Ana María Bermejo

Hair analysis for Δ9-THC, Δ9-THC-COOH, CBN and CBD, by GC/MS-EI: Comparison with GC/MS-NCI for Δ9-THC-COOH

A sensitive analytical method was developed for quantitative analysis of delta(9)-tetrahydrocannabinol (delta(9)-THC), 11-nor-delta(9)-tetrahydrocannabinol-carboxylic acid (delta(9)-THC-COOH), cannabinol (CBN) and cannabidiol (CBD) in human hair. The identification of delta(9)-THC-COOH in hair would document Cannabis use more effectively than the detection of parent drug (delta(9)-THC) which might have come from environmental exposure. Ketamine was added to hair samples as internal standard for CBN and CBD. Ketoprofen was added to hair samples as internal standard for the other compounds. Samples were hydrolyzed with beta-glucuronidase/arylsulfatase for 2h at 40 degrees C. After cooling, samples were extracted with a liquid-liquid extraction procedure (with chloroform/isopropyl alcohol, after alkalinization, and n-hexane/ethyl acetate, after acidification), which was developed in our laboratory. The extracts were analysed before and after derivatization with pentafluoropropionic anhydride (PFPA) and pentafluoropropanol (PFPOH) using a Hewlett Packard gas chromatographer/mass spectrometer detector, in electron impact mode (GC/MS-EI). Derivatized delta(9)-THC-COOH was also analysed using a Hewlett Packard gas chromatographer/mass spectrometer detector, in negative ion chemical ionization mode (GC/MS-NCI) using methane as the reagent gas. Responses were linear ranging from 0.10 to 5.00 ng/mg hair for delta(9)-THC and CBN, 0.10-10.00 ng/mg hair for CBD, 0.01-5.00 ng/mg for delta(9)-THC-COOH (r(2)>0.99). The intra-assay precisions ranged from <0.01 to 12.40%. Extraction recoveries ranged from 80.9 to 104.0% for delta(9)-THC, 85.9-100.0% for delta(9)-THC-COOH, 76.7-95.8% for CBN and 71.0-94.0% for CBD. The analytical method was applied to 87 human hair samples, obtained from individuals who testified in court of having committed drug related crimes. Quantification of delta(9)-THC-COOH using GC/MS-NCI was found to be more convenient than GC/MS-EI. The latter may give rise to false negatives due to the detection limit.

Use of solid-phase microextraction (SPME) for the determination of methadone and EDDP in human hair by GC–MS

Solid-phase microextraction (SPME) is a new extraction technique with many advantages: small sample volume, simplicity, quickness and solvent-free. It is mainly applied to environmental analysis, but is also useful for the extraction of drugs from biological samples. In this paper the use of SPME is proposed for the determination of methadone and its main metabolite EDDP in hair by GC-MS. The hair samples were washed, cut into 1-mm segments, and incubated with Pronase E for 12 h. A 100-micron polydimethylsiloxane (PDMS) film fibre was submerged for 30 min in a diluted solution of the hydrolysis liquid (1:4 with borax buffer) containing methadone-d3 and EDDP-d3 as internal standards. Once the microextraction was concluded the fibre was directly inserted into the CG injection port. Linearity was found for methadone and EDDP in the range studied, 1.0-50 ng/mg hair, with correlation coefficients higher than 0.99. Interassay relative standard deviation (R.S.D) was determined to be less than 13.30% for methadone and less than 8.94% for EDDP, at 3.0 and 30.0 ng/mg. Analytical recoveries were close to 100% for both compounds on spiked samples. The method was applied to the analysis of real hair samples from eight patients of a methadone maintenance programme. The concentration of methadone in hair ranged from 2.45 to 78.10 ng/mg, and for EDDP from 0.98 to 7.76 ng/mg of hair.

Evaluation of cocaine, amphetamines and cannabis use in university students through hair analysis: preliminary results.

The evaluation of drug abuse in a defined population was performed through toxicological hair analysis. Hair samples from university students ranging from 18 to 25 years of age were anonymously collected and screened for cocaine, amphetamines and cannabinoids by radioimmunoassay (RIA). Positive results (cut-off values adopted were 2 ng/mg for cocaine and amphetamines and 0.5 ng/mg for cannabinoids) were confirmed by GC/MS. Preliminary results showed 19% of positive results for cocaine on 200 samples analysed. No confirmed positive results were obtained for amphetamine analysis. RIA technique demonstrated its unsuitability for cannabinoids preliminary screening on hair, giving a high percent of false positive results.

Speciation of iron in breast milk and infant formulas whey by size exclusion chromatography-high performance liquid chromatography and electrothermal atomic absorption spectrometry.

Speciation of iron in milk was carried out by high performance liquid chromatography (HPLC) and electrothermal atomic absorption spectrometry (ETAAS). Milk whey was obtained and low molecular weight protein separation was performed by size exclusion chromatography (SEC) with a TSK Gel SW glass guard (Waters) pre-column and a TSK-Gel G2000 glass (Toso Haas) column. After studying water as a possible mobile phase, this mobile phase was carefully selected in order to avoid alterations of the sample and to make subsequent iron determination in the protein fractions easier by ETAAS. The proposed method is sensitive (limit of detection [LOD] and LOQ 1.4 and 4.7 microg l(-1), respectively) and precise (relative standard deviation [RSD]<10%). Iron is principally found in the proteins of 3 and 76 kDa in breast milk, and it is irregularly distributed in infant formulas.

Optimization of a rapid microwave-assisted extraction method for the simultaneous determination of opiates, cocaine and their metabolites in human hair

A rapid and cleanup-free microwave-assisted extraction (MAE) method is proposed for the simultaneous extraction of six illegal drugs of abuse - cocaine, benzoylecgonine (BZE), cocaethylene (CCE), morphine, 6-monoacethylmorphine (6AM) and codeine - from human hair samples. The analytes were determined using high performance liquid chromatography (HPLC) with photodiode array UV detection. The influence of several variables on the efficiency of the MAE procedure was investigated in detail by a multi-objective optimization approach based on a hybrid experimental design (17 experiments) and desirability functions. Six drugs were successfully extracted from human hair with recoveries close to 100% and good reproducibility (<3.6% RSD) under the optimal MAE conditions: 11 mL dichloromethane (DCM) extraction solvent, 60 degrees C extraction temperature, 9 min extraction time and 0.5 mL of methanol (MeOH) added to 50mg of the hair sample in the extraction vessels. Limits of quantification of 0.2 ng mg(-1) were found for the studied compounds. A comparison of sample preparation procedures, including MAE, enzymatic digestion and digestion by aqueous acids, was also conducted. The results indicated that the global behaviour of sample procedures provided similar satisfactory recoveries ranging from 86 to 100%. Indeed, the MAE procedure resulted in a reduction of extraction time by 100-fold and the elimination of cleanup steps. Slightly higher recoveries of morphine, 6AM, BZE and CCE, at 1 ng mg(-1) concentration level and cocaine at 40 ng mg(-1) concentration level, were achieved using MAE. Lastly, the proposed MAE method was applied to several human hair samples from multidrug abusers.

Determination of direct alcohol markers: a review

Alcohol is the most popular legal drug used in our society today, and its consumption by pregnant women remains an important public health problem. Gestational alcohol consumption can result in a continuum of adverse fetal outcomes known as fetal alcohol spectrum disorder (FASD). Effective strategies are needed to prevent the increasing adoption of risky drinking behaviors. Because ethanol itself is only measurable for a few hours after ethanol intake in conventional matrices including blood, urine, and sweat, these matrices are only useful to detect recent ethanol exposure. Since approximately early 2000, the non-oxidative ethanol metabolites have received increasing attention because of their specificity and, in some cases, wide time window of detection in non-conventional matrices including hair and meconium. In the attempt to update analytical methods for the determination of non-oxidative markers of alcohol, the objective of this study is to review published studies that measure fatty-acid ethyl esters (FAEE), ethyl glucuronide (EtG), and phosphatidylethanol (PEth) in alternative biological matrices, focusing on the extraction and detection methods and full analytical conditions used.

Matrix solid-phase dispersion on column clean-up/pre-concentration as a novel approach for fast isolation of abuse drugs from human hair

A simple and fast sample pre-treatment method based on matrix solid-phase dispersion (MSPD) for isolating cocaine, benzoylecgonine (BZE), codeine, morphine and 6-monoacethylmorphine (6-MAM) from human hair has been developed. The MSPD approach consisted of using alumina (1.80 g) as a dispersing agent and 0.6M hydrochloric acid (4 mL) as an extracting solvent. For a fixed hair sample mass of 0.050 g, the alumina mass to sample mass ratio obtained was 36. A previously conditioned Oasis HLB cartridge (2 mL methanol, plus 2 mL ultrapure water, plus 1 mL of 0.2M/0.2M sodium hydroxide/boric acid buffer solution at pH 9.2) was attached to the end of the MSPD syringe for on column clean-up of the hydrochloric acid extract and for transferring the target compounds to a suitable solvent for gas chromatography (GC) analysis. Therefore, the adsorbed analytes were directly eluted from the Oasis HLB cartridges with 2 mL of 2% acetic acid in methanol before concentration by N(2) stream evaporation and dry extract derivatization with N-methyl-tert-butylsilyltrifluoroacetamide (BSTFA) and chlorotrimethylsilane (TMCS). The optimization/evaluation of all the factors affecting the MSPD and on column clean-up procedures has led to a fast sample treatment, and analytes extraction and pre-concentration can be finished in approximately 30 min. The developed method has been applied to eight hair samples from poli-drug abusers and measured analyte concentrations have been found to be statistically similar (95% confidence interval) to those obtained after a conventional enzymatic hydrolysis method (Pronase E).

Screening for exogenous androgen anabolic steroids in human hair by liquid chromatography/orbitrap-high resolution mass spectrometry

A method for the screening of various anabolic steroids and their esters in human hair, based on liquid-chromatography-high resolution mass spectrometry using an Exactive benchtop Orbitrap mass spectrometer, has been set up and validated. This method involved methanolic incubation of 30 mg of hair and analysis of the relevant extract in HPLC using a C18 column. The mass detector, with nominal resolving power of 100,000, operated in full scan mode in APCI under positive ionization mode. Analytes were identified by exact mass, correspondence of isotopic cluster and retention times. The limits of detection obtained varied from 10 to 50 pg mg(-1), and limits of quantitation were 0.5 ng mg(-1) for all compounds. The method was linear for all analytes in the ranges from the LOQ to 6 ng mg(-1), giving correlation coefficients >0.99 for all analytes. Also accuracy (intended as %E) and repeatability (%CV) were always lower than 15%. Specificity was assessed by analysing ten blank samples and fifteen samples from polidrug abusers. This method was applied to a real-life case, resulting in the identification of testosterone undecanoate in the hair of a suspect. The analyte identity was confirmed by the analysis of its in-source fragmentation and comparison to a certified standard. Thanks to the scan acquisition, this method also enables retrospective re-analysis of the acquired datafile in case a further analyte needs to be screened.

Electrospray ionization tandem mass spectrometry for the simultaneous determination of opiates and cocaine in human hair.

A fast and highly sensitive electrospray ionization tandem mass spectrometry (ESI-MS/MS) method has been developed for the simultaneous determination of morphine, 6-methylacetylmorphine (6-MAM), codeine, cocaine and benzoylecgonine (BZE) in hair from drug abusers. Pulverized hair samples were subjected to an optimized matrix solid phase dispersion (MSPD) procedure with alumina, followed by diluted hydrochloric acid elution on column solid-phase extraction (SPE) clean-up/pre-concentration. Alternatively, samples were also subjected to an optimized ultrasound assisted enzymatic hydrolysis (USEH) with Pronase E, followed by an off-line SPE clean up/pre-concentration procedure. Positive electrospray ionization and multiple reaction monitoring (MRM) with one precursor ion/product ion transition were used for the identification and quantification (deuterated analogues of each target as internal standards) of each analyte. The chromatographic pump and the autosampler were used for injecting the standards and the hair extracts (20 μL) as a flow injection analysis mode. The highest sensitivity was achieved when delivering the targets with an acetonitrile/water/formic acid (80/19.875/0.125) mixture. The limits of detection of the method were 39.2, 4.4, 6.8, 7.0 and 7.4 ng g(-1) for morphine, 6-MAM, codeine, cocaine and BZE, respectively. Relative standard deviations of intra- and inter-day precision were lower than 9 and 12%, respectively; whereas, analytical recoveries ranged from 96±5 to 106±4%. The developed method (MSPD-ESI-MS/MS) was applied to different hair samples from polydrug abusers, and results were statistically compared to those obtained after a conventional gas chromatography-mass spectrometry (GC-MS) analysis and also after USEH and ESI-MS/MS or GC-MS determinations.

A rapid method for the extraction, enantiomeric separation and quantification of amphetamines in hair

This paper presents a rapid and sensitive method for the determination and chiral separation of amphetamines and related designer drugs in hair samples. The substances are extracted from hair matrix by a 30 min treatment with a saturated carbonate buffer at pH 10 under ultrasonication. A commercial chiral derivatizing agent, trifluoroacetyl-prolyl chloride, is then added to the solution that is directly extracted with hexane and subsequently analyzed by GC/MS in SIM mode. R and S isomers of amphetamine, methamphetamine, MDA, MDMA and MDEA can be separated and detected with a limit of detection of 0.1 ng/mg for amphetamine, methamphetamine and MDA, and of 0.2 ng/mg for MDMA and MDEA. The method was then applied to 12 samples from suspected amphetamines abusers, showing the presence of both isomers of amphetamine and MDMA in one sample (27 and 1.5 ng/mg, respectively) and of MDMA in further eight samples, in concentrations ranging from traces to 2.7 ng/mg. No differences were observed in the disposition of different isomers in hair.