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    Spectroscopic, structural and DFT study of the responses of carbonylmetal crown ether complexes to alkali metal cations

    Stephenson, G. Richard
    Anson, Christopher E, Creaser, Colin S, Daul, Claude A
    European Journal of Inorganic Chemistry. - 2011///2086–2097
    2011-04-20
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    Title: Spectroscopic, structural and DFT study of the responses of carbonylmetal crown ether complexes to alkali metal cations
    Author: Stephenson, G. Richard
    Contributor: Anson, Christopher E; Creaser, Colin S; Daul, Claude A
    Date: 2011-04-20
    Description: FTIR spectra of tricarbonyl(η⁶-benzo-15-crown-5)chromium(0) (1) in the presence of lithium, sodium and potassium perchlorate salts in methanol show different responses in the Cr–CO vibrational region of the spectrum. Data from the symmetric (νsym) and antisymmetric (νasym) Cr–CO vibrational stretching modes have been analysed by principal component analysis (PCA) to generate a factor score plot that provides a visual representation of these differential responses. X-ray crystallographic data for the sodium perchlorate complex 1·Na⁺ and dimensions from DFT-derived structures of 1·Li⁺, 1·Na⁺ and 1·K⁺ indicate that binding M⁺ in the crown causes electron density and structural changes in the [O(4)–C(9)–C(4)–O(8)]Cr–C(1)=O(1) sections of 1, which vary depending on the nature of the cation. This suggests a mode of action in which Li⁺ associates with a more compact O(4)–C(9)–C(4)–O(8), while Na⁺ and K⁺ differ crucially in the extent of σ and π contributions to their effect on νsym and νasym. A comparison of the FTIR data from 1, tricarbonyl(η⁶-1-phenyl-1-aza-15-crown-5)chromium(0) (2) and tricarbonyl(η⁶-2-phenyl-15-crown-5)chromium(0) (3) with a wider range of cations (NH₄⁺, Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺, Mg²⁺, Ba²⁺) and anions (AcO⁻, BPh₄⁻, Br⁻, C1O₄⁻, I⁻, SCN⁻), showed that 1 and 3 both responded significantly to the different metal cations, but 2 did not. The relative cation differentiation of 1, 2 and 3 was measured using the parameter ΔR(cation), and ratios of ΔN(cation) values [calculated from ΔR(cation)] distinguished different effects in the FTIR spectra of 1 and 3 for different pairs of cations.
    Linked entry: European Journal of Inorganic Chemistry. - 2011///2086–2097
    Host document: European Journal of Inorganic Chemistry
    Identifier: 10.1002/ejic.201001274 (DOI)

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    Direct analysis of oil additives by high-field asymmetric waveform ion mobility spectrometry-mass spectrometry combined with electrospray ionization and desorption electrospray ionization

    Da Costa, Caitlyn, Turner, Matthew A., Reynolds, James C., Whitmarsh, Samuel, Lynch, Tom, Creaser, Colin S.

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    Direct determination of urinary creatinine by reactive-thermal desorption-extractive electrospray-ion mobility-tandem mass spectrometry.

    Devenport, Neil A., Blenkhorn, Daniel J., Weston, Daniel J., Reynolds, James C., Creaser, Colin S.

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    Direct Detection of a Sulfonate Ester Genotoxic Impurity by Atmospheric-Pressure Thermal Desorption–Extractive Electrospray–Mass Spectrometry

    Devenport, Neil A, Sealey, Laura C, Alruways, Faisal H, Weston, Daniel J, Reynolds, James C, Creaser, Colin S
    Analytical chemistry (Washington), 02 July 2013, Vol.85(13), pp.6224-6227 [Peer Reviewed Journal]
    ACS Publications (American Chemical Society)
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    Title: Direct Detection of a Sulfonate Ester Genotoxic Impurity by Atmospheric-Pressure Thermal Desorption–Extractive Electrospray–Mass Spectrometry
    Author: Devenport, Neil A; Sealey, Laura C; Alruways, Faisal H; Weston, Daniel J; Reynolds, James C; Creaser, Colin S
    Subject: Engineering ; Chemistry
    Description: A direct, ambient ionization method has been developed using atmospheric pressure thermal desorption–extractive electrospray–mass spectrometry (AP/TD-EESI-MS) for the detection of the genotoxic impurity (GTI) methyl p-toluenesulfonate (MTS) in a surrogate pharmaceutical matrix. A custom-made thermal desorption probe was used to the desorb and vaporize MTS from the solid state, by rapid heating to 200 °C then cooling to ambient temperature, with a cycle time of 6 min. The detection of MTS using EESI with a sodium acetate doped solvent to generate the [MTS+Na]+ adduct ion provided a significant sensitivity enhancement relative to the [M+H]+ ion generated using a 0.1% formic acid solvent modifier. The MTS detection limit is over an order of magnitude below the long-term daily threshold of toxicological concern (TTC) of 1.5 μg/g and the potential for quantitative analysis has been determined using starch as a surrogate active pharmaceutical ingredient (API).
    Is part of: Analytical chemistry (Washington), 02 July 2013, Vol.85(13), pp.6224-6227
    Identifier: 0003-2700 (ISSN); 1520-6882 (E-ISSN); 10.1021/ac401054n (DOI)

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    The quantitative surface analysis of an antioxidant additive in a lubricant oil matrix by desorption electrospray ionization mass spectrometry

    Da Costa, Caitlyn, Reynolds, James C., Whitmarsh, Samuel, Lynch, Tom, Creaser, Colin S.
    Loughborough University
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    Title: The quantitative surface analysis of an antioxidant additive in a lubricant oil matrix by desorption electrospray ionization mass spectrometry
    Author: Da Costa, Caitlyn; Reynolds, James C.; Whitmarsh, Samuel; Lynch, Tom; Creaser, Colin S.
    Date: 2013
    Subject: Mass Spectrometry -- Analysis ; Lubricants -- Analysis ; Antioxidants (Nutrients) -- Analysis;
    Description: Rationale Chemical additives are incorporated into commercial lubricant oils to modify the physical and chemical properties of the lubricant. The quantitative analysis of additives in oil-based lubricants deposited on a surface without extraction of the sample from the surface presents a challenge. The potential of desorption electrospray ionization mass spectrometry (DESI-MS) for the quantitative surface analysis of an oil additive in a complex oil lubricant matrix without sample extraction has been evaluated. Methods The quantitative surface analysis of the antioxidant additive octyl (4-hydroxy-3,5-di-tert-butylphenyl)propionate in an oil lubricant matrix was carried out by DESI-MS in the presence of 2-(pentyloxy)ethyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate as an internal standard. A quadrupole/time-of-flight mass spectrometer fitted with an in-house modified ion source enabling non-proximal DESI-MS was used for the analyses. RESULTS An eight-point calibration curve ranging from 1 to 80 μg/spot of octyl (4-hydroxy-3,5-di-tert-butylphenyl)propionate in an oil lubricant matrix and in the presence of the internal standard was used to determine the quantitative response of the DESI-MS method. The sensitivity and repeatability of the technique were assessed by conducting replicate analyses at each concentration. The limit of detection was determined to be 11 ng/mm additive on spot with relative standard deviations in the range 3-14%. CONCLUSIONS The application of DESI-MS to the direct, quantitative surface analysis of a commercial lubricant additive in a native oil lubricant matrix is demonstrated.
    Identifier: 10.1002/rcm.6690 (DOI)

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    Analysis of supramolecular complexes of 3-methylxanthine with field asymmetric waveform ion mobility spectrometry combined with mass spectrometry

    Arthur, Kayleigh L., Eiceman, G. A., Reynolds, James C., Creaser, Colin S.

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    Determination of free desmosine and isodesmosine as urinary biomarkers of lung disorder by ultra performance liquid chromatography-ion mobility-mass spectrometry

    Devenport, Neil A., Reynolds, James C., Parkash, Ved, Cook, Jason, Weston, Daniel J., Creaser, Colin S.
    Loughborough University
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    Title: Determination of free desmosine and isodesmosine as urinary biomarkers of lung disorder by ultra performance liquid chromatography-ion mobility-mass spectrometry
    Author: Devenport, Neil A.; Reynolds, James C.; Parkash, Ved; Cook, Jason; Weston, Daniel J.; Creaser, Colin S.
    Date: 2011
    Subject: Ion Mobility-Mass Spectrometry ; Urinary Analysis ; Copd ; Desmosine ; Isodesmosine
    Description: The elastin degradation products, desmosine (DES) and isodesmosine (IDES) are highly stable, cross-linking amino-acids that are unique to mature elastin. The excretion of DES/IDES in urine, in the free form and with associated peptide fragments, provides an indicator of lung damage in chronic obstructive pulmonary disease (COPD). A quantitative ion mobility-mass spectrometry (IM-MS) method has been developed for the analysis of free DES/IDES in urine with deuterated IDES as an internal standard. Resolution of DES/IDES isomers was achieved in less than five minutes using ultra performance liquid chromatography (UPLC) combined with ion pairing. The optimized UPLC-IM-MS method provided a linear dynamic range of 10-300 ng/mL and a limit of quantitation of 0.028 ng/mL for IDES and 0.03 ng/mL for DES (0.55 ng and 0.61 ng on column respectively). The method reproducibility (%RSD) was < 4% for DES and IDES. The UPLC-IM-MS method was applied to the analysis of urine samples obtained from healthy volunteers and COPD patients. The DES/IDES concentrations in healthy and COPD urine showed an increase in DES (79%) and IDES (74%) in the COPD samples, relative to healthy controls. The incorporation of an IM separation prior to m/z measurement by MS was shown to reduce non-target ion responses from the bio-fluid matrix.
    Identifier: 10.1016/j.jchromb.2011.10.016 (DOI)

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    The qualitative and quantitative analysis of lubricant oil additives by direct analysis in real time-mass spectrometry

    Da Costa, Caitlyn, Whitmarsh, Samuel, Lynch, Tom, Creaser, Colin S.
    Loughborough University
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    Title: The qualitative and quantitative analysis of lubricant oil additives by direct analysis in real time-mass spectrometry
    Author: Da Costa, Caitlyn; Whitmarsh, Samuel; Lynch, Tom; Creaser, Colin S.
    Date: 2016
    Subject: Direct Analysis in Real Time ; Mass Spectrometry ; Lubricant Additives ; Ambient Ionization
    Description: The application of direct analysis in real time combined with mass spectrometry (DART-MS) to the qualitative analysis of lubricant and oil additives, and the quantitative analysis of a lubricant antioxidant additive is reported. The additives were analysed alone and in the presence of a base oil, from filter paper, glass and steel surfaces, showing the potential of the DART-MS technique for the direct, rapid analysis of lubricant oil additives. The quantitative capabilities of the technique were evaluated for the antioxidant in an oil matrix at concentrations in the range 0.1-8mg/mL in oil (1-80??g antioxidant on spot), using a structural analogue of the antioxidant as an internal standard. The linearity (R2 =0.997), precision (% RSD=2.6%) and LOD (0.04mg/mL in oil) of the method demonstrates that DART-MS is capable of the rapid determination of additives in oil without pre-extraction.
    Identifier: 10.1016/j.ijms.2016.05.011 (DOI)

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    Untargeted metabolic profiling of saliva by liquid chromatography-mass spectrometry for the identification of potential diagnostic biomarkers of asthma

    Malkar, Aditya, Wilson, Emma, Harrison, Tim, Shaw, Dominick, Creaser, Colin S.
    Loughborough University
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    Title: Untargeted metabolic profiling of saliva by liquid chromatography-mass spectrometry for the identification of potential diagnostic biomarkers of asthma
    Author: Malkar, Aditya; Wilson, Emma; Harrison, Tim; Shaw, Dominick; Creaser, Colin S.
    Date: 2016
    Subject: Statistical-Process ; Clinical-Test ; Pilot-Project ; Data-Compression ; Biomarkers ; Proteins ; Acetonitrile ; LC:Liquid-Chromatography ; Metabolites ; Mass-Spectrometry ; Clinical-Diagnostics ; Statistische Analyse ; Klinischer Versuch ; Pilotprojekt ; Datenreduktion ; Biomarker ; Protein ; Acetonitril ; Flüssigkeitschromatographie ; Metabolit ; Massenspektrometrie ; Medizinische Diagnose ; Sciences (General);
    Description: Current clinical tests employed to diagnose asthma are inaccurate and limited by their invasive nature. New metabolite profiling technologies offer an opportunity to improve asthma diagnosis using non-invasive sampling. A rapid analytical method for metabolite profiling of saliva is reported using ultra-high performance liquid chromatography combined with high resolution time-of-flight mass spectrometry (UHPLC-MS). The only sample pre-treatment required was protein precipitation with acetonitrile. The method has been applied to a pilot study of saliva samples obtained by passive drool from well phenotyped patients with asthma and healthy controls. Stepwise data reduction and multivariate statistical analysis was performed on the complex dataset obtained from the UHPLC-MS analysis to identify potential metabolomic biomarkers of asthma in saliva. Ten discriminant features were identified that distinguished between moderate asthma and healthy control samples with an overall recognition ability of 80% during training of the model and 97% for model cross-validation. The reported method demonstrates the potential for a non-invasive approach to the clinical diagnosis of asthma using mass spectrometry-based metabolic profiling of saliva.
    Identifier: 10.1039/C6AY00938G (DOI)

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    Structural studies of metal ligand complexes by ion mobility-mass spectrometry

    Wright, Victoria, Castro-Gómez, Fernando, Jurneczko, Ewa, Reynolds, James, Poulton, Andrew, Christie, Steven, Barran, Perdita, Bo, Carles, Creaser, Colin
    International Journal for Ion Mobility Spectrometry, 2013, Vol.16(1), pp.61-67 [Peer Reviewed Journal]