My Research, and Why Floyd Landis is an Ass

The Good: J.T. Brenna, master of the chemical universe, testifying at the Floyd Landis trial a couple weeks ago.

The Bad: Landis attorney Maurice Suh.

The Ugly: Floyd Landis, doped Tour de France winner and Lance wannabe.

And here by “my research” I mean my professor's research, and by “Floyd Landis” I mean his lawyer, who tried to argue against my professor. This isn’t strictly about Australia, but as my professor’s research is the real reason I’m here in Melbourne, I thought I might explain the principles behind gas chromatography and how they relate to the Floyd Landis Trial.

It’s always exciting when you find that your academic research has practical applications, so imagine the rush (yeah, I said rush) you get when you read about your research professor testifying at one of the biggest trials of the year. My professor back in Ithaca, Dr. Brenna, was in LA just a couple weeks ago, testifying twice as an expert witness for the United States Anti-Doping Agency (USADA) against last year’s Tour de France winner Floyd Landis. He specializes in some separation sciences, one of which is gas chromatography.

Chemists are control freaks who love manipulating substances. Separation science is the art of separating different chemicals. Sometimes you can use simple techniques to separate different materials—draining water from sand, for example, or letting the water evaporate, or boiling it. Separation becomes more difficult with chemicals of similar characteristics.

A GC with some attachments. This is what I've been spending my time with, instead of friends, for the past couple months.

Gas chromatography is able to separate very similar chemicals by sending them through a long, heated column that contains some stationary substance. Depending on that stationary substance, your chemicals will be attracted, repelled, or indifferent to it. If you were then to send a gas through the column and slowly raise the temperature to push the chemicals out, they would individually exit the column, depending on their attraction to the stationary substance. A “gas chromatograph” or “GC” is also equipped with a detector and timer that record the relative amount and time of these exiting chemicals via a series of peaks. Below is a sample GC readout, which shows a number of peaks, each corresponding to a different chemical. Those further to the right have exited the column later; those to the left exited the column sooner. Larger peaks indicate a larger amount of a chemical.

For a given column, stationary substance, and temperature program, you’ll find that each chemical takes a characteristic amount of time to travel through the column (“retention time”). You can put one chemical in the GC at a time, and determine its characteristic retention time. Later, when you have a sample of many unknown chemicals, you can put them in the GC and determine the chemical by its characteristic retention time.

Sounds pretty logical, right? Well, there’s a complication to this—sometimes completely different chemicals have identical retention times. Or sometimes their retention times overlap. In these cases, you haven’t separated your substances at all! You don’t know what chemical you’re looking at, or how much of the chemical your sample had. You won’t be able to convict Floyd Landis with this shoddy data!

That’s where two dimensional GC (“GCxGC”) can be useful. GCxGC uses TWO columns, one right after the other. The different columns contain different stationary substances, so they separate chemicals in different ways. If your chemicals have identical retention times with one column, they should be separated by the second column. Below is a sample readout from a GCxGC. Now, instead of looking straight at the peaks, we’re looking above them. The two axes correspond to the retention times on the two different columns.

Look at the peaks numbered 8 to 12. They would have been very close together, if not completely unseparated, on the first column. Fortunately for us the second column has separated them. Good thing, because now we have separated each chemical, and know how much of each we have.

Dr. Brenna wants to use a GCxGC to separate steroids. Last semester, he won a $1.3M grant from USADA to develop GCxGC steroid separation. My research professor in Melbourne, Dr. Marriott, is an expert on GCxGC, and is collaborating with Dr. Brenna on this steroid project. Their lab teams are currently looking at 27 steroids on the GCxGC and determining the correct column and temperature program to individually identify the steroids. They will create a library of characteristic retention times, and eventually be able to take urine samples, put them through the GCxGC, and determine both the identity and amount of these 27 steroids in a single sample of urine. Not only that, they’ll be able to do it much more precisely than anyone has done it before.

Think of how many times Lance Armstrong was accused of using steroids by a science lab, only to have the accusation retracted, based on insufficient evidence. Think of the current Landis trial. Hopefully Dr. Brenna will be able to provide the United States Anti-Doping Agency with a superior steroid testing protocol for the future.

What exactly were the separation scientists looking for in Floyd Landis’ samples? They were looking at his level of testosterone (a steroid). Everyone has some testosterone in their body naturally, and some have much more than others. The scientists look at the amount of testosterone relative to another steroid. They have found that this ratio has an upper limit naturally, and that this limit is only exceeded when one takes extra testosterone, which is precisely what happened in the case of Floyd Landis. Sorry, Floyd. You’re out. USADA says so, and J.T. Brenna agrees.

If you’re interested in a general article recapping the Landis trial, look here.

There are some articles that discuss Dr. Brenna, part in the trial, and his financial connection to USADA. Here and here.

If you’d like to read more about gas chromatography, you’re crazy. But here, here, and here you go.