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Callan Littlejohn

welcome to my page, please find my contact details at the bottom of the page

PhD project

Evaluation of the capabilities of 2D Mass Spectrometry in a variety of molecular systems

External Partner

Verdel Instruments

Research focus

Working as part of the O'Connor Group, in the Millburn House ICR laboratory, my main focus is working on Two-Dimensional Mass Spectrometry, 2DMS is a truly data MS/MS independent technique that correlates fragment ions to their respective precursor m/z without the need for any isolation by passing ions through a fragmentation zone.

In order to gain a fuller comprehension of the processes involved in 2DMS i chose to focus on the fundamentals of Fourier Transform Mass Spectrometry. My initial studies focussed on confirming the Felgett effect in 2DMS, this work allowed for the development of an algorithm to confirm minimum sizes for acquisition of 2DMS. Recently my focus has been more centered around method development.


Google Scholar



In-Silico Demonstration of Two Dimensional Mass Spectrometry using Spatially Dependent Fragmentation, JASMS, 2023 doi:


BMSS Sept. 2021: gave a digital poster "Fellgett signal averaging in 2DMS"

ASCDT Sept 2021: gave a virtual presentation "Fellgett signal averaging in 2DMS"

TCT 3SIXTY sept 2021

Interplas sept 2021

LabInnovations Nov 2021

ASMS Jun 2022: poster "2DMS in a variety of systems"

ASCDT Jun 2022: poster "Short 2DMS of Covid-19"

EFTMS Jul 2022: Presentation "On the nature of Space charge: observations of dark charge effects"

IMSC Aug 2022: poster "2DMS in a variety of systems"

BMSS sept 2022: presentation: "2DMS in every mass analyser"

LabInnovations Nov 2022

Warwick Microbiology Cluster Meeting presentation "Two Dimensional Mass Spectrometry"

Warwick Chemistry Postgraduate symposium May 2023 presentation "Two Dimensional

Mass Spectrometry in every mass analyzer"

ASMS June 2023 Poster "Hyphenation of Trapped Ion Mobility with Two Dimensional Mass Spectrometry"

BMSS Sept 2023 Oral "Touchstone 2DMS: advanced Post-Processing for FTMS"

Grants and Prizes

John Beynon Travel grant: awarded by BMSS 2022

Nico Nibbering Student travel award awarded by IMSF 2022

Best Oral Presentation in stream B Warwick Postgraduate Symposium

John Beynon Travel grant awarded by BMSS 2023

Professional Memberships

Royal Society of Chemistry (AMRSC)

BMSS (Student Member)

ASMS (Student Member)

Get in touch!

a picture of callan littlejohn in front of his ASMS poster
ASMS 2022
 callan littlejohn presenting at EFTMS 2022
EFTMS 2022
Callan littlejohn imsc 2022
IMSC 2022
Callan Littlejohn presenting at BMSS 2022
BMSS 2022
Warwick microbiology cluster meeting 2022
Warwick PGR symposium
PGR symposium
ASMS 2023
ASMS 2023

Find me at Millburn House

Millburn House

Thank you