- Analytical Chemist, Toxicologist & Biologist
- Not unusual for testing labs to be in a hurry.
- Cutting corners happens & mistakes are made.
- First lab found drug residue in a sample. The evidence was solid with confirmation.
- Horseman insisted his animal was clean.
- Specimen was sent to a second lab for confirmation found no drugs
- Third lab confirmation found to be devoid of any drugs.
After 15 years as a Analytical Chemist, Toxicologist & Biologist in various research and testing lab situations I can certainly say they are not all acutely dishonest. However, I can say it is not unusual for testing labs to be in a hurry. Consequently, cutting corners, either to meet deadlines or pinch pennies can, and does, happen. The upshot can be simple mistakes sometimes overlooking unique quirks of nature, the pit falls of assumption and bumbling through the usual array of human foibles. I have a few stories I can share as examples.
The corner cut that nearly put a lab out of business.
Like human athletes “performance” horses (example: race horses) must be drug-free when competing. Usually urine samples are taken post competition for all competing horses for laboratory testing. If a specimen is found to have drug residues in it, they are disqualified and possibly the horsemen or trainers will be penalized in some way for the violation. Usually the accused horsemen or trainer will simply admit guilt deal with the consequences. But sometimes they really do have reasons to challenge the lab results. Typically, the putative sample is sent to a second lab for confirmation and the drug is usually confirmed so there isn’t much advantage in fighting it.
However, sometimes mistakes are made. As an example, one time a member laboratory did find drug residue in a horse sample. The evidence was quite solid with both chromatographic and mass spectrum confirmation. Usually such results are not worth challenging but the horseman insisted his animal was clean. So the specimen was sent to a second lab for confirmation and to our amazement they found no drug in it! A third lab confirmation was run and once again the sample was found to be devoid of any drugs. So what happened in the first lab?
They were using a GC-MS which means the sample was injected into an instrument called a gas chromatograph or “GC” where trace residues of the drug are separated from other trash as it passes through very thin tube we call a “column.” The time it takes a drug to pass through this column is somewhat unique to the drug, thus giving a tentative identification based on what we call “retention time.” As the drug passes out of the column, it then enters a mass spectrometer, or “MS,” which gives a nearly absolute identification of the drug. Most of the time when a defendant sees a mass spectrum such as this, they know the game is over. But something happened here that was different. Clearly, as far as the horseman was concerned, the game was not over!
Because our lab was the organizing a QA/QC hub, the sample and all sample data, from the first lab, were sent to us to examine. The sample was indeed clean. But the record log of sample injections from the first lab revealed a problem. A “standard” of the very same drug they reported as being in the sample was injected on their GC/MS prior to the actual sample.
Standards must be injected on an instrument to prove you can actually see the chemical if it were present in a sample. However, sometimes very small residues of the chemical may “hang-up” in the system. There is a variety of reasons this can happen but when it does, the next injection of even clean solvent can dislodge some of the hung-up residue causing it to appear to be in the sample when, in fact, it is not.
The solution to this problem is running a “blank” which is simply a shot of pure solvent or an extract from a known clean source. If the drug happens to appear, then there is a problem and your instrument will require maintenance. The blank also shows you cannot trust the results from any subsequent sample injections on the instrument. The first lab did not run a blank between the standard injection and the actual sample. If they had, there would have been no problem and all the fuss would not have had to happen. They would immediately know it was a false-positive test. The lab may have simply overlooked this simple protocol or they didn’t want to take any more delay time for a high priority specimen. Either way, the lab was in trouble. Indeed they were ejected from the quality circle of labs running performance horse samples thus losing a significant load of business. The horseman, on the other hand, was wise to challenge the test results and came out with his integrity and respect intact.
All animals have to eat!
Violations are sometimes embarrassingly innocent. Like human athletes, athlete horses are required to be completely drug free when competing. After each race a urine sample is take and shipped to a testing lab to make sure everyone is onboard with this requirement. But sometimes strange things happen. Such was the time when all of the horses managed by one horseman were found to be fortified with caffeine. This was definitely not a lab error. Literally all of his horses were ineligible because of caffeine. The horseman was more than just a little alarmed, he was livid. He insisted there was no way he would spike his horses with any such drug. We briefly examined the possibility of sabotage, which does happen, but the cause was much more simple than that. The horseman had been feeding his horses with a type of feed which was amended with the very nutritious grindings of cocoa shells. After all, the horse farm was in the neighborhood of Hershey’s chocolate factory and animal feed is a way they creatively dispose of the otherwise waste product from processing the cocoa nut they use for chocolate. It is also replete with caffeine. This would be no problem for the common horse owner, but in performance horses, it is a problem. No one, including or lab could have suspected it.
Assumptions on how drugs enter the body
I have heard some “experts” claim skin is one of the most impervious barriers you find in human or animal anatomy. This is, of course, not true at all. But most often when horsemen think they are risking a drug violation, they think of drugs applied orally or by injection. Such confusion once appeared in our lab when a performance horse was found to have high levels of benzocaine in its urine. The horseman insisted he never administered benzocaine to any horses. That would be silly. Benzocaine?! Benzocaine is usually administered as a liniment, applied to sore or swollen joints. So, naturally, the horseman was asked if such a liniment was applied to the horse in question and, indeed, it had. Could the externally applied benzocaine end up in the blood and consequently in the urine? Our lab had test horses to be used for this sort of question. The liniment was applied to the lower leg of a horse and over time, urine samples were drawn. The samples were extracted and tested for benzocaine. Indeed huge amounts of benzocaine had traversed all the anatomical barriers from the skin of the leg to the urine. So we were once again all educated to the dynamics of drugs in the equine body. Although the drug had been naively applied to the horse’s leg, thinking it would not show up in its urine, any drug applied to help the animal perform in sport competition is usually considered illegal. The laws and regulations are always subject to change but, at least at that time, a horse in need of such therapy should not have been competing at all.
When field collectors get impatient
A drug was found in a performance horse’s urine sample and the horseman insisted his horse was clean. All confirming analysis protocol were conducted and it was perfectly clear the sample did have the drug in it. But simply finding drug residues does not always end the story. Most folks who are not familiar with drugs in humans or animals are not aware that the actual drug molecule (“parent compound”) seldom ends up in urine unchanged. The drugs are “metabolized” into many different types of molecules or molecular fragments and these are called “metabolites.” There could be dozens of them. Here the critical issue was this: the types of metabolites differ from one species to another. Fortunately, we could isolate and identify some of the specific metabolites from the putative sample. Turns out the metabolites in the urine sample were not from a horse at all. They were human!
How did this happen? Some simple sleuthing was required. We sent someone to the track to strike up a conversation with the sampling technician and casually asked if he happened to be taking any prescription medication. It was a little startling when he casually responded, “yes” he does take the exact prescription medication found in the horse sample! That was the answer to our problem! You see, most performance horses will easily and promptly offer a urine sample after a competition such as a race. But once in a while, a horse will simply be dry or not interested in peeing. Normally the sampler simply has to wait, but on that day the sampler was in a hurry. Maybe he had a date to keep? But with his impatience, he finally resorted to peeing into the sample cup himself, never thinking the drug he was taking might show up in the lab. Presumably he thought since we were testing for drugs in horses we would never find something in a human sample. It is hard to say.
The upshot for this story is that a very well confirmed positive test can come from a sample with a convoluted history which completely changes its meaning. In this sort of work one always has to be ready to look outside the box.
About the Author:
Provides Opinion & Testimony In:
Analytical Chemistry, Toxicology & Biology, Chemicals, Biology Entomology, Bioanalytical, Environment, Pharmaceutical, Metabolism, Metabolites, Degradation, Biochemistry, Pesticides, Insecticides, Herbicides, Fungicides, EPA Certification, Bioactive Compound Analysis, Golf Course Contamination, Biology Corporate Country Club Contamination, Dioxins, Toxicology Hazardous Waste, Airborne Aldehyde Ketone Contaminations, Formaldehyde, Acetaldehyde, Acetone, Chemical Characterization, Identification Of Trace Contaminants, EPA Analytical Methods, FIFRA Guidelines Of Pesticide Registration, Good Laboratory Practices GLP, Data Techniques, PCB Analysis, SW 846 Analytical Methods, Toxicity Assessment Humans, Underground Storage Tank Soil Analysis, Acquisition Assessment & UST Leak Data.