 28

Full-Text Articles in Chemistry

Development And Validation Of A Liquid Chromatography-Tandem Mass Spectrometry Method For The Determination Of Temozolomide In Mouse Brain Tissue, Raghavi Kakarla, Kimberly Yacoub, Rebecca L. Bearden, Aimin Zhou, Sanjib Mukherjee, Frank Y. Shan, Baochuan Guo Apr 2023

Development And Validation Of A Liquid Chromatography-Tandem Mass Spectrometry Method For The Determination Of Temozolomide In Mouse Brain Tissue, Raghavi Kakarla, Kimberly Yacoub, Rebecca L. Bearden, Aimin Zhou, Sanjib Mukherjee, Frank Y. Shan, Baochuan Guo

Chemistry Faculty Publications

Temozolomide is a Food and Drug Administration-approved anticancer drug that has poor drug delivery via oral or intravenous routes. A potential strategy to combat this problem is investigating alternative routes of administration, requiring quantitation of the drug in the brain tissues by liquid chromatography-mass spectrometry. However, current methods used to extract the drug from brain tissues resulted in poor recovery and substantial matrix effects. Herein, we reported a new two-step extraction method that involves the use of Proteinase K to lyse tumor tissues to efficiently release the drug, followed by ethanol protein precipitation. The extracts were then separated on a …


Chromatographic Profile Of Major Whey Proteins In Some Dairy Beverages Based On Milk Serum, Doina Prodan, Miuta Filip, Mihaela Vlassa, Marioara Moldovan, Rahela Carpa Jan 2022

Chromatographic Profile Of Major Whey Proteins In Some Dairy Beverages Based On Milk Serum, Doina Prodan, Miuta Filip, Mihaela Vlassa, Marioara Moldovan, Rahela Carpa

Turkish Journal of Chemistry

The aim of this study was the determination of chromatographic profiles of major whey proteins (WP): α-lactalbumin (α-La), β-lactoglobulin A and B, (β-Lg A and B), bovine serum albumin (BSA) in dairy beverages based on Zonar milk serum. The studied WP were separated by high-performance liquid chromatography (HPLC) on Aeris XB-C18 column using gradient elution with 0.1% trifluoroacetic acid (TFA) in water and 0.1% TFA in 80% acetonitrile, at 214 nm detection. The HPLC method was validated for system suitability, selectivity/specificity, linearity (R2 ≥ 0.996), precision (RSD% ≤ 2.01), trueness (recovery 96.29%-102.08%), sensitivity (limits of quantification (LOQ) 1.35-10.08 μg/mL), …


Development And Validation Of A New Rp-Hplc Method For Organic Explosive Compounds, Sali̇h Murat Ünsal, Emre Erkan Jan 2022

Development And Validation Of A New Rp-Hplc Method For Organic Explosive Compounds, Sali̇h Murat Ünsal, Emre Erkan

Turkish Journal of Chemistry

A new RP-HPLC method was developed and validated to achieve the separation and quantification of the organic explosive compounds such as pentaerythritol tetranitrate (PETN), 1-methyl-2,4,6-trinitro toluen (TNT), picric acid, 1,3,5,7-tetrazocine (HMX), cyclorimethylenetrinitramine (RDX), 2,4,6 Tri nitro phenyl methyl nitramine (Tetryl), 1-methyl-2,4-dinitro toluen (DNT), ethylene glycol dinitrate (EGDN), and trinitroglycerine (TNG) in this study. The mobile phase composition (IPA percentage in water) and the flow rate was optimized for the separation of the organic explosive compounds. Theoretical plate number (N), capacity factor (k'), resolution (Rs) were used to determine the optimum chromatographic conditions. The most favorable conditions were detected as 22% …


The Application Of Qnmr For The Determination Of Rosuvastatin In Tablet Form, Gökhan Di̇kmen, Okan Uslu Jan 2021

The Application Of Qnmr For The Determination Of Rosuvastatin In Tablet Form, Gökhan Di̇kmen, Okan Uslu

Turkish Journal of Chemistry

In this study, quantative nuclear magnetic resonance (qNMR) method was used to determine the content of rosuvastatin in tablet. Linearity, range, limit of detection (LOD), limit of quantification (LOQ), accuracy, and precision were determined in validation study of rosuvastatin. Furthermore, validation study of rosuvastatin was performed with high performance liquid chromatography (HPLC). Uncertainties of qNMR and HPLC methods were determined using per EURACHEM/CITAC Guide CG 4 (3th edition), quantifying uncertainty in analytical measurement. qNMR and HPLC methods were linear in the ranges of 0.10 - 5.00 mg/mL and 0.001 - 0.0995 mg/mL, respectively and these lineraties indicate very good linearity …


Characterization Of Modern Ammunition And Background Profiles: A Novel Approach And Probabilistic Interpretation Of Inorganic Gunshot Residue, Korina Layli Menking-Hoggatt Jan 2021

Characterization Of Modern Ammunition And Background Profiles: A Novel Approach And Probabilistic Interpretation Of Inorganic Gunshot Residue, Korina Layli Menking-Hoggatt

Graduate Theses, Dissertations, and Problem Reports

Gunshot residue (GSR) can provide essential clues in gun-related investigations. The standard practice for GSR analysis uses SEM-EDS, with the capability for single particle elemental and morphological analysis. However, the method is time-consuming and based on categorical classification models without considering case circumstances. Therefore, complementary and more encompassing methods are needed to improve evidence interpretation of modern ammunition. This research aims to fill these demands by developing standard materials and alternative methods to characterize and interpret IGSR.

This study developed primer GSR (pGSR) standards from sixty discharged primers that were fully characterized by three techniques. The number of GSR particles, …


Development And Validation Of An Hplc Method For Determination Of Rofecoxib In Bovine Serum Albumin Microspheres, Esra Demi̇rtürk, Emi̇rhan Nemutlu, Selma Şahi̇n, Levent Öner Jan 2020

Development And Validation Of An Hplc Method For Determination Of Rofecoxib In Bovine Serum Albumin Microspheres, Esra Demi̇rtürk, Emi̇rhan Nemutlu, Selma Şahi̇n, Levent Öner

Turkish Journal of Chemistry

A simple and reliable HPLC method was developed and validated for determination of rofecoxib in bovine serum albumin microsphere. The analyses were performed on a C18 column (150 x 4.6 mm, 5 μm particle size) at room temperature with UV detection at 272 nm. The mobile phase was composed of acetonitrile-0.1% o-phosphoric acid solution in water (1:1, v/v) mixture, and flow rate was set to 1 mL/min. The method was validated according to the international guidelines with respect to stability, linearity range, limit of quantitation and detection, precision, accuracy, specificity, and robustness. The detection and quantification limit of the method …


Using A Balloon-Launched Unmanned Glider To Validate Real-Time Wrf Modeling, Travis J. Schuyler, S. M. Iman Gohari, Gary Pundsack, Donald Berchoff, Marcelo I. Guzman Apr 2019

Using A Balloon-Launched Unmanned Glider To Validate Real-Time Wrf Modeling, Travis J. Schuyler, S. M. Iman Gohari, Gary Pundsack, Donald Berchoff, Marcelo I. Guzman

Chemistry Faculty Publications

The use of small unmanned aerial systems (sUAS) for meteorological measurements has expanded significantly in recent years. SUAS are efficient platforms for collecting data with high resolution in both space and time, providing opportunities for enhanced atmospheric sampling. Furthermore, advances in mesoscale weather research and forecasting (WRF) modeling and graphical processing unit (GPU) computing have enabled high resolution weather modeling. In this manuscript, a balloon-launched unmanned glider, complete with a suite of sensors to measure atmospheric temperature, pressure, and relative humidity, is deployed for validation of real-time weather models. This work demonstrates the usefulness of sUAS for validating and improving …


Determination Of N-Acetylcysteine In The Presence Of Ciprofloxacin Or Levofloxacin In Microparticulate Dry Powder Inhalers, Yağmur Akdağ Çayli, Selma Şahi̇n, Emi̇rhan Nemutlu, Levent Öner Jan 2019

Determination Of N-Acetylcysteine In The Presence Of Ciprofloxacin Or Levofloxacin In Microparticulate Dry Powder Inhalers, Yağmur Akdağ Çayli, Selma Şahi̇n, Emi̇rhan Nemutlu, Levent Öner

Turkish Journal of Chemistry

A fast and easy method was validated for simultaneous determination of ciprofloxacin hydrochloride monohydrate (CP), levofloxacin hemihydrate (LV), and N-acetylcysteine (NAC) in samples. The analysis was performed on a C$_{18}$ column (250 x 4.6 mm, 5 μm) (Inertsil ODS-3V) using an isocratic elution method with a mobile phase composed of 25 mM KH$_{2}$PO$_{4}$ (pH 3.0) and methanol (72:28, v/v) at a flow rate of 1 mL/min. UV detection was performed at 214 nm for NAC and 293 nm for CP and LV. The method was validated for linearity, accuracy, precision (repeatability and reproducibility), specificity, sensitivity, and stability. The calibration study …


Global Stratospheric Measurements Of The Isotopologues Of Methane From The Atmospheric Chemistry Experiment Fourier Transform Spectrometer, Eric M. Buzan, Chris A. Beale, Chris. D. Boone, Peter F. Bernath Jan 2016

Global Stratospheric Measurements Of The Isotopologues Of Methane From The Atmospheric Chemistry Experiment Fourier Transform Spectrometer, Eric M. Buzan, Chris A. Beale, Chris. D. Boone, Peter F. Bernath

Chemistry & Biochemistry Faculty Publications

This paper presents an analysis of observations of methane and its two major isotopologues, CH3D and 13CH4, from the Atmospheric Chemistry Experiment (ACE) satellite between 2004 and 2013. Additionally, atmospheric methane chemistry is modeled using the Whole Atmospheric Community Climate Model (WACCM). ACE retrievals of methane extend from 6 km for all isotopologues to 75 km for 12CH4, 35 km for CH3D, and 50 km for 13CH4. While total methane concentrations retrieved from ACE agree well with the model, values of δD-CH4 and δ13C-CH …


Mipas Imk/Iaa Cfc-11 (Ccl3f) And Cfc-12 (Ccl2f2) Measurements: Accuracy, Precision And Long-Term Stability, E. Eckert, A. Laeng, S. Lossow, S. Kellmann, G. Stiller, T. Von Clarmann, N. Glatthor, M. Hopfner, M. Kiefer, H. Oelhaf, P. F. Bernath Jan 2016

Mipas Imk/Iaa Cfc-11 (Ccl3f) And Cfc-12 (Ccl2f2) Measurements: Accuracy, Precision And Long-Term Stability, E. Eckert, A. Laeng, S. Lossow, S. Kellmann, G. Stiller, T. Von Clarmann, N. Glatthor, M. Hopfner, M. Kiefer, H. Oelhaf, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

Profiles of CFC-11 (CCl3F) and CFC-12 (CCl2F2) of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) aboard the European satellite Envisat have been retrieved from versions MIPAS/4.61 to MI-PAS/4.62 and MIPAS/5.02 to MIPAS/5.06 level-1b data using the scientific level-2 processor run by Karlsruhe Institute of Technology (KIT), Institute of Meteorology and Climate Research (IMK) and Consejo Superior de Investigaciones Cientificas (CSIC), Instituto de Astrofisica de Andalucia (IAA). These profiles have been compared to measurements taken by the balloon-borne cryosampler, Mark IV (MkIV) and MIPAS-Balloon (MIPAS-B), the airborne MIPAS-STRatospheric aircraft (MIPAS-STR), the satellite-borne Atmospheric Chemistry …


Upper Tropospheric Water Vapour Variability At High Latitudes- Part 1: Influence Of The Annular Modes, Christopher E. Sioris, Jason Zou, David A. Plummer, Chris D. Boone, C. Thomas Mcelroy, Patrick E. Sheese, Omid Moeini, Peter F. Bernath Jan 2016

Upper Tropospheric Water Vapour Variability At High Latitudes- Part 1: Influence Of The Annular Modes, Christopher E. Sioris, Jason Zou, David A. Plummer, Chris D. Boone, C. Thomas Mcelroy, Patrick E. Sheese, Omid Moeini, Peter F. Bernath

Chemistry & Biochemistry Faculty Publications

Seasonal and monthly zonal medians of water vapour in the upper troposphere and lower stratosphere (UTLS) are calculated for both Atmospheric Chemistry Experiment (ACE) instruments for the northern and southern high-latitude regions (60-90° N and 60-90°S). Chosen for the purpose of observing high-latitude processes, the ACE orbit provides sampling of both regions in 8 of 12 months of the year, with coverage in all seasons. The ACE water vapour sensors, namely MAESTRO (Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation) and the Fourier Transform Spectrometer (ACE-FTS) are currently the only satellite instruments that can probe from …


Satellite Observations Of Stratospheric Hydrogen Flouride And Comparisons With Slimcat Calculations, Jeremy J. Harrison, Martyn P. Chipperfield, Christopher D. Boone, Sandip S. Dhomse, Peter F. Bernath, Lucien Froidevaux Jan 2016

Satellite Observations Of Stratospheric Hydrogen Flouride And Comparisons With Slimcat Calculations, Jeremy J. Harrison, Martyn P. Chipperfield, Christopher D. Boone, Sandip S. Dhomse, Peter F. Bernath, Lucien Froidevaux

Chemistry & Biochemistry Faculty Publications

The vast majority of emissions of fluorine-containing molecules are anthropogenic in nature, e.g. chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (HFCs). Many of these fluorine-containing species deplete stratospheric ozone and are regulated by the Montreal Protocol. Once in the atmosphere they slowly degrade, ultimately leading to the formation of hydrogen fluoride (HF), the dominant reservoir of stratospheric fluorine due to its extreme stability. Monitoring the growth of stratospheric HF is therefore an important marker for the success of the Montreal Protocol. We report the comparison of global distributions and trends of HF measured in the Earth's atmosphere by the satellite remote-sensing …


Relative Drifts And Biases Between Six Ozone Limb Satellite Measurements From The Last Decade, N. Rahpoe, M. Weber, A. V. Rozanov, K. Weigel, H. Bovensmann, J. P. Burrows, A. Laeng, G. Stiller, T. Von Clarmann, E. Kyrölä, V. F. Sofieva, J. Tamminen, K. Walker, D. Degenstein, A. E. Bourassa, R. Hargreaves, P. Bernath, J. Urban, D. P. Murtagh Jan 2015

Relative Drifts And Biases Between Six Ozone Limb Satellite Measurements From The Last Decade, N. Rahpoe, M. Weber, A. V. Rozanov, K. Weigel, H. Bovensmann, J. P. Burrows, A. Laeng, G. Stiller, T. Von Clarmann, E. Kyrölä, V. F. Sofieva, J. Tamminen, K. Walker, D. Degenstein, A. E. Bourassa, R. Hargreaves, P. Bernath, J. Urban, D. P. Murtagh

Chemistry & Biochemistry Faculty Publications

As part of European Space Agency's (ESA) climate change initiative, high vertical resolution ozone profiles from three instruments all aboard ESA's Envisat (GOMOS, MIPAS, SCIAMACHY) and ESA's third party missions (OSIRIS, SMR, ACE-FTS) are to be combined in order to create an essential climate variable data record for the last decade. A prerequisite before combining data is the examination of differences and drifts between the data sets. In this paper, we present a detailed analysis of ozone profile differences based on pairwise collocated measurements, including the evolution of the differences with time. Such a diagnosis is helpful to identify strengths …


The Development Of New Concepts For Assessing Reproductive Toxicity Applicable To Large Scale Toxicological Programmes, S. Bremer, C. Pellizzer, S. Hoffmann, T. Seidle, T. Hartung Dec 2014

The Development Of New Concepts For Assessing Reproductive Toxicity Applicable To Large Scale Toxicological Programmes, S. Bremer, C. Pellizzer, S. Hoffmann, T. Seidle, T. Hartung

Troy Seidle, PhD

Large scale toxicological testing programmes which are currently ongoing such as the new European chemical legislation REACH require the development of new integrated testing strategies rather than applying traditional testing schemes to thousands of chemicals. The current practice of requiring in vivo testing for every possible adverse effect endanger the success of these programmes due (i) to limited testing facilities and sufficient capacity of scientific/technical knowledge for reproductive toxicity; (ii) an unacceptable number of laboratory animals involved (iii) an intolerable number of chemicals classified as false positive.

A key aspect of the implementation of new testing strategies is the determination …


Discovery Of Novel Serum Biomarkers For Diagnosing And Staging Alzheimer's Disease, Dipti Jigar Shah Jun 2014

Discovery Of Novel Serum Biomarkers For Diagnosing And Staging Alzheimer's Disease, Dipti Jigar Shah

Theses and Dissertations

Discovery of Novel Serum Biomarkers for Diagnosing and Staging Alzheimer’s DiseaseDipti Jigar ShahDepartment of Chemistry and Biochemistry, BYUDoctor of PhilosophyAlzheimer’s disease (AD) is an untreatable neurologic disease affecting more than 5 million Americans, most over 60 years of age. Protein plaques and neurofibrillary tangles typify AD brain pathology and are thought to cause the progressive dementia and brain shrinkage observed in AD. Currently there are no methods to diagnose the disease at a time before damage becomes irreversible.Biochemical tests for AD using cerebrospinal fluid analysis or neuroimaging are not yet sufficiently sensitive and specific, and they are invasive. This points …


Drift Corrected Trends And Periodic Variations In Mipas Imk/Iaa Ozone Measurements, E. Eckert, T. Von Clarmann, M. Kiefer, G. P. Stiller, S. Lossow, N. Glatthor, D. A. Degenstein, L. Froidevaux, S. Godin-Beekmann, T. Leblanc, S. Mcdermid, M. Pastel, W. Steinbrcht, D.P.J. Swart, K. A. Walker, P. F. Bernath Jan 2014

Drift Corrected Trends And Periodic Variations In Mipas Imk/Iaa Ozone Measurements, E. Eckert, T. Von Clarmann, M. Kiefer, G. P. Stiller, S. Lossow, N. Glatthor, D. A. Degenstein, L. Froidevaux, S. Godin-Beekmann, T. Leblanc, S. Mcdermid, M. Pastel, W. Steinbrcht, D.P.J. Swart, K. A. Walker, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

Drifts, trends and periodic variations were calculated from monthly zonally averaged ozone profiles. The ozone profiles were derived from level-1b data of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) by means of the scientific level-2 processor run by the Karlsruhe Institute of Technology (KIT), Institute for Meteorology and Climate Research (IMK). All trend and drift analyses were performed using a multilinear parametric trend model which includes a linear term, several harmonics with period lengths from 3 to 24 months and the quasi-biennial oscillation (QBO). Drifts at 2-sigma significance level were mainly negative for ozone relative to Aura MLS and …


Derivation Of Tropospheric Methane From Tccon Ch4 And Hf Total Column Observations, K. M. Saad, D. Wunch, P. Bernath, C. Boone, B. Connor, N. M. Deutscher, D.W.T. Griffith, R. Kivi, J. Notholt, C. Roehl, M. Schneider, V. Sherlock, P. O. Wennberg Jan 2014

Derivation Of Tropospheric Methane From Tccon Ch4 And Hf Total Column Observations, K. M. Saad, D. Wunch, P. Bernath, C. Boone, B. Connor, N. M. Deutscher, D.W.T. Griffith, R. Kivi, J. Notholt, C. Roehl, M. Schneider, V. Sherlock, P. O. Wennberg

Chemistry & Biochemistry Faculty Publications

The Total Carbon Column Observing Network (TCCON) is a global ground-based network of Fourier transform spectrometers that produce precise measurements of column-averaged dry-air mole fractions of atmospheric methane (CH4). Temporal variability in the total column of CH4 due to stratospheric dynamics obscures fluctuations and trends driven by tropospheric transport and local surface fluxes that are critical for understanding CH4 sources and sinks. We reduce the contribution of stratospheric variability from the total column average by subtracting an estimate of the stratospheric CH4 derived from simultaneous measurements of hydrogen fluoride (HF). HF provides a proxy for …


A Novel Algorithm For Validating Peptide Identification From A Shotgun Proteomics Search Engine, Ling Jian, Xinnan Niu, Zhonghang Xia, Parimal Samir, Chiranthani Sumanasekera, Zheng Mu, Jennifer L. Jennings, Kristen L. Hoek, Tara Allos, Leigh M. Howard, Kathryn M. Edwards, P. Anthony Weil, Andrew J. Link Feb 2013

A Novel Algorithm For Validating Peptide Identification From A Shotgun Proteomics Search Engine, Ling Jian, Xinnan Niu, Zhonghang Xia, Parimal Samir, Chiranthani Sumanasekera, Zheng Mu, Jennifer L. Jennings, Kristen L. Hoek, Tara Allos, Leigh M. Howard, Kathryn M. Edwards, P. Anthony Weil, Andrew J. Link

Chemistry Faculty Research

Liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) has revolutionized the proteomics analysis of complexes, cells, and tissues. In a typical proteomic analysis, the tandem mass spectra from a LC–MS/MS experiment are assigned to a peptide by a search engine that compares the experimental MS/MS peptide data to theoretical peptide sequences in a protein database. The peptide spectra matches are then used to infer a list of identified proteins in the original sample. However, the search engines often fail to distinguish between correct and incorrect peptides assignments. In this study, we designed and implemented a novel algorithm called De-Noise to …


Optimization Of A Gas Chromatography--Mass Spectrometry Method Using Chemometric Techniques For The Determination Of Ezetimibe In Human Plasma, Ebru Uçaktürk, Nuran Özaltin Jan 2013

Optimization Of A Gas Chromatography--Mass Spectrometry Method Using Chemometric Techniques For The Determination Of Ezetimibe In Human Plasma, Ebru Uçaktürk, Nuran Özaltin

Turkish Journal of Chemistry

A new, rapid, and sensitive gas chromatography--mass spectrometry (GC-MS) method was developed for the determination of ezetimibe (EZE) in human plasma. EZE was derivatized prior to GC-MS analysis. Various derivatization techniques such as acetylation, methylation, and silylation were tried. EZE was extracted from plasma with high recovery (94.39%--97.57%) using methyl tertbutyl ether and carbonate buffer (pH 9). Chromatographic conditions were optimized using chemometric methods. In the first step, optimization with factorial design, chromatographic variables (initial and final column temperature, oven ramp rate, and flow rate of gas) were screened to select important variables for the retention of EZE. In the …


Hci And Cio Profiles Inside The Antarctic Vortex As Observed By Smiles In November 2009: Comparisons With Mls And Ace-Fts Instruments, T. Sugita, Y. Kasai, Y. Terao, S. Hayashida, G. L. Manney, W. H. Daffer, H. Sagawa, M. Suzuki, M. Shiotani, K. A. Walker, C. D. Boone, P. F. Bernath Jan 2013

Hci And Cio Profiles Inside The Antarctic Vortex As Observed By Smiles In November 2009: Comparisons With Mls And Ace-Fts Instruments, T. Sugita, Y. Kasai, Y. Terao, S. Hayashida, G. L. Manney, W. H. Daffer, H. Sagawa, M. Suzuki, M. Shiotani, K. A. Walker, C. D. Boone, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

We present vertical profiles of hydrogen chloride (HCl) and chlorine monoxide (ClO) as observed by the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the International Space Station (ISS) inside the Antarctic vortex on 19-24 November 2009. The SMILES HCl value reveals 2.8-3.1 ppbv between 450K and 500K levels in potential temperature (PT). The high value of HCl is highlighted since it is suggested that HCl is a main component of the total inorganic chlorine Cly, defined as Cly similar or equal to HCl + ClO + chlorine nitrate ClONO2, inside the Antarctic vortex in spring, owing …


Observations Of Peroxyacetyl Nitrate (Pan) In The Upper Troposphere By The Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (Ace-Fts), K. A. Tereszchuk, D. P. Moore, J. J. Harrison, C. D. Boone, M. Park, J. J. Remedios, W. J. Randel, P. F. Bernath Jan 2013

Observations Of Peroxyacetyl Nitrate (Pan) In The Upper Troposphere By The Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (Ace-Fts), K. A. Tereszchuk, D. P. Moore, J. J. Harrison, C. D. Boone, M. Park, J. J. Remedios, W. J. Randel, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

Peroxyacetyl nitrate (CH3CO·O2NO2, abbreviated as PAN) is a trace molecular species present in the troposphere and lower stratosphere due primarily to pollution from fuel combustion and the pyrogenic outflows from biomass burning. In the lower troposphere, PAN has a relatively short lifetime and is principally destroyed within a few hours through thermolysis, but it can act as a reservoir and carrier of NOx in the colder temperatures of the upper troposphere, where UV photolysis becomes the dominant loss mechanism. Pyroconvective updrafts from large biomass burning events can inject PAN into the upper troposphere …


Investigation Of Co, C2h6 And Aerosols In A Boreal Fire Plume Over Eastern Canada During Bortas 2011 Using Ground- And Satellite-Based Observations And Model Simulations, D. Griffin, K. A. Walker, J. E. Franklin, M. Parrington, C. Whaley, J. Hopper, J. R. Drummond, P. I. Palmer, K. Strong, T. J. Duck, P. F. Bernath Jan 2013

Investigation Of Co, C2h6 And Aerosols In A Boreal Fire Plume Over Eastern Canada During Bortas 2011 Using Ground- And Satellite-Based Observations And Model Simulations, D. Griffin, K. A. Walker, J. E. Franklin, M. Parrington, C. Whaley, J. Hopper, J. R. Drummond, P. I. Palmer, K. Strong, T. J. Duck, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

We present the results of total column measurements of CO, C2H6 and fine-mode aerosol optical depth (AOD) during the "Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites" (BORTAS-B) campaign over eastern Canada. Ground-based observations, using Fourier transform spectrometers (FTSs) and sun photometers, were carried out in July and August 2011. These measurements were taken in Halifax, Nova Scotia, which is an ideal location to monitor the outflow of boreal fires from North America, and also in Toronto, Ontario. Measurements of fine-mode AOD enhancements were …


Equipment Qualification Of Ion Mobility Spectrometry And Method Development And Validation For Pharmaceutical Equipment Cleaning Validation, Amy Lee Heiser Dec 2012

Equipment Qualification Of Ion Mobility Spectrometry And Method Development And Validation For Pharmaceutical Equipment Cleaning Validation, Amy Lee Heiser

Masters Theses

Ion mobility spectrometry (IMS) instrumentation has been identified as a suitable technology for the detection and reporting of drug product and detergent residues from pharmaceutical manufacturing equipment. Ion mobility is not a new technology, but is entering the field of cleaning validation because of tightened requirements from the US Food and Drug Administration (FDA).

The purpose of this thesis is to outline a practical implementation of the analytical technique, Ion Mobility Spectrometry in a cleaning validation program. Ion Mobility Spectrometry (IMS) is fast and specific for the analysis of small organic molecules and has been gaining popularity in the pharmaceutical …


Simultaneous Determination Of Sitagliptin And Metformin In Pharmaceutical Preparations By Capillary Zone Electrophoresis And Its Application To Human Plasma Analysis, Mohamed Salim, Nahed El-Enany, Fathalah Belal, Mohomad Walash, Gabor Patonay Jul 2012

Simultaneous Determination Of Sitagliptin And Metformin In Pharmaceutical Preparations By Capillary Zone Electrophoresis And Its Application To Human Plasma Analysis, Mohamed Salim, Nahed El-Enany, Fathalah Belal, Mohomad Walash, Gabor Patonay

Chemistry Faculty Publications

A novel, quick, reliable and simple capillary zone electrophoresis CZE method was developed and validated for the simultaneous determination of sitagliptin (SG) and metformin (MF) in pharmaceutical preparations. Separation was carried out in fused silica capillary (50.0 cm total length and 43.0 cm effective length, 49 μm i.d.) by applying a potential of 15 KV (positive polarity) and a running buffer containing 60 mM phosphate buffer at pH 4.0 with UV detection at 203 nm. The samples were injected hydrodynamically for 3 s at 0.5 psi and the temperature of the capillary cartridge was kept at 25 °C. Phenformin was …


Technical Note: A Trace Gas Climatology Derived From The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (Ace-Fts) Data Set, A. Jones, K. A. Walker, J. J. Jin, J. R. Taylor, C. D. Boone, P. F. Bernath, S. Brohede, G. L. Manney, S. Mcleod, R. Hughes, W. H. Daffer Jan 2012

Technical Note: A Trace Gas Climatology Derived From The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (Ace-Fts) Data Set, A. Jones, K. A. Walker, J. J. Jin, J. R. Taylor, C. D. Boone, P. F. Bernath, S. Brohede, G. L. Manney, S. Mcleod, R. Hughes, W. H. Daffer

Chemistry & Biochemistry Faculty Publications

The Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS) aboard the Canadian satellite SCISAT (launched in August 2003) was designed to investigate the composition of the upper troposphere, stratosphere, and mesosphere. ACE-FTS utilizes solar occultation to measure temperature and pressure as well as vertical profiles of over thirty chemical species including O3, H2O, CH4, N2O, CO, NO, NO2, N2O5, HNO3, HCl, ClONO2, CCl3F, CCl2F2, and HF. Global coverage for each species is obtained approximately over a three month …


Development And Validation Of A Rapid Multi-Class Method For The Confirmation Of Fourteen Prohibited Medicinal Additives In Pig And Poultry Compound Feed By Liquid Chromatography Tandem Mass Spectrometry, Mark Cronly, Patrice Behan, Barry Foley, Liam Regan, Marella Gallagher, Sean Earley, Paula Shearan, Edward Malone Dec 2010

Development And Validation Of A Rapid Multi-Class Method For The Confirmation Of Fourteen Prohibited Medicinal Additives In Pig And Poultry Compound Feed By Liquid Chromatography Tandem Mass Spectrometry, Mark Cronly, Patrice Behan, Barry Foley, Liam Regan, Marella Gallagher, Sean Earley, Paula Shearan, Edward Malone

Articles

A confirmatory method has been developed to allow for the analysis of fourteen prohibited medicinal additives in pig and poultry compound feed. These compounds are prohibited for use as feed additives although some are still authorised for use in medicated feed. Feed samples are extracted by acetonitrile with addition of sodium sulphate. The extracts undergo a hexane wash to aid with sample purification. The extracts are then evaporated to dryness and reconstituted in initial mobile phase. The samples undergo an ultracentrifugation step prior to injection onto the LC-MS/MS system and are analysed in a run time of 26 minutes. The …


Rapid Multi-Class Multi-Residue Method For The Confirmation Of Chloramphenicol And Eleven Nitroimidazoles In Milk And Honey By Liquid Chromatography Tandem Mass Spectrometry, Mark Cronly, Patrice Behan, Barry Foley, Liam Regan, Sheila Martin, Michael Doyle, Edward Malone Jun 2010

Rapid Multi-Class Multi-Residue Method For The Confirmation Of Chloramphenicol And Eleven Nitroimidazoles In Milk And Honey By Liquid Chromatography Tandem Mass Spectrometry, Mark Cronly, Patrice Behan, Barry Foley, Liam Regan, Sheila Martin, Michael Doyle, Edward Malone

Articles

A confirmatory method has been developed to allow for the analysis of eleven nitroimidazoles and also chloramphenicol in milk and honey samples. These compounds are classified as A6 compounds in annex IV of council regulation 2377/90 and therefore prohibited for the use in animal husbandry. Milk samples are extracted by acetonitrile with addition of NaCl, while honey samples are first dissolved in water before a similar extraction. Honey extracts undergo a hexane wash to remove impurities. Both milk and honey extracts are evaporated to dryness and reconstituted in initial mobile phase. These are then injected onto an LC-MS/MS system and …


Performance Comparison Between Monolithic C18 And Conventional C18 Particle-Packed Columns In The Liquid Chromatographic Determination Of Propranolol Hcl, Sami El Deeb, Hermann Watzig Jan 2006

Performance Comparison Between Monolithic C18 And Conventional C18 Particle-Packed Columns In The Liquid Chromatographic Determination Of Propranolol Hcl, Sami El Deeb, Hermann Watzig

Turkish Journal of Chemistry

Monolithic and conventional particle-packed columns were applied for the determination of propranolol hydrochloride in the presence of its 2 main degradation products, 3-(1-naphthyloxy)-propane-1,2- diol and 4-isopropyl-1,7-bis-(1-naphthyloxy)-4-azaheptane-2,6-diol. The separations were investigated on monolithic columns at flow rates from 1 to 9 mL/min. Fast and efficient separation was obtained by monolithic columns. The analysis time was decreased by about 5-fold on monolithic columns at a flow rate of 4 mL/min, while maintaining sufficient resolution between propranolol and its degradation products. The method was validated using a set of 3 monolithic columns and compared to a conventional (Superspher) C18 column. The precision for …