GEN-MKT-18-7897-A
Aug 20, 2024 | Blogs, Forensic, Toxicology | 0 comments
Read time: 3 minutes
You probably have heard of testing blood and urine samples for the presence of drugs and their metabolites. But do you know about the benefits of hair and nail analysis? In a recent webinar, Tina Binz, Deputy Head of the Center for Forensic Hair Analysis, University of Zurich, discussed the benefits of developing comprehensive and sensitive LC-MS/MS for the detection of low-level drugs and metabolites in keratinized matrices. Below are some of the most intriguing questions that were asked by the audience during the Q&A session of the webinar.
Sometimes, a single intake like one pill, one milligram or one microgram is enough to be detected. It really depends on the substance that is ingested. For example, for alcohol, you must take a little bit more so we can see it, but for fentanyl or other compounds, you can typically detect them after a very low dose intake.
After ingested, the drug enters the bloodstream, and it typically takes at least 4 weeks to be incorporated into the keratin matrix and be detectable. There may be some direct contamination from sweat, but in general it takes at least 4 weeks for the substance-incorporated hair to grow out and for the drug to be detectable in it.
Yes, it does matter. You can collect samples from body sites other than the head, but we normally take samples from the back of the head. Studies have shown that substances are distributed in different concentrations across the head due to sweat and sleeping patterns. It is also recommended that the two samples be taken very close to each other.
The results are as robust as head hair, but the difference is that not all body hair is suitable for forensic application. For example, pubic or auxiliary hair can be heavily contaminated by sweat or urine, so you can get false positives or higher-than-expected results. That’s why they are only used in emergency situations, and it is better to take leg hair, arm hair or chest hair, for example.
Hair usually grows at a rate of about 1 cm per month, so it depends on length. Nail clippings present the last two to three months. However, newborns have exceptionally long nails that we believe show the last five to six months in the uterus.
We compared children to adults and found that the results for mothers and babies correlate. Also, the findings in hair and nails correlate.
Yeah, it depends. Diet and lifestyle don’t affect drugs like cocaine, but they can affect stress levels. For examples, when monitoring stress markers in athletes, we observed that their values can be higher or lower than expected due to their lifestyle. Age also tends to affect cortisol levels, a commonly measured stress marker.
Due to their complexity, there is no reference data. For stress markers, values are only high or low. We conducted a meta-study investigating a huge cohort of volunteers and determined so-called baseline values for cortisol, which were between 1 and 5 pg/mg. From this, we postulated that cortisol levels above 25 pg/mg were considered high. These hypotheses were supported by patients with clinical conditions like Cushing syndrome, who have naturally elevated cortisol levels.
For drug-facilitated crimes, it is best to have a blood sample directly after the event took place so they can see what happened a couple of hours before. However, many victims do not go straight away and give a blood or urine sample. They come weeks and weeks later when the substances can no longer be detected in the blood or urine. So, in this event, we can analyze hair samples for all kinds of drugs like GHB, benzodiazepine, alcohol and many more.
I showed that for fentanyl, we had at least ten times more sensitivity. For steroids, we had up to twenty times more sensitivity and sometimes even more. We also got comparable results for THC and amphetamines, but sensitivity improvements are also analyte dependent.
Want to learn more?
Dive deeper into the fascinating world of hair and nail analysis by exploring our on-demand webinar. Whether you are a forensic scientist or a researcher curious about drug analysis in keratinized matrices, this webinar offers essential knowledge to enhance your expertise and provides valuable insights on the benefits of LC-MS/MS for comprehensive drug analysis. Don’t miss this chance to learn from a leading expert.
Watch now >
And check out this technical note published in collaboration with Dr. Tina Binz to learn more about how they are leveraging LC-MS/MS for the long-term retrospective measurement of stress markers in keratinized matrix.
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