Synthetic Cathinones Stored in Biological Evidence Can Be Unstable

Synthetic cathinones, a class of mood-altering stimulants popular among recreational drug users, can be unstable when stored in blood or urine samples, and may be problematic when used as evidence in court.

February 12, 2018

Synthetic cathinones, similar to the psychoactive component in East Africa’s “khat” plant, are powerful psychostimulants originally sold on the streets under the name “bath salts.”[1] Although many synthetic cathinones were classified as Schedule I drugs — or drugs with no medical use and a high potential for abuse — in 2011 under the Federal Controlled Substances Act, new cathinones, designed with slight molecular alterations to avoid the Schedule I listing, are constantly being manufactured in drug factories, primarily in China.

In this NIJ-supported project, researchers at the Sam Houston State University College of Criminal Justice studied 22 synthetic cathinones to evaluate their stability in biological samples, such as urine and blood, in order to “interpret analytical findings in criminal and death investigations.” Their concern was that cathinones stored in blood and urine samples might degrade if stored in certain environments, making later measurements of drug levels in the samples unreliable.

“Cathinone stability was evaluated in preserved blood and urine at two concentrations and four storage temperatures,” the researchers said. “These were chosen to reflect frozen and refrigerated long- and short-term storage temperatures at the laboratory.” They also exposed the samples to room temperatures during processing and handling, as well as to elevated temperatures – about 90 degrees Fahrenheit - that might be experienced during shipping and transport.

Stability was also highly temperature dependent, pH dependent, and analyte (chemical structure) dependent, the researchers said, noting that the concentration of a cathinone in a sample did not make a difference. “Cathinones were most stable when frozen in acidic urine and least stable under alkaline [high pH] conditions at elevated temperatures,” they said. “Moreover, the chemical structure . . . had a profound influence on stability. Under some conditions, drugs were completely undetectable within twenty-four hours of storage.” The researchers ranked the stability of all 22 cathinones in their study, and while some were more unstable than others, for all of the drugs, “instability and the magnitude of the loss was heavily influenced by temperature, pH, and structural characteristics. Increased temperatures and pH were highly unfavorable and produced significant changes in [drug] concentration over time.”

The underlying lesson for investigators, they said, was that “concentrations at the time of testing may not always reflect those at the time of interest, for example the time of death or time of driving. Although drugs may still be detectable, significant losses are possible.”

Given that biological evidence is sometimes exposed to unfavorable conditions in both postmortem and antemortem toxicology investigations, they concluded, “toxicological findings related to synthetic cathinones should be interpreted cautiously and within the full context of evidence disposition.”

About This Article

The research described in this article was funded by NIJ award 2013-R2-CX-K006, awarded to Sam Houston State University College of Criminal Justice.

This article is based on the grantee report: Long-Term Stability of Synthetic Cathinones in Forensic Toxicology Samples (94 pages), by Sarah Kerrigan (principal investigator), Lindsay Glicksberg, Sam Houston State University College of Criminal Justice, Huntsville, Tx.

This research is part of a broader portfolio of forensic toxicology projects managed by NIJ Physical Scientist, Frances Scott, Ph.D. Find more information about NIJ-funded research on forensic toxicology.

Cite This Article

National Institute of Justice, “Long-Term Stability of Synthetic Cathinones in Forensic Toxicology Samples.”  February 12, 2018, NIJ.gov: https://www.nij.gov/topics/forensics/evidence/toxicology/pages/synthetic-cathinones-stored-in-biological-evidence-can-be-unstable.aspx

Date Created: February 12, 2018