Joe Caruso talks to May Copsey about warfare agents, proteomics and why elemental mass spectrometry is not just all about the metal.

Joe Caruso is a professor of analytical chemistry at the University of Cincinnati. Joe's research interests include metal profiling in clinical samples, developing methods for phosphorus-based functional group compounds from warfare agents to phosphoproteins and studies of Se phytoremediation. Formerly chairman of the Journal of Analytical Atomic Spectrometry editorial board, Joe is a member of the Chemical Society Reviews editorial board.

What inspired you to become a scientist?
I started out as a high school chemistry teacher but I realised that there was so much exciting chemistry out there and I wanted to teach it at a higher level. I became increasingly interested in the research. In particular, working with graduate students and postdocs is a great plus.

What influenced your decision to study analytical science?
I had a fantastic teacher at university who taught a course in qualitative analysis and he really inspired me. I also think analytical chemistry suits my personality. It is a very practical part of chemistry. For example, if you develop a new method to analyse for lead in somebody's blood, you see a clear application. It is this kind of outcome based research that drives me.

Can you tell me about the techniques that you use?
Our main-stay is elemental mass spectrometry, known as ICP-MS. It's mainly a metal-based technique, but it does an excellent job at looking at non-metal elements such as bromine, iodine, phosphorus and sulfur. It can be used to analyse for a variety of compounds, such as brominated fire-retardants, phosphorus-based warfare agents or phosphorylated proteins. It has a wide range of use, from small inorganic molecule analysis to proteomics.

What are you currently working on at the moment?

We are trying to obtain a better molecular level understanding of phytoremediation, the use of plants to remove pollutants from soil or water. We study selenium because it is present at high levels in agricultural fields of the Western USA. There's relatively little difference between the amounts that are toxic and the amounts that are required for life. We look at selenium as it undergoes changes within the plant. You can actually modify certain metabolic changes genetically, taking chemical pathways in different directions and ultimately enhancing the bioremediation qualities of the plant.

We've also been looking at chemical warfare agent hydrolyzates. We aren't certified for handling the actual agents themselves so we study these degradation products. These provide an interesting track to reveal if an agent was present or not. We started this project because our basis for their detection is to detect phosphorus as an internal tag by mass spectrometry, rather than looking at the molecule or functional group.

Some of our work focuses on clinical applications of analytical mass spectrometry. We combine elemental mass spectrometry and molecular mass spectrometry to allow metabolite detection at very low levels. We are collaborating with a neuroscientist, Dr. Joe Clarke, in the neurology department at Cincinnati. He's very interested in the metabolites associated with certain types of stroke. He believes there may be some metabolic markers involving non-metals, such as phosphorus and sulfur, that appear at very low levels in patients with post-stroke complications. If detected early enough, an appropriate intervention might be taken, either through drug therapy or some kind of physical intervention.

What is the next big thing that you would like to tackle in your lab?
Our movement into clinical applications is going to expand. There are particular sets of proteins in the shell, or capsid, of viruses. There's very little known about the metallo-protein aspect of various capsid proteins and this is something we'd like to take a look at. We are interested in seeing how the capsid reacts to either adding metals or removing them.

You obviously touch on a diverse range of chemistry areas. Is interdisciplinary research encouraged at Cincinnati?
Yes, interdisciplinary studies can be found in many areas at the University of Cincinnati. Our group has excellent collaborations. I started interdisciplinary work because I wanted to move into an area that seemed to be growing and with practical endpoints - atomic spectrometry. A lot of places now encourage collaboration because teams solve problems more effectively than individuals. More of the basic scientists are now collaborating and involving themselves with applied scientists. Especially in analytical science, techniques can be transferable to different kinds of problems or samples, such as environmental or clinical.

Do you have any advice for a young researcher keen to develop a successful scientific career?
The important thing is to keep your mind open. Scientists should not limit themselves or their thinking from reaching out into new areas. Collaborations will be even more the way of the future, but this also is consistent with establishing yourself as an independent scientist.

What do you like doing when you're not doing chemistry?
I enjoy boating and my grandchildren. I like to travel with family or friends. I often combine a few days holiday with my scientific travel commitments.