Dirk W. Lachenmeier

Automated headspace solid-phase dynamic extraction for the determination of amphetamines and synthetic designer drugs in hair samples

The technique of automated headspace solid-phase dynamic extraction (SPDE) coupled with gas chromatography-mass spectrometry was evaluated for the determination of amphetamines and synthetic designer drugs in hair samples. Headspace SPDE is a novel method for the solventless extraction of organic compounds in aqueous samples. In a so-called inside needle capillary absorption trap a hollow needle with an internal coating of polydimethylsiloxane is used as extraction and preconcentration medium. Sampling is performed on the solution headspace by passing the gas through the device actively by a syringe. Analytes present in the sample are sorbed onto the deposited stationary phase. The syringe needle is placed into the injection port of a GC and rapid heating of the metal needle induces the desorption of analytes. For the determination of amphetamine, methamphetamine, 3,4-methylendioxyamphetamine (MDA), 3,4-methylendioxymethamphetamine, 3,4-methylendioxyethylamphetamine (MDEA), 3,4-methylendioxyphenyl-2-butanamine and N-methyl-1-(3,4-methylendioxyphenyl)-2-butanamine in human hair samples, 10 mg of hair were hydrolysed with sodium hydroxide. After absorption of analytes for an on-coating derivatization procedure the SPDE needle was directly placed into the headspace of a second vial containing N-methyl-bis(trifluoroacetamide). A validation procedure revealed absolute analyte recoveries between 10.2 and 16.7%. Linearity was obtained from 0.1 to 20 ng/mg with coefficients of correlation between 0.992 and 0.999. Intra- and inter-day precision were determined at two different concentrations and resulted in ranges between 1.4 and 4.1% (intra-day) and 4.2-14.6% (inter-day). Limits of detection between 0.03 ng/mg (MDA) and 0.19 ng/mg (MDEA) were achieved. Results indicated that SPDE is a rapid and sensitive method for the analysis of biological samples. Compared to solid-phase microextraction we found a higher extraction rate coupled with a faster automated operation.

Automated headspace solid-phase dynamic extraction for the determination of cannabinoids in hair samples.

This article describes a fully automated procedure for detecting cannabinoids in human hair samples. The procedure uses alkaline hydrolysis and headspace solid-phase dynamic extraction (HS-SPDE), followed by on-coating derivatization and gas chromatography-mass spectrometry (GC-MS). SPDE is a further development of solid-phase microextraction (SPME), based on an inside needle capillary absorption trap. It uses a hollow needle with an internal coating of polydimethylsiloxane as extraction and pre-concentration medium. Ten mg of hair were washed with deionised water, petroleum ether and dichloromethane. After adding deuterated internal standards, the sample was hydrolyzed with sodium hydroxide and directly submitted to HS-SPDE. After absorption of analytes for an on-coating derivatization procedure, the SPDE-needle was directly placed into the headspace of a second vial containing N-methyl-N-trimethylsilyl-trifluoroacetamide before GC-MS analysis. The limit of detection was 0.14 ng/mg for Delta(9)-tetrahydrocannabinol, 0.09 ng/mg for cannabidiol, and 0.12ng/mg for cannabinol. Absolute recoveries were in the range of 0.6 to 8.4%. Linearity was verified over a range from 0.2 to 20 ng/mg, with coefficients of correlation between 0.998 and 0.999. Intra- and inter-day precision were determined at two different concentrations and resulted in ranges between 2.3 and 6.0% (intra-day) and 3.3 and 7.6% (inter-day). Compared with conventional methods of hair analysis, this automated HS-SPDE-GC-MS procedure is substantially faster. It is easy to perform without using solvents and with minimal sample quantities, and it yields the same sensitivity and reproducibility. Compared to SPME, we found a higher extraction rate, coupled with a faster automated operation and greater stability of the device.

Systematic regional study of dopamine, norsalsolinol, and (R/S)-salsolinol levels in human brain areas of alcoholics

BACKGROUND Dopamine (DA)-derived tetrahydroisoquinolines (TIQs) are discussed as neurochemical factors of addiction processes in alcoholism. In a prospective study, the regional distribution of DA, (R)-salsolinol (SAL), and (S)-SAL, as well as norsalsolinol (NorSAL) was examined systematically in a large collective of human brain samples obtained by autopsy. METHODS The material comprises 44 brains of alcoholics and 47 controls with 6 standardized specimens in each case. The analytes were determined after solid-phase extraction and enantioselective derivatization using gas chromatography-mass spectrometry. RESULTS Levels of DA, (R/S)-SAL, and NorSAL in alcoholics did not differ significantly from those of the control group. A relationship between alcohol consumption and SAL formation could not be proved. Topical differences and no ubiquitous occurrence were encountered. Significant amounts of (R)-SAL and (S)-SAL as well as NorSAL only were found in DA-rich areas of the basal ganglia, whereas in other regions of the brain, no TIQs were detected. Especially in the nucleus caudatus, the concentrations of DA, SAL, and NorSAL decreased significantly with rising age. CONCLUSION These findings do not support the hypothesis that one of the SAL enantiomers or NorSAL is involved in the genesis of alcoholism. However, they suggest that the concentration of the substrate DA may determine the alkaloid level during in vivo formation. The revealed data can serve as reference for other studies in humans concerning the cause of alcoholism or other neurodegenerative diseases with the involvement of TIQs.

Methadone substitution: medicolegal problems in Germany

In Germany, the substitution of methadone for heroin abusers has arisen recently and has resulted in various medicolegal problems. Normally, these concern methadone-associated deaths, or the prescription of methadone resulting in criminal prosecutions concerning physicians. Not to be forgotten is the problem of driving while taking methadone. In the years 1997-2001, we detected methadone in the blood of 398 cases that were analysed by the Institute of Legal Medicine, Bonn. Methadone was the only drug in only 18 cases. In most of the cases, up to five additional drugs were also being taken: benzodiazepines (61%), ethanol (40%), morphine (39%), cannabinoids (35%), cocaine (28%), anti-depressants (3%), and amphetamines (2%).

Dose-Concentration Relationships of Methadone and EDDP in Hair of Patients on a Methadone-Maintenance Program

After controlled oral administration of d,l-methadone solution (15–260 mg/day) in the context of a methadone-maintenance program, concentrations of methadone and 2-ethylidine-1,5-dimethyl-3,3-diphenyl-l-pyrrolidine (EDDP), in head hair were determined (N=41), using a fully automated headspace solid-phase microextraction procedure in combination with gas chromatography and mass spectrometry (HS-SPME/GC/MS).Methadone was present in all samples in concentrations ranging from 0.25 to 13.29 ng/mg (mean 2.69±0.45 ng/mg). EDDP was also present in every sample in concentrations ranging from 0.05 to 2.17 ng/mg (mean 0.43±0.08). The concentration ratio methadone/EDDP was 7.5±5.7 in the proximal segments, but decreased to 4.8±1.4 in the distal segments. A statistically significant correlation between the intake dose and the methadone and EDDP concentrations in the subjects’ hair could be established only in the proximal segments (r=0.913 for methadone and r=0.901 for EDDP), but not in the distal segments. In all, 131 segments analyzed, the correlation coefficient was r=0.760 for methadone and r=0.738 for EDDP. In comparison to the dose-concentration relationship reported in the literature, we found a better correlation with higher correlation coefficients especially in the proximal segments.However, owing to a broad distribution in the correlation between dosage and concentration, the determination of methadone and EDDP in hair holds only limited information about prior methadone administration.