Rachel L Gomes
Lecturer in Chemical and Environmental Engineering, Faculty of Engineering
Current Research
Working between the disciplines of engineering and chemistry allows research into chemicals that are biologically active. These chemicals exert a biological effect on an organism which can be desirable as in the case of steroids which are responsible for sexual characteristics and reproduction, or pharmaceutical drugs for treating health problems. However these chemicals are undesirable when used inappropriately or inadvertently come into contact with organisms causing adverse effects. Current research projects cover steroid and pharmaceutical fate and mitigation in wastewater treatment and the aqueous environment, purification of artemisinin for use in anti-malarial treatment, and source identification of steroids for detecting drug cheats in forensic analysis and PAHs.
Environmental engineering: steroids in wastewater treatment Steroids are naturally excreted from our bodies and enter the wastewater treatment process. However the inefficiency of wastewater treatment has resulted in steroids being present in the wastewater effluent and being released into receiving water courses. This has led to global concern about the adverse effects and risks to aquatic wildlife and human health respectively. Reduction at source is not possible hence water treatment has to remediate these steroids and other biological active chemicals by developing and modifying the unit treatment operations and processes thus preventing entrance into receiving waters or drinking water supplies. Traditionally the focus has been on free steroids, however research has shown that accounting for the conjugated steroids which are the precursors to the free steroids are extremely important in understanding their fate and removing these chemicals from environmental matrices. A review of the current treatment approaches and conditions is ongoing with research into optimising secondary treatment operations and the viability of advanced oxidation processes for tertiary treatment.
Chemical engineering: processing artemisinin for anti-malarial drug treatment Processing of the raw leaf material Artemisia annua produces the biologically active chemical, artemisinin which is used in anti-malarial drug treatment. Heavy rainfall in 2010 has led to reduced leaf availability and increased cases of malaria. This has necessitated research into improving the extraction and purification processes to produce a greater yield whilst retaining high purity. Current research is investigating benchscale novel extraction approaches and optimising standard approaches for the procesing of artemisinin from raw leaf with scale up in 2011 at an African processing facility.
Forensic analysis: prospecting for steroid drug cheats Forensically, there is a need to identify biologically active chemicals in humans and food stuffs due to public health concerns and/or legal requirements. The desire to win can leave sportsmanship in the starting block, with some athletes resorting to taking anabolic steroids in an attempt to gain that competitive edge. Detecting steroid drug cheats remains a high priority in international sports yet analysis can be challenging. Gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) offers the ability to discern whether the origin of the steroid is natural or from doping. However, the current preparative steps suffer from problems hampering testing procedures. Understanding and alleviating these preparative problems is an area of ongoing research and a suitable preparative alternative would be advantageous. Hydropyrolysis (hypy) is a geochemical technique engineered and commercialised within the University of Nottingham and most commonly used in prospecting for oil. Recent application of hypy has led to a preparative approach able to overcome the current preparative problems thereby allowing for GC-C-IRMS analysis of important urinary steroids for detecting steroid drug cheats.
Forensic analysis: PAHs and source determination The application of hypy to other biologically active chemicals such as polycyclic aromatic hydrocarbons (PAHs) is currently being investigated. PAHs are one of the largest and most ubiquitous groups of environmental pollutants entering humans through smoking or diet. Identifying the source of exposure within the human body can inform on risk and mitigation. However the same issues experienced for steroids in sports testing are experienced with preparing PAHs for GC-C-IRMS to discern origin.
Science enrichment and communication Dr Gomes' interests also extend to science enrichment and communication. She is a STEMNET Ambassador who has devised and delivered science workshops and given talks to both Primary and Secondary Schools covering a range of science disciplines. Dr Gomes has also participated in larger science outreach activities, including the UK Big Bang Science Fair (London 2009) and the BBC Bang Goes the Theory Roadshow (Nottingham 2010). Dr Gomes is also involved with Next Generation Project which she participates in and co-manages. The motivation behind the NGP is to inspire an excitement in primary school pupils for science and engineering, and form a teacher-scientist partnership which provides a high quality programme of science workshops intended to develop teachers' scientific understanding and the scientists' ability to disseminate scientific concepts to the general public. The NGP also devises training workshops for scientists and teachers towards these aims.