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Biography

Stephen is an Organic Geochemist who researches chemcial fossils and sedimentary organic matter and develops novel analytical technologies for chemical analysis. He has worked on international expeditions as a lead sedimentologist and geochemist. He manages a laboratory that conducts consultancy and research. His students start and run businesses and play leading roles in industry, education and their communities.

Research Overview

Important Projects and Publications

A range of my research is below. Something recent, something old, something commercial and something applied. Maybe something for anyone; if resources permit (normaly time is limiting factor) I am always willing to collaborate. You can also check out my - I particularly like catching up with old students and hearing from like-minded strangers (the stranger the better)!

Most recent paper (2024): The perturbation of PAHs on mosses in Aberdeen, Scotland, as a consequence of social restrictions imposed during the COVID-19 pandemic. doi.org/10.3389/fgeoc.2023.1320096

My most recent paper is about the measurement of PAH on mosses during the COVID-19 lockdown. Aberdeen does not have its own Environmental PAH monitoring station so instead mosses were used as sampling devices. The changes in pollutant PAH matched changes in traffic as Scotland went in and out of different levels of restriction.

Figure above shows the increases in MMW PAH on mosses in Aberdeen after the Covid-19 restrictions were lifted.

Most cited paper (2005): Biomarker evidence for green and purple sulphur bacteria in a stratified Palaeoproterozoic sea. doi.org/10.1038/nature04068

My most cited paper is about the earliest fossil occurrence (chemical fossil) of a green sulphur bacteria, publsihed at a time when chemical fossils in precambrian rocks were more uncertain than they are now. It involved careful chemical analysis by GC-MS.

Figure above shows the 134 m/z ion chromatogram - the little i is the peak for isorenieratane, evidence for green sulpuhr bacteria.

Most impactful paper (2009): Determination of the asphaltene and carboxylic acid content of a heavy oil using a microfluidic device. doi.org/10.1039/b814495h

This is my most important paper from an economic perspective as its ideas were used to start a (RAB microfluidics) that attracted > £2 million in start-up funds. The paper is about the design, testing and building of a microfluidic chip and a method to analyse heavy oil. Later the method was used to commercialise a sensor for lubricating oil analysis.

From blue sky idea to product - took a very hard working PhD student (Dr Alabi, 10+ years and input from many others)

Consultancy Work (2023): Detection of nano-particles in oils during waterflood experiments

A local SME asked me to develop a method and use it to detect nano-particles in oil at sub 1% concentrations. The method was applied to both core flood experiments and real time adsorption experiments.