Assessing Drug Residue on Smartphones Using Liquid Chromatography

Silhouette of hands using camera phone to take pictures and videos at live concert. © diy13- stock.adobe.com

A study done by scientists from the Grenoble Alpes University Hospital in France, examined smartphones as a new matrix for toxico-epidemiology. The study, which was published earlier this year in the journal of Clinical Chemistry and Laboratory Medicine, used ultrahigh-pressure liquid chromatography (UHPLC) and mass spectrometry (MS), on systems manufactured by Waters (1). Fingerprints on a phone’s surface contain perspiration and natural oils from skin that can reveal the presence of drugs, the scientists wrote. In addition, and the surface can retain traces of any drugs consumed directly from it.

An estimated 13.2 million people were injecting drugs in 2021, an 18% increase from 2020, according to a 2023 report from the United Nations (2). Yet, fewer than 20% of people with drug use disorders receive treatment, the report found. This makes it especially difficult for researchers to identify and study illegal drug use. Variability among drug use and various international drug laws make it challenging to gather accurate data on use (3).

The team of researchers, led by Théo Willeman, explored whether smartphones could be a better alternative for drug testing. The team invited attendees at several techno and trance music festivals in France to submit an anonymous questionnaire about their drug use, in addition to allowing the scientists to take a swab of their smartphones. The team collected 122 swabs, and using UHPLC, were able to identify several different drugs, including 3,4-methylenedioxymethamphetamine (MDMA), cocaine, tetrahydrocannabinol (THC), ketamine, lysergic acid diethylamide (LSD), methamphetamine, heroin, and mescaline. The results show that smartphones may be a non-invasive way to assess illicit drug use.

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“The opioid crisis in the US was recognized as a public health emergency by the US President in 2016,” Willeman said in a press release. “As a result, developing new tools to perform toxico-epidemiology studies is crucial, and identifying which substances are consumed in a particular area may help medical teams managing potential intoxications.”

UHPLC proved to be a reliable tool for detecting drugs on the surface of smartphones. The team found that swab analysis of smartphones could prove to be a useful and complementary tool for drug testing, showing acceptable performance even with declarative data, the scientists wrote (1). It successfully identified drugs of abuse, new psychoactive substances (NPS), and medications along with their metabolites. Advantages of this study include the use of a dry swab, quick sampling, and the accessibility of tandem-mass spectrometry (MS/MS). Despite some limitations, this method is promising for harm-reduction programs and toxico-epidemiology studies.

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However, the study was not without limitations. Because the researchers asked participants to self-report, the results relied somewhat on the reliability of the individual. In addition, the use of psychoactive substances often led participants to forget information or make errors, the researchers wrote (1). Additionally, the scientists said, further studies should be performed to better understand the stability of substances on smartphones over longer periods of time.

References

1. Willeman, T.; Grunwald, J.; Manceau, M.; Lapierre, F.; Krebs-Drouot, L.;et al. Smartphone swabs as an emerging tool for toxicology testing: A proof-of-concept study in a nightclub. Clin. Chem. Lab. Med. 2024, 0 (0). https://doi.org/10.1515/cclm-2024-0242
2. World Drug Report. (2023). https://www.unodc.org/res/WDR-2023/WDR23_Exsum_fin_SP.pdf (accessed 2024-06-19).
3. Ryan, J. E., Smeltzer, S. C., & Sharts‐Hopko, N. C. Challenges to studying illicit drug users. J. Nurs. Scholarsh., 2019, 51(4), 480–488. https://doi.org/10.1111/jnu.12486