Bryan J. McCullough
University of Edinburgh
Analytical chemistryMass spectrometryChemistryPeptideAntimicrobial peptides
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Publications 19
#1Sophie E. InmanH-Index: 1
#2Kate GrovesH-Index: 4
Last. Chris HopleyH-Index: 5
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Abstract The need for an analytical procedure for the identification of allergens present at trace levels in foods was highlighted by conflicting results in a case of contamination of the spice cumin. The application of a bottom-up proteomics experiment was investigated to identify marker peptides for potential contaminant nuts which could then be monitored with high specificity and sensitivity by selective reaction monitoring experiments. The method developed allowed for the distinction between...
2 CitationsSource
#2Sophie E. InmanH-Index: 1
Last. Chris HopleyH-Index: 5
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Abstract Recent developments in the miniaturisation of mass spectrometry have led to a new generation of low-cost instruments which are making MS a more accessible technology in all areas of analytical science. While the utility of these instruments for qualitative analysis has been demonstrated, their usefulness for quantitative analysis – particularly in complex matrices – has not been proven. Here we describe the development of a rapid LC-MS method for the analysis of drugs-of-abuse in oral f...
#1Tony Bristow (AstraZeneca)H-Index: 9
#2Andrew D. Ray (AstraZeneca)H-Index: 8
Last. Alessio ZammataroH-Index: 1
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For on-line monitoring of chemical reactions (batch or continuous flow), mass spectrometry (MS) can provide data to (1) determine the fate of starting materials and reagents, (2) confirm the presence of the desired product, (3) identify intermediates and impurities, (4) determine steady state conditions and point of completion, and (5) speed up process optimization. Recent developments in small footprint atmospheric pressure ionization portable mass spectrometers further enable this coupling, as...
21 CitationsSource
#1Ross ChawnerH-Index: 4
#2Bryan J. McCullough (LGC)H-Index: 11
Last. Claire E. EyersH-Index: 20
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Ion mobility-mass spectrometry (IM-MS) is a useful technique for determining information about analyte ion conformation in addition to mass/charge ratio. The physical principles that govern the mobility of an ion through a gas in the presence of a uniform electric field are well understood, enabling rotationally averaged collision cross sections (Ω) to be directly calculated from measured drift times under well-defined experimental conditions. However, such “first principle” calculations are not...
15 CitationsSource
2 CitationsSource
#1Hannah V. Florance (Edin.: University of Edinburgh)H-Index: 5
#2Andrew P. Stopford (Edin.: University of Edinburgh)H-Index: 3
Last. Perdita E. Barran (Edin.: University of Edinburgh)H-Index: 32
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Gas phase methodologies are increasingly used to study the structure of proteins and peptides. A challenge to the mass spectrometrist is to preserve the structure of the system of interest intact and unaltered from solution into the gas phase. Small peptides are very flexible and can present a number of conformations in solution. In this work we examine Melittin a 26 amino acid peptide that forms the active component of honey bee venom. Melittin is haemolytic and has been shown to form an α-heli...
24 CitationsSource
#2Tony Bristow (AstraZeneca)H-Index: 9
Last. Chris HopleyH-Index: 5
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The design and development of a novel extractive electrospray ionisation (EESI) device for on-line reaction monitoring is described. The EESI apparatus uses a secondary, grounded nebuliser to produce an analyte aerosol and a Venturi pump is then used to transfer a sample of the aerosol to an electrospray source where it is ionised. The EESI apparatus was then tested with a variety of small, organic molecules to assess sensitivity, linearity and dynamic range. The performance of the technique wil...
33 CitationsSource
#1Bryan J. McCulloughH-Index: 11
#2Peter A. FaullH-Index: 3
Last. Perdita E. BarranH-Index: 32
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#1Francesco L. Brancia (AU: Aarhus University)H-Index: 15
#2Bryan J. McCullough (University of Manchester)H-Index: 11
Last. Li DingH-Index: 1
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Traditionally, in a quadrupole mass filter, ion isolation is achieved by scanning the rf and DC voltages with a fixed ratio. In this paper, we describe an innovative procedure implemented in a digitally driven linear ion trap termed digital asymmetric waveform isolation (DAWI) in which ion isolation is obtained by manipulation of the duty cycle of the rectangular waveforms. Variation of the waveform duty cycle allows introduction of a precisely defined DC quadrupole component into the main trapp...
28 CitationsSource