Study of the fragmentation pattern of ketamine-heptafluorobutyramide by gas chromatography/electron ionization mass spectrometry

Microextraction by Packed Sorbent as a Clean-up Approach for the Determination of Ketamine and Norketamine in Hair by Gas Chromatography--Tandem Mass Spectrometry

The use of new psychoactive substances has been increasing and constitutes a social and public health problem, and hence, toxicological analysis has become of utmost importance for the detection of such substances. In this article, we present the development and full validation of a simple, user and environmentally friendly, cheap and suitable method for the determination of ketamine and its main metabolite norketamine in hair samples. The procedure included using a miniaturized procedure-microextraction by packed sorbent with mixed-mode sorbent-for sample clean-up. Organic solvents use was minimal, and it was possible to obtain a linear method (0.05-10 ng/mg for both analytes). The extraction efficiency ranged from 32 to 61%, which did not impair sensitivity. The method proved to be selective, precise, accurate and suitable for routine analysis for the determination of said compounds in 50-mg hair samples.

A validated GC-MS method for ketamine and norketamine in hair and its use in authentic cases

This work has shown that it is a valid method for determining ketamine, norketamine and amphetamines derivates in hair samples of forensic cases. This method was validated meeting the criteria of sensitivity and accuracy for detecting repeated consumption of ketamine in hair samples of forensic interest, according to the proposed cut-off for ketamine of 0.5 ng/mg. The detection of norketamine allowed discriminating between active uses and external contamination. The assessed method was applied for analyzing 1189 hair samples of judicial interest received in the INTCF along 15 months, obtaining 62 positive in ketamine consumption. This means a 5.2% of positivity. Ketamine consumers present a profile of young age (21-30 years old), polydrug use with consumption of synthetic substances preferably MDMA and, then, amphetamine. As consumer is collective, prone to consume new psychoactive substances, requires special attention due to they show a consumer profile with higher prevalence in MDMA than amphetamine, indicating that ketamine consumers belong to a subgroup with a different profile within the INTCF casuistry. The results of the exercises of the proficiency tests performed satisfactorily in all cases. In conclusion, it is a suitable method also to evaluate the chronic consumption of ketamine, in addition to amphetamines in the same method of analysis.

An accidental fatal intoxication with methoxetamine

This paper reports an unintentional death involving the administration of methoxetamine [2-(3-methoxyphenyl)-2-(ethylamino)-cyclohexanone] and offers some reference values from living drug abusers. Methoxetamine is a new recreational drug with a similar structure to ketamine. The deceased was a 26-year-old male with a history of drug abuse; he was found lying on the floor in his apartment. Several "red-line" plastic bags were found, one of which was labeled "2-(3-methoxyphenyl)-2-(ethylamino)-cyclohexanone" and another labeled "Haze." In four cases from living subjects with unknown doses, concentrations of methoxetamine were found from 0.13 to 0.49 µg/g. In three of the cases, the blood samples also contained natural or synthetic cannabinoids. In the autopsy case, a considerably higher concentration of methoxetamine, 8.6 µg/g, was found in femoral blood. In addition, tetrahydrocannabinol and the three different synthetic cannabinoids AM-694, AM-2201, and JWH-018, were present in femoral blood. The circumstances and the high femoral blood concentration of methoxetamine point toward an unintentional, acute fatal intoxication with methoxetamine, although the presence of the three synthetic cannabinoids may have contributed to the death.

Fragmentation pathways of drugs of abuse and their metabolites based on QTOF MS/MS and MS(E) accurate-mass spectra

A study of the fragmentation pathways of several classes of drugs of abuse (cannabinoids, ketamine, amphetamine and amphetamine-type stimulants (ATS), cocaine and opiates) and their related substances has been made. The knowledge of the fragmentation is highly useful for specific fragment selection or for recognition of related compounds when developing MS-based analytical methods for the trace-level determination of these compounds in complex matrices. In this work, accurate-mass spectra of selected compounds were obtained using liquid chromatography coupled to quadrupole time-of-flight mass spectrometry, performing both MS/MS and MS(E) experiments. As regards fragmentation behavior, the mass spectra of both approaches were quite similar and were useful to study the fragmentation of the drugs investigated. Accurate-mass spectra of 37 drugs of abuse and related compounds, including metabolites and deuterated analogues, were studied in this work, and structures of fragment ions were proposed. The accurate-mass data obtained allowed to confirm structures and fragmentation pathways previously proposed based on nominal mass measurements, although new insights and structure proposals were achieved in some particular cases, especially for amphetamine and ATS, 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol (THC-COOH) and opiates.