Biomedical subjects

Dirk W Lachenmeier

Publications and source records attributed to Dirk W Lachenmeier.

At least 19 recordsLinked to original sources

PubMed2007

Contribution of the fermenting yeast strain to ethyl carbamate generation in stone fruit spirits.

Fermented fruit and beverages frequently contain ethyl carbamate (EC), a potentially carcinogenic compound that can be formed by the reaction of urea with ethanol. Both are produced by the yeast Saccharomyces cerevisiae with ethanol as the major end product of hexose fermentation and urea as a by-product in arginine catabolism. In spirit production, EC can also be derived from cyanide introduced by stone fruit. To determine the relative contribution of yeast metabolism to EC production, we genetically engineered a diploid laboratory strain to reduce the arginase activity, thus blocking the pathway to urea production. For this purpose, strains with either a heterozygous CAR1/car1 deletion or a homozygous defect (car1/car1) were constructed. These strains were compared to the parental wild type and to an industrial yeast strain in cherry mash fermentations and spirit production. The strain with the homozygous car1 deletion showed a significant reduction of EC in the final spirits in comparison to the non-engineered controls. Nevertheless, using this strain for fermentation of stoneless cherry mashes did not completely impede EC formation. This indicates another, as yet unidentified, source for this compound.

Arginase↗

PubMed2006

Optimized LC/MS/MS analysis of morphine and codeine in poppy seed and evaluation of their fate during food processing as a basis for risk analysis.

The opiate alkaloids present in poppy seed intended for use in food recently have raised major concerns. An efficient method for routine analysis of morphine and codeine using liquid chromatography in combination with tandem mass spectrometry on a triple quadrupole instrument (LC/MS/MS) was therefore developed. The optimal sample preparation was found to be cold extraction of 10 g of unground poppy seed with 30 mL of methanol containing 0.1% acetic acid for 60 min shaken at 250 rpm. The fate of morphine during food processing was also studied. All experiments led to a significant reduction of morphine and codeine. For poppy cake only 16-50% of the morphine was recovered, and in poppy buns at the highest temperature (220 degrees C) only 3% of the original morphine content was found. Ground poppy seed showed significantly lower recoveries than untreated seed. Morphine elimination during food processing has to be taken into account in the current discussion about its maximum limits in poppy seed.

Chromatography, High Pressure Liquid↗

PubMed2006

Quantification of selected volatile constituents and anions in Mexican Agave spirits (Tequila, Mezcal, Sotol, Bacanora).

A large collection (n = 95) of Mexican Agave spirits with protected appellations of origin (Tequila, Mezcal, Sotol, and Bacanora) was analyzed using ion and gas chromatography. Because of their production from oxalate-containing plant material, all Agave spirits contained significant concentrations of oxalate (0.1-9.7 mg/L). The two Tequila categories ("100% Agave" and "mixed") showed differences in the methanol, 2-/3-methyl-1-butanol, and 2-phenylethanol concentrations with lower concentrations in the mixed category. Mezcal showed no significant differences in any of the evaluated parameters that would allow a classification. Sotol showed higher nitrate concentrations and lower 2-/3-methyl-1-butanol concentrations. Bacanora was characterized by exceptionally high acetaldehyde concentrations and a relatively low ethyl lactate content. The methanol content was the most problematic compound regarding the Mexican standards: two Tequilas (4%), five Sotols (31%), and six Bacanoras (46%) had levels above the maximum methanol content of 300 g/hL of alcohol. In conclusion, the composition of Mexican Agave spirits was found to vary over a relatively large range.

Agave↗

PubMed2006

Absinthism: a fictitious 19th century syndrome with present impact.

Absinthe, a bitter spirit containing wormwood (Artemisia absinthium L.), was banned at the beginning of the 20th century as consequence of its supposed unique adverse effects. After nearly century-long prohibition, absinthe has seen a resurgence after recent de-restriction in many European countries. This review provides information on the history of absinthe and one of its constituent, thujone. Medical and toxicological aspects experienced and discovered before the prohibition of absinthe are discussed in detail, along with their impact on the current situation. The only consistent conclusion that can be drawn from those 19th century studies about absinthism is that wormwood oil but not absinthe is a potent agent to cause seizures. Neither can it be concluded that the beverage itself was epileptogenic nor that the so-called absinthism can exactly be distinguished as a distinct syndrome from chronic alcoholism.The theory of a previous gross overestimation of the thujone content of absinthe may have been verified by a number of independent studies. Based on the current available evidence, thujone concentrations of both pre-ban and modern absinthes may not have been able to cause detrimental health effects other than those encountered in common alcoholism. Today, a questionable tendency of absinthe manufacturers can be ascertained that use the ancient theories of absinthism as a targeted marketing strategy to bring absinthe into the spheres of a legal drug-of-abuse. Misleading advertisements of aphrodisiac or psychotropic effects of absinthe try to re-establish absinthe's former reputation. In distinction from commercially manufactured absinthes with limited thujone content, a health risk to consumers is the uncontrolled trade of potentially unsafe herbal products such as absinthe essences that are readily available over the internet.

Journal Article↗

PubMed2006

Thujone--cause of absinthism?

Habitual abuse of the wormwood spirit absinthe was described in the 19th and 20th centuries as a cause for the mental disorder "absinthism" including the symptoms hallucinations, sleeplessness and convulsions. A controversial discussion is going on if thujone, a characteristic component of the essential oil of the wormwood plant Artemisia absinthium L., is responsible for absinthism, or if it was merely caused by chronic alcohol intoxication or by other reasons such as food adulterations. To ascertain if thujone may have caused absinthism, absinthes were produced according to historic recipes of the 19th century. Commercial wormwood herbs of two different manufacturers, as well as self-cultivated ones, were used in a concentration of 6 kg/100 l spirit. In addition, an authentic vintage Pernod absinthe from Tarragona (1930), and two absinthes from traditional small distilleries of the Swiss Val-de-Travers were evaluated. A GC-MS procedure was applied for the analysis of alpha- and beta-thujone with cyclodecanone as internal standard. The method was shown to be sensitive with a LOD of 0.08 mg/l. The precision was between 1.6 and 2.3%, linearity was obtained from 0.1 to 40 mg/l (r = 1.000). After the recent annulment of the absinthe prohibition all analysed products showed a thujone concentration below the maximum limit of 35 mg/l, including the absinthes produced according to historic recipes, which did not contain any detectable or only relatively low concentrations of thujone (mean: 1.3 +/- 1.6 mg/l, range: 0-4.3 mg/l). Interestingly, the vintage absinthe also showed a relatively low thujone concentration of 1.8 mg/l. The Val-de-Travers absinthes contained 9.4 and 1.7 mg/l of thujone. In conclusion, thujone concentrations as high as 260 mg/l, reported in the 19th century, cannot be confirmed by our study. With regard to their thujone concentrations, the hallucinogenic potential of vintage absinthes can be assessed being rather low because the historic products also comply with today's maximum limits derived to exclude such effects. It may be deduced that thujone plays none, or only a minor role in the clinical picture of absinthism.

Artemisia absinthium↗

PubMed2006

Automated determination of ethyl carbamate in stone-fruit spirits using headspace solid-phase microextraction and gas chromatography-tandem mass spectrometry.

A fully automated procedure using headspace solid-phase microextraction (HS-SPME) followed by gas chromatographic/tandem mass spectrometric (GC/MS/MS) detection was developed for the determination of the toxic contaminant ethyl carbamate (EC) in stone-fruit spirits. After addition of deuterated internal standard, the optimised HS-SPME extraction with carbowax/divinylbenzene fibres (30 min at 70 degrees C) was done applying salting out with sodium chloride in the presence of pH 7 buffer solution. For quantitative analysis the characteristic fragmentations of m/z 74>44 and m/z 62>44 for ethyl carbamate as well as m/z 64>44 for ethyl carbamate-d5 were monitored in the multiple reaction monitoring (MRM) mode using a triple quadrupole instrument. In the validation studies, ethyl carbamate exhibited good linearity with a regression coefficient of 0.998. The limits of detection and quantitation were 0.03 and 0.11 mg/l. The precision never exceeded 4.3% (intraday) and 8.2% (interday) at any of the concentrations examined. A good agreement of analysis results in comparison to conventional sample clean-up over diatomaceous earth columns was found (R = 0.956, Bias = 0.08 mg/l). The new HS-SPME/GC/MS/MS procedure is suitable for the fast, reliable and inexpensive determination of ethyl carbamate in alcoholic beverages in an automated, and therefore, convenient procedure.

Alcoholic Beverages↗

PubMed2006

Absinthe--a review.

The alcoholic beverage absinthe is recently experiencing a revival after a yearlong prohibition. This review article provides information on all aspects of this bitter spirit and its major components, especially wormwood (Artemisia absinthium L.), which contains the toxic monoterpene thujone. Over 100 references on historic and current literature are provided. The topics comprise the history of the alcoholic drink starting from its invention in the eighteenth century. Historical and modern recipes are discussed in the context of different quality categories and possibilities to reduce the content of thujone are given. The analytical techniques used to verify compliance with the maximum limit of thujone as well as further possibilities for quality control of absinthe are discussed. The toxicology of absinthe is reviewed with regard to the cause of a syndrome called "absinthism," which was described after chronic abuse of the spirit in the nineteenth century. Finally, a food regulatory and food chemical evaluation is provided and minimum requirements for absinthe are suggested. Absinthe should have a recognizable wormwood flavor and after dilution with water the characteristic clouding should arise (louche-effect). Products, which are advertized as being of premium grade should be made by distillation, should have an alcoholic strength of at least 45%vol, and should not contain artificial dye.

Absinthe↗

PubMed2005

Rapid screening for ethyl carbamate in stone-fruit spirits using FTIR spectroscopy and chemometrics.

Ethyl carbamate (EC, urethane, C2H5OCONH2) is a known genotoxic carcinogen of widespread occurrence in fermented food and beverages with the highest concentrations being found in stone-fruit spirits. Time-consuming procedures requiring extraction and gas chromatographic-mass spectrometric determination are regarded as reference procedures for the analysis of EC in alcoholic beverages. In this study, the rapid method of Fourier transform infrared (FTIR) spectroscopy in combination with partial least-squares (PLS) regression using selected wavelength bands is applied for the first time to the screening analysis of EC in stone fruit spirits (analysis time only 2 min). Apart from the actual content of EC in the sample, additional information was available from the FTIR spectra. This included data concerning the EC precursor hydrocyanic acid (HCN) and the maximum EC concentration which could be formed during storage. The PLS procedure was validated using an independent set of samples (Q(2) = 0.71-0.76, SEP = 0.42-0.67). The method was found to lack the accuracy required for a quantitative determination; it could only be used semi-quantitatively in the context of a screening analysis. If a rejection level of 0.8 mg L(-1) is applied as cut-off, overall correct classification rates of 85-91% for the calibration set and 77-85% for the validation set were achieved. False negative results can be avoided by lowering the cut-off to 0.6 mg L(-1). Through use of FTIR screening, 60-70% of all samples can be classified as negative and removed, leaving only conspicuous analysis results exceeding cut-off to be confirmed by complex and labour-intensive reference analyses.

Alcoholic Beverages↗

PubMed2005

Multivariate analysis of FTIR and ion chromatographic data for the quality control of tequila.

Principal component analysis (PCA) was applied to the chromatographic and spectroscopic data of authentic Mexican tequilas (n = 14) and commercially available samples purchased in Mexico and Germany (n = 24). The scores scatter plot of the first two principal components (PC) of the anions chloride, nitrate, sulfate, acetate, and oxalate accounting for 78% of the variability allowed a classification between tequilas bottled in Mexico and overseas; however, no discrimination between tequila categories was possible. Mexican products had a significantly (p = 0.0014) lower inorganic anion concentration (range = 1.5-5.1 mg/L; mean = 2.5 mg/L) than the products bottled in the importing countries (range = 3.3-62.6 mg/L; mean = 26.3 mg/L). FTIR allowed a rapid screening of density and ethanol as well as the volatile compounds methanol, ethyl acetate, propanol-1, isobutanol, and 2-/3-methyl-1-butanol using partial least-squares regression (precisions = 5.3-29.3%). Using PCA of the volatile compounds, a differentiation between tequila derived from "100% agave" (Agave tequilana Weber var. azul, Agavaceae) and tequila produced with other fermentable sugars ("mixed"tequila) was possible. The first two PCs describe 89% of the total variability of the data. Methanol and isobutanol influenced the variability in PC1, which led to discrimination. The concentrations of methanol and isobutanol were significantly higher (methanol, p = 0.004; isobutanol, p = 0.005) in the 100% agave (methanol, 297.9 +/- 49.5; isobutanol, 251.3 +/- 34.9) than in the mixed tequilas (methanol, 197.8 +/- 118.5; isobutanol, 151.4 +/- 52.8).

Agave↗

PubMed2005

Application of tandem mass spectrometry combined with gas chromatography to the routine analysis of ethyl carbamate in stone-fruit spirits.

Gas chromatography (GC) coupled to mass spectrometry (MS) operated in selected ion monitoring (SIM) mode is currently the method of choice for the determination of the toxic contaminant ethyl carbamate in alcoholic beverages. However, even after extensive sample cleanup over diatomaceous earth columns, the identity of ethyl carbamate often cannot be ascertained with confidence, due to inconsistent ratios of the SIM ions m/z 62, 74 and 44 because the qualifier ions are highly susceptible to interferences. Therefore, a new method combining GC and tandem MS using a triple-quadrupole instrument is introduced to determine ethyl carbamate in stone-fruit spirits. For quantitative analysis the characteristic transitions of m/z 74 --> 44 and m/z 62 --> 44 for ethyl carbamate as well as m/z 64 --> 44 for the deuterated internal standard ethyl carbamate-d5 were monitored in the multiple reaction monitoring (MRM) mode. In the validation studies, ethyl carbamate exhibited good linearity with a regression coefficient of 1.000. The limits of detection and quantitation were 0.01 and 0.04 mg/L. The recovery of the method was 100.4 +/- 9.4%. The precision never exceeded 7.8% (intraday) and 10.1% (interday) and the trueness never exceeded 11.3% (intraday) and 12.2% (interday) at any of the concentrations examined, indicating good assay accuracy. A good agreement of analytical results between a previously developed GC/MS SIM method and the GC/MS/MS MRM procedure was found (R=0.987). Regarding the validation data, the procedure is sensitive, selective and reproducible. The applicability of the developed method was demonstrated by the investigation of 70 stone-fruit spirits from commercial trade. The ethyl carbamate concentration of the samples ranged between 0.07 and 7.70 mg/L (mean 1.21 mg/L). The main advantage of the developed GC/MS/MS method is the reliability of the results without the need for time-consuming confirmatory analyses.

Alcoholic Beverages↗

PubMed2005

Retrospective trends and current status of ethyl carbamate in German stone-fruit spirits.

Ethyl carbamate (urethane, C(2)H(5)OCONH(2)) is a known genotoxic carcinogen of widespread occurrence in fermented food and beverages with highest concentrations found in stone-fruit spirits. Between 1986 and 2004, 631 cherry, plum or mirabelle (yellow plum) spirits were analysed for ethyl carbamate using gas chromatography in combination with mass spectrometry after extrelut extraction. The ethyl carbamate concentration of the samples ranged between 0.01 mg l(-1) and 18 mg l(-1) (mean 1.4 mg l(-1)). After exposure of the samples to UV light, significantly (p=0.001) higher concentrations between 0.01 mg l(-1) and 26 mg l(-1) (mean 2.3 mg l(-1)) were found. The ethyl carbamate concentration increased on average by 1.3 mg l(-1). A linear correlation between the year of sampling and ethyl carbamate concentration showed a statistically significant but very slight decrease (R=-0.10, p=0.024). However, if only samples which officially were non-compliant were considered exceeding the upper limit of 0.4 mg l(-1) more than twice, a significant reduction (R =-0.56, p=0.018) of the quota was evident. This shows that measures to reduce ethyl carbamate were successfully introduced in many distilleries. However, nearly 20 years after the first warnings about ethyl carbamate in spirit drinks, the problem persists especially in products derived from small distilleries. During experimental production of stone-fruit spirits using state-of-the-art technologies, it was shown that the occurrence of ethyl carbamate in stone fruit spirits is preventable. Even for small distilleries, simple possibilities like destoning exist to minimize the ethyl carbamate content.

Alcoholic Beverages↗

PubMed2005

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.

Adult↗

PubMed2004

Postmortem diagnosis of hypertonic dehydration.

Beside morphological signs of hypertonic dehydration as tinting of skin, sunken eyes, dry surface of the galea or dry cutting areas of organs, a chemical profile of vitreous humor was proposed as a diagnostic tool for the diagnosis of hypertonic dehydration. The profile consists of an elevation of sodium >155 mmol/l, chloride >135 mmol/l and urea >40 mg/dl. This profile was named dehydration pattern. The value of this dehydration pattern for the diagnosis of hypertonic dehydration will be discussed by a short review of the literature and case reports. So far, the published literature on the dehydration pattern is not a sound scientific basis for the diagnosis of dehydration.

Chlorides↗

PubMed2003

Determination of cannabinoids in hemp food products by use of headspace solid-phase microextraction and gas chromatography-mass spectrometry.

A fully automated procedure using alkaline hydrolysis and headspace solid-phase microextraction (HS-SPME), followed by on-fiber derivatization and gas chromatographic-mass spectrometric (GC-MS) detection has been developed for determination of cannabinoids in hemp food samples. After addition of a deuterated internal standard, the sample was hydrolyzed with sodium hydroxide and submitted to direct HS-SPME. After absorption of analytes for on-fiber derivatization, the fiber was placed directly into the headspace of a second vial containing N-methyl- N-trimethylsilyltrifluoroacetamide (MSTFA), before GC-MS analysis. Linearity was good for Delta(9)-tetrahydrocannabinol (THC), cannabidiol, and cannabinol; regression coefficients were greater than 0.99. Depending on the characteristics of the matrix the detection limits obtained ranged between 0.01 and 0.17 mg kg(-1) and the precision between 0.4 and 11.8%. In comparison with conventional liquid-liquid extraction this automated HS-SPME-GC-MS procedure is substantially faster. It is easy to perform, solvent-free, and sample quantities are minimal, yet it maintains the same sensitivity and reproducibility. The applicability was demonstrated by analysis of 30 hemp food samples. Cannabinoids were detected in all of the samples and it was possible to differentiate between drug-type and fiber-type Cannabis sativa L. In comparison with other studies relatively low THC concentrations between 0.01 and 15.53 mg kg(-1) were determined.

Cannabinoids↗

PubMed2003

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.

Cannabinoids↗

PubMed2003

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%).

Adolescent↗

PubMed2003

Application of tandem mass spectrometry combined with gas chromatography and headspace solid-phase dynamic extraction for the determination of drugs of abuse in hair samples.

A new method combination, headspace solid-phase dynamic extraction coupled with gas chromatography/tandem mass spectrometry (HS-SPDE/GC/MS/MS), is introduced to determine drugs of abuse in hair samples. This highly automated procedure utilizes SPDE for pre-concentration and on-coating derivatization as well as GC and triple quadrupole MS/MS for selective and sensitive detection. All these steps, apart from washing and cutting of the hair samples, are performed without manual intervention on a robot-like autosampler.SPDE is a solventless extraction technique related to solid-phase microextraction (SPME). The analytes are absorbed from the sample headspace directly into a hollow needle with an internal coating of polydimethylsiloxane by repeated aspirate/dispense cycles.The HS-SPDE/GC/MS/MS procedure was applied to the analysis of methadone, the trimethylsilyl derivatives of cannabinoids and the trifluoroacetyl derivatives of amphetamines and designer drugs. The method was shown to be sensitive with detection limits between 6 and 52 pg/mg hair matrix and precision between 0.4 and 7.8% by the use of an internal standard technique. Linearity was obtained from 0.1-20 ng/mg with coefficients of correlation between 0.995 and 0.999. Compared with conventional methods of hair analysis, HS-SPDE/GC/MS/MS is easier to use, substantially faster, with the degree of sensitivity and reproducibility demanded in clinical and forensic toxicology. The main advantage of the SPDE technique in relation to SPME is the robustness of the capillary.

Gas Chromatography-Mass Spectrometry↗

PubMed2002

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.

Amphetamines↗