Journal of Chromatography B: Biomedical Sciences and Applications
Short communicationGas chromatographic–mass spectrometric detection of anhydroecgonine methyl ester (methylecgonidine) in human serum as evidence of recent smoking of crack
Introduction
The widespread abuse of cocaine has forensic implications, e.g., in crimes and in cases of driving under the influence of drugs. Cocaine is usually administered by nasal insufflation (snorting), injection or inhalation (smoking). The inhalation of the cocaine base (“crack”) exhibits basic differences when compared with the other routes of administration, e.g., under forensic aspects: (1) inhalation and snorting of cocaine leave no marks on the body like injections, (2) the occurrence of psychic effects after nasal application is substantially delayed (0.5 h) compared to injection or inhalation (few minutes), and (3) inhalation of cocaine [1] is supposed to have a higher potential for addiction [2], moreover, a higher rating for “high” and craving is reported [2].
Anhydroecgonine methyl ester (AEME, methylecgonidine) has been proposed as an analytical marker for heated cocaine [3], [4], [5], [6]. It is produced only in the process of smoking cocaine and is not formed metabolically. AEME has been detected in urine [3], [4], [5], [7], [8], saliva [5], [9], sweat [5] and hair [5], [7] from crack smokers but up to now it has only been detected in two blood samples from corpses [4]. The amount of AEME formed in the process of crack smoking is dependent on the temperature applied, 2% to 89% of a cocaine dose may reach the alveoli in the lungs as AEME [10]. It is excreted into urine, saliva and sweat indicating that significant amounts are absorbed into the blood circulation. This paper describes a sensitive procedure for the assay of AEME in blood/serum samples with gas chromatography–mass spectrometry (GC–MS); for the first time AEME concentrations in serum samples of living subjects are reported.
Section snippets
Chemicals, reference standards and apparatus
Solutions of the reference standards (1 mg/ml) cocaine (COC), benzoylecgonine (BZE), ecgoninemethylester (EME), AEME, anhydroecgonine (AE), ecgonine (ECG) and of the corresponding deuterated internal standards (0.1 mg/ml) cocaine-d3 (COC-d3), benzoylecgonine-d3 (BZE-d3) and ecgoninemethylester-d3 (EME-d3) were from Radian (Promochem, Wesel, Germany), the derivatization reagents N-methyl-N-(tert.-butyldimethylsilyl)trifluoroacetamide (MBDSTFA), N-methyl-N-(trimethylsilyl)trifluoroacetamide
Influence of the derivatization
In order to detect AEME (mass spectrum shown in Fig. 1) together with cocaine and its metabolites in serum, a derivatization step is necessary. Trimethylsilylation with BSTFA+1% trimethylchlorosilane (TMCS) is mainly used (e.g., Refs. [3], [4], [5]), since hydroxyl- and carboxylic groups of all cocaine metabolites are readily derivatized. AEME is not derivatized under these conditions, however, we found that with trimethylsilylation matrix compounds were eluted in the same time range as AEME,
References (19)
- et al.
J. Chromatogr. B
(1998) - et al.
J. Chromatogr. B
(1998) - et al.
Life Sci.
(1977) J. Anal. Toxicol.
(1995)- et al.
J. Pharmacol. Exp. Ther.
(1991) - et al.
Clin. Chem.
(1994) - et al.
J. Forensic Sci.
(1997) - et al.
Hum. Exp. Toxicol.
(1997) - et al.
J. Anal. Toxicol.
(1990)
Cited by (29)
Substance Misuse: Cocaine and Other Stimulants
2015, Encyclopedia of Forensic and Legal Medicine: Second EditionBehavioural, biochemical and molecular changes induced by chronic crack-cocaine inhalation in mice: The role of dopaminergic and endocannabinoid systems in the prefrontal cortex
2015, Behavioural Brain ResearchCitation Excerpt :Control mice were euthanized using the same procedure as treated mice, but no blood was collected from this group since AEME and cocaine metabolites would not be detected in those samples. BE and EME are the main cocaine metabolites, whereas AEME is produced exclusively by the pyrolysis of cocaine and is therefore used as an analytic marker of crack-cocaine use [22,23]. The prefrontal cortex was dissected, immediately frozen on dry ice and stored at −80 °C until RNA extraction.
Simultaneous analyses of cocaine, cocaethylene, and their possible metabolic and pyrolytic products
2006, Forensic Science InternationalDetermination of cocaine, its metabolites, pyrolysis products, and ethanol adducts in postmortem fluids and tissues using Zymark<sup>®</sup> automated solid-phase extraction and gas chromatography-mass spectrometry
2004, Journal of Chromatography B: Analytical Technologies in the Biomedical and Life SciencesChapter 23 Forensic analysis
2004, Journal of Chromatography LibraryArtifact production in the assay of anhydroecgonine methyl ester in serum using gas chromatography-mass spectrometry
2003, Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences