20 October 2008
Spiros Pergantis talks to May Copsey about metals in biology and the environment, the future of metallomics and how he nearly became a pilot
 | Spiros Pergantis is an associate professor in analytical chemistry at the University of Crete and a member of the Journal of Analytical Atomic Spectrometry advisory editorial board. His research involves the development and application of analytical methods for the detection and characterisation of metal-containing species in a variety of biological and environmental samples. |
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Why did you decide to become a chemist?
I come from a generation in Greece where many of our parents, because of the war, were not well educated. So it was important for them that we got a good education, and natural sciences were easy for me. I like experimental subjects. In high school, I wanted to figure out what chemistry was about so it became my first choice. For the first six months in university, I didn't like it very much because the practical labs weren't very inspiring. I almost took another option - to become an air force pilot. To become a pilot in Greece, you have to go into a military national academy. I had the marks but they needed an approval form. Luckily, my parents refused to sign it. I had to become more patient with chemistry and in my second year, I really started to appreciate it.
When did you decide to specialise in analytical chemistry?
I went to the University of British Columbia in Vancouver and did my PhD with Professor William Cullen. That was a great experience. Bill Cullen is a synthetic inorganic chemist who had gone into analytical chemistry to study speciation in real samples, so I'm a bit of a mix. For some of the methods that we used, we had to isolate and purify milligram amounts of compounds from natural sources to get good NMR spectra. At that time, I thought: 'I'm never going to do this; it's too tedious.' So I started to get more involved with mass spectrometry to figure out how to perform these tasks with less purification and without requiring huge amounts.
"Even if you have a very good knowledge of chemistry, current science requires that you are able to expand it into other areas and biology is one of these areas. We need people to understand both chemistry and biology and what's happening at that interface"
Then I went to the US Environmental Protection Agency to do a post doctoral fellowship. The idea there was to come up with micro-chromatographic methods suitable to couple with two types of detectors, so we could get both element speciation information and molecular information from an ICP-MS (inductively coupled plasma mass spectrometer) and from an electrospray MS. That was new back then, but even now we seem to struggle to get this concept working efficiently.
Is chemistry popular with students in Greece?
Yes it is. However, biology is also becoming an even more popular choice so I think that we have to look into updating and creating joint programmes between chemistry and biology, like a lot of universities in the UK have done. Even if you have a very good knowledge of chemistry, current science requires that you are able to expand it into other areas and biology is one of these areas. We need people to understand both chemistry and biology and what's happening at that interface.
What's the most exciting research in your lab at the moment?
Apart from continuously trying to characterise novel arsenic, selenium and antimony species, we are now developing a novel hyphenated technique that involves coupling a nanoelectrospray ion mobility spectrometer with an ICP-MS. The idea behind this is that nanoparticles can be separated by size, ranging from three to 150 nanometres, using the ion mobility spectrometer. The element composition can then be determined in the ICP-MS. We do this because the sizes of biomolecules, such as proteins and DNA, are within this range. We can now use this novel hyphenated technique to size biomolecules; however, we still need to improve the system's overall sensitivity in order to be able to determine the metal or heteroatom content of the biomolecules.
We can also use this system to investigate how metal species interact with biomolecules. Nanoelectrospray is ideal for this as it does not tend to disrupt weak interactions, even non-covalent interactions. In this way we can probe the function of metal species. Our community has identified over 50 different compounds for arsenic and we are also finding many metabolites for antimony. However, we don't know what their functions are.
Another interesting application would be to use electrospray to introduce viral particles into the gas phase. They contain metals in their proteins and we could possibly get fingerprints for these.
Then there is materials science, where nanoparticles are produced. To a limited extent, they are already being introduced into the environment, and in the future, this will increase. There'll be a need for techniques to characterise these, at a screening and an analytical level. Right now, we don't understand the behaviour of these materials in the environment or in biological systems very well at all.
This nanoelectrospray ion mobility ICP-MS is a technique I'm really interested in and we will see how far it takes off.
How do you come up with the idea of what you are going to investigate next?
The main inspiration is the many questions that arise on a daily basis from the research conducted within my group. However, you also attend a lot of meetings and seminars to get ideas. To help with all this the University of Crete is extremely active in research. We have top-notch scientists visiting and giving lectures so it is a very good environment in which to seek collaborations. There a lot of highly motivated scientists, so even within the university we can find collaborations. Occasionally, we get problems that are a little bit more applied like chromium in drinking water. That's an issue in Greece. There are some industrial areas where the levels of chromium VI have gone up. I haven't been involved with that so far but I think in the future, we will be. I think at this point in my career, I can do some of the things that are not 100 per cent academic, but I am able to give back directly to the community.
Do you have any collaborations with other researchers?
We collaborate with some medical groups on the metabolism of metal-containing drugs. We offer analytical tools to characterise the metabolites that are being produced and provide a better understanding of the mechanism of how the drug works. We also collaborate with biologists, environmental scientists and even materials chemists in some cases.
In our group, we try to identify new compounds that are present in biological or environmental samples. We really don't know what they do or why they are formed, but this is knowledge that a synthetic chemist can use to make these new compounds, and a toxicologist can then test them. Our data may also be used to see if there is something that relates to these compounds in terms of public health. Identification, or speciation analysis as we call it, is the key first step.
We really need to expand on this a lot more so we need more interdisciplinary conferences. We can't just have conferences where analytical chemists talk about the techniques; we really need public health people, toxicologists and others involved.
How do you see the field of metallomics developing?
"I think metallomics will be a complementary area, maybe not as big, but an essential part of the puzzle, so we have to be ready"
I think that we have a lot to learn by looking into the areas of metabolomics and proteomics. I think metallomics will be a complementary area, maybe not as big, but an essential part of the puzzle, so we have to be ready. We have to follow the huge developments that are being made in these areas and adapt them to metallomics. There's no reason that what can be done with organic compounds cannot be done with most inorganic, organometallic or metal-containing biomolecules. There are many different communities and there are not enough bridges between them. The groups that have used both molecular mass spectrometry and atomic techniques have really made some amazing advances, which could never be made if you just stuck to the traditional atomic techniques. I think we are really making good progress as a result of this synergistic effect.
Finally, if you weren't an analytical chemist, what would you like to be?
When I was at high school I wanted to be a football player. However when I was 16 my dad said, 'It's not going to happen for you. Do it as a hobby, but do something else as a profession.' As always, it was probably good advice.
The RSC is launching the new journal Metallomics
in January 2009. For more information and free online access visit www.rsc.org/metallomics.
Related Links
Read more about Pergantis' work here
Pergantis' page at the University of Crete
Chemistry World.
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