New Drug Testing Method Can Reduce Risk of Accidental Exposure
Written by Rich Press   

FOR POLICE, FIRST RESPONDERS, and forensic chemists, testing a suspicious powder can present a risk of accidental exposure via inhalation. This can be especially hazardous if the powder contains fentanyl. Now, scientists at the National Institute of Standards and Technology (NIST) and state forensic laboratories in Maryland and Vermont have demonstrated that a reliable preliminary identification of the contents of a suspicious package can be obtained without opening it, reducing the risk of accidental exposure.

 


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The proposed method involves swiping the outside of a baggie and then analyzing the swipe using Direct Analysis in Real Time Mass Spectrometry (DART-MS). This approach can reliably predict whether a package contains fentanyl, even if mixed with cocaine, heroin or other substances. The method was described recently in Forensic Science International.

“What’s needed is a fast and safe way to screen drug evidence so that it can be handled appropriately,” said Ed Sisco, a research chemist at NIST and the lead author of the study. After screening, hazardous packages can be flagged so they are opened only under a laboratory fume hood.

Traditional colorimetric tests require that the tester open a package and scoop out a bit of powder for testing. Many police departments now discourage or prohibit these tests in the field for safety reasons. Instead, officers must send the suspected drugs to a crime lab, then wait for a result before getting a search warrant or making an arrest.

Amber Burns, manager of the Maryland State Police forensic chemistry lab and a co-author of the study, said that she gets a lot of rush requests, and each request currently requires a full work-up of the evidence. Her lab plans to install a DART-MS instrument to do the quick screening, which should speed up the process considerably. “They just need to bring me the swipe, and they can be on their way in two minutes,” she said.

 

A baggie containing an unknown powdery substance is swiped for screening. Image courtesy NIST.

Ion Mobility Spectrometry (IMS) instruments, which are small enough to fit in a police vehicle, could provide a viable approach for field testing. Wherever the screening is done, it provides only a preliminary identification. To bring a criminal case to court, a complete work-up using standard laboratory equipment would still be necessary.

To conduct this study, the NIST scientists teamed up with Burns and her counterpart at the Vermont Forensic Laboratory, Rebecca Mead, who was also an author of the study. When suspected drug evidence arrived at their labs, Burns and Mead swiped the outside of the packages. Most were plastic baggies, though they also included envelopes, tinfoil, and pill bottles. The chemists also dissolved a small amount of the suspicious material in alcohol and put a drop of the resulting solution onto a second swipe for comparison. They then sent the pair of swipes to NIST for analysis.

The NIST authors received swipes from 191 suspicious packages, which they analyzed using DART-MS and liquid chromatography-mass spectrometry (LC-MS/MS). Those swipes contained an array of illicit drugs, including several fentanyl analogs, heroin, cocaine, methamphetamines, and ketamine. Many of the cocaine and heroin samples included smaller amounts of fentanyl. The swiped packages also contained plant material sprayed with synthetic cannabinoids, which are often marketed as K2 or Spice.

Two of the packages contained carfentanil, which can be particularly dangerous if accidentally inhaled. Carfentanil is roughly 5,000 times as potent as heroin.

The authors found that swiping the outside of a package correctly predicted its contents 92% of the time. For samples containing fentanyl and other opioids, the outside of the package predicted the contents in all cases. Therefore, if the goal is to flag fentanyl-containing packages for special handling, the technique appears to be effective.

The 8% of non-matches involved cases where several bags of different material were placed together by police into a single evidence bag, allowing for cross-contamination. Also, the technique did not work in most cases involving plant material in heat-sealed bags.

This study builds on previous research by NIST scientists proving the concept of testing with an external swipe. This new study is the first to quantify the effectiveness of the method. It is also novel in that it used real casework samples, making this the first field test of the method.

This swipe technique will do more than help police get faster answers when investigating drug crimes. It will also help at crime labs. At the Maryland lab, Burns said that upon receiving evidence they use color tests—the same tests that officers once used in the field—to quickly get an idea of what’s in the bag so they can line up the right types of laboratory analysis. But those color tests don’t detect many of the new designer drugs that make up an increasing fraction of the caseload.

The swipe test will work for this, however. “We plan to use this to optimize our whole workflow,” Burns said.

About the Author

Rich Press is science writer and public affairs specialist with the National Institute of Standards and Technology.

This article appeared in the Winter 2019 issue of Evidence Technology Magazine.
Click here to read the full issue.

 
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