About 4,500 separate tests will be performed at the Summer Olympic Games in Beijing to screen the participating athletes for banned substances. To keep pace with the seemingly ever-changing list of prohibited compounds--and keep a step ahead of savvy cheaters--test equipment maker Agilent Technologies Inc. must continually update the gas chromatograph, liquid chromatograph and mass spectrometer used for doping analysis.
Drug testing will be performed at the Olympics by the China Anti Doping Agency. CADA is certified by the World Anti Doping Agency, whose code specifies that drug testing may be performed on any contestant, anytime, anywhere, without notice. But some athletes will still look to beat the system.
"In recent years, the world of doping analysis has gotten much trickier," said Terry Sheehan, product manager at Agilent (Santa Clara, Calif.). "Athletes have moved beyond stimulants and painkillers, which are fairly easy to detect. Now, they're trying to engineer their bodies using compounds that mimic substances occurring naturally in the body. This cat-and-mouse game continually demands new analytical methods."
The first drug testing at the Olympics took place at the 1972 games and used Agilent instrumentation to test for performance-altering compounds, such as fatigue-reducing amphetamines. Since then, thousands of banned substances have been added to the list, including many, such as steroids, that may be used months before a competition.
Agilent works closely with independent testing labs to train personnel, enhance instrumentation and develop methodologies for detecting even those substances that mimic naturally occurring agents. For instance, the steroid nortestosterone differs from naturally occurring testosterone by only a single atomic bond.
Hundreds of compounds
On the list of banned substances are stimulants, narcotics, anabolic agents, steroids, diuretics, peptides and related compounds. In all, more than 400 substances and thousands of related compounds must be tested for each day. CADA estimates it will perform tests on 4,500 samples during the summer Olympics. In addition, the lab will be on lookout for new variations that could keep its technicians burning the midnight oil this August.
CADA will use the same Agilent models used by homeland security, forensics and criminal investigators; environmental monitors; and food-safety screeners. Over the years, Agilent has increased the sensitivity of its instruments to keep pace with the increasingly sophisticated methods drug users employ to evade detection. Today's test gear can detect traces of anabolic steroids even if the athlete stopped using them 10 months earlier.
Urine tests are the standard sample collection method for all of the screened compounds, but subsequent blood samples may be taken if a urine sample proves suspect.
Regardless of when or where a sample is gathered, its first stop after entering the testing lab is the Agilent 7890A gas chromatograph, which separates and detects the different components in the sample, isolating the banned substances from the normal biological molecules. The sample is vaporized with heat, and the gas enters the 7890A's separation column. As the gas moves through the column, the different atomic weights of its component compounds cause them to travel at different speeds (the lighter ones exit the column first). By measuring the speed, amount and sequence at which the components exit the column, investigators can readily identify most substances on the banned list.
But some compounds, such as peptide hormones, are destroyed by the vaporization process, requiring use of a liquid chromatograph. Using the same principle as the gas chromatograph to separate molecules by atomic weight, the Agilent 1200 series liquid chromatograph substitutes a liquid solvent that moves through the column. The liquid solvent takes longer to separate the molecules but preserves the molecules that would otherwise be destroyed by the heat of vaporization.
"About three out of four samples are analyzed using gas chromatography, but use of liquid chromatography is increasing because many of the new compounds are destroyed by vaporization," said Sheehan.
If either the gas- or liquid-chromatograph indicates a questionable substance is present, then the sample is submitted to the mass spectrometer, which can confirm the chemical identity of virtually any compound. The mass spectrometer measures the molecular weight of the questionable substance, producing a unique chemical fingerprint that is compared with the fingerprints of known banned substances, providing unambiguous confirmation of the gas- or liquid-chromatograph results.
To process the samples in real-time, the CADA lab will directly attach a mass spectrometer to each of its gas- and liquid-chromatographs, for a total of 19 gas/mass test stations and 18 liquid/mass test stations. p