A large amount of new designer drug diphenidine coexisting with a synthetic cannabinoid 5-fluoro-AB-PINACA found in a dubious herbal product

Abstract

Traffic police brought five dubious herbal product packages to our laboratory for toxicological analysis. These products usually contain one or multiple kinds of synthetic cannabinoids. In one of the packages, we identified the coexistence of a new type of dubious drug (diphenidine) with the synthetic cannabinoid 5-fluoro-AB-PINACA. Conclusive identification was performed by comparison of the mass spectra of the test herb extracts with those of the reference standards of diphenidine and 5-fluoro-AB-PINACA by both gas chromatography–mass spectrometry (GC–MS) and electrospray ionization–tandem mass spectrometry. Both mass spectra of the test extracts coincided with those of the reference standards for each MS method. Diphenidine and 5-fluoro-AB-PINACA were quantitated in the herbal product by GC–MS using selected ion monitoring and the standard addition method. The content of diphenidine in the herbal product was as high as 289 ± 23.2 mg/g (n = 5); that of 5-fluoro-AB-PINACA was 55.5 ± 5.8 mg/g (n = 3). Diphenidine is known as an N-methyl-d-aspartate receptor channel blocker. Although its human toxicity has not been studied, it is likely to have severe psychotropic action in humans. The very high content of diphenidine in the present herbal package should prompt law enforcement agencies to be aware of the potential harmful effects of diphenidine itself and also when consumed in combination with other drugs of abuse.