Stefano Gentili

Simultaneous detection of amphetamine-like drugs with headspace solid-phase microextraction and gas chromatography-mass spectrometry.

A headspace solid-phase microextraction and gas chromatography-mass spectrometry (HS-SPME-GC-MS) procedure for the simultaneous detection of methylen-dioxyamphetamine (MDA), methylen-dioxymethamphetamine (MDMA), methylen-dioxyethamphetamine (MDE) and N-methyl-1-(1,3-benzodioxol-5-yl)-2-butanamine (MBDB) in hair has been developed. This method is suitable for the separation of primary and secondary amines, is reproducible, is not time consuming, requires small quantities of sample and does not require any derivatization. It provides sufficient sensitivity and specificity, with limits of detection (LOD) and limits of quantitation (LOQ) for each substance of <0.7 and 1.90 ng/mg, respectively. Intra- and inter-day precision were within 2 and 10%, respectively. This method is suitable for routine clinical, epidemiological and forensic purposes and can be used for the preliminary screening of many other substances (amphetamine, methamphetamine, ketamine, ephedrine, nicotine, phencyclidine, methadone) in hair and other biological matrices such as saliva, urine and blood. We also describe the first application of this HS-SPME-GC-MS procedure to the analysis of hair and saliva samples from young people attending a disco in the Rome area. All positive hair samples were confirmed by the gas chromatography-mass-mass (GC-MS(2)) technique in positive chemical ionization (PCI) mode. Some examples of the use of the method in detecting different drugs are reported.

Simple and reliable high-performance liquid chromatography fluorimetric procedure for the determination of amphetamine-derived designer drugs.

The paper describes a HPLC-fluorimetric procedure for the determination of methylenedioxyamphetamine, methylenedioxymethamphetamine, methylenedioxyethamphetamine and N-methyl-1-(1,3-benzodioxol-5-yl)-2-butanamine in urine, serum, saliva and street samples, that features interesting advantages over other procedures previously described. The method requires a very small sample volume (100 microl) and no extraction, lacks matrix effect, and is not time consuming. Linearity was in the range 50-1000 ng/ml regardless of matrix. Sensitivity and detection limit were 50 ng/ml and 10 ng/ml, respectively, but they may reach 10 ng/ml and 2 ng/ml if a slight modification is introduced in the procedure. Intra- and inter-day precision were always within 5% and 8%, respectively. Recovery was satisfactory for all matrices. The described procedure could be successfully used for clinical, epidemiological and forensic applications.

Determination of different recreational drugs in sweat by headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME GC/MS): Application to drugged drivers.

A procedure based on headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography/mass spectrometry (GC/MS) has been developed for the determination of most commonly used drugs of abuse in sweat of drivers stopped during roadside controls. DrugWipe 5A sweat screening device was used to collect sweat by a specific pad rubbed gently over forehead skin surface. The procedure involved an acid hydrolysis, a HS-SPME extraction for drugs of abuse but Δ(9)-tetrahydrocannabinol, which was directly extracted in alkaline medium HS-SPME conditions, a GC separation of analytes by a capillary column and MS detection by electron impact ionisation. The method was linear from the limit of quantification (LOQ) to 50ng drug per pad (r(2)≥0.99), with an intra- and inter-assay precision and accuracy always less than 15% and an analytical recovery between 95.1% and 102.8%, depending on the considered analyte. Using the validated method, sweat from 60 apparently intoxicated drivers were found positive to one or more drugs of abuse, showing sweat patches testing as a viable economic and simple alternative to conventional (blood and/or urine) and non conventional (oral fluid) testing of drugs of abuse in drugged drivers.

A Study on the Reliability of an On-Site Oral Fluid Drug Test in a Recreational Context

The reliability of DrugWipe 5A on site test for principal drugs of abuse (cannabis, amphetamines, cocaine, and opiates) detection in oral fluid was assessed by comparing the on-site results with headspace solid-phase microextraction (HS-SPME) gas chromatography-mass spectrometry (GC-MS) analysis on samples extracted by the device collection pad. Oral fluid samples were collected at recreational settings (e.g., discos, pubs, and music bars) of Rome metropolitan area. Eighty-three club goers underwent the on-site drug screening test with one device. Independently from the result obtained, a second device was used just to collect another oral fluid sample subsequently extracted and analyzed in the laboratory following HS-SPME procedure, gas chromatographic separation by a capillary column, and MS detection by electron impact ionization. DrugWipe 5A on-site test showed 54 samples (65.1%) positive to one or more drugs of abuse, whereas 75 samples (90.4%) tested positive for one or more substances following GC-MS assay. Comparing the obtained results, the device showed sensitivity, specificity, and accuracy around 80% for amphetamines class. Sensitivity (67 and 50%) was obtained for cocaine and opiates, while both sensitivity and accuracy were unsuccessful (29 and 53%, resp.) for cannabis, underlying the limitation of the device for this latter drug class.

Mitochondrial aspartate aminotransferase isoenzyme: A biochemical marker for the clinical management of alcoholics?

Serum mitochondrial and total aspartate aminotransferase activity was quantified by a characterized immunochemical method in 126 subjects, 44 healthy controls and 82 chronic alcoholics (51 outpatients and 31 monitored through 15 days). The monitored alcoholics were divided into actual abstinents (n = 21) and drinkers (n = 10) by blood ethanol concentration performed daily. The aims of the present study were: (a) to compare the diagnostic diagnostic usefulness of the mitochondrial isoenzyme and the mitochondrial/total aspartate aminotransferase ratio to detect problematic drinkers; (b) to evaluate the suitability of these indices to monitor abstinence, a difficulty not yet solved in the clinical management of alcoholics. The results demonstrated the mitochondrial isoenzyme to be more suitable to discriminate between controls and alcoholics (Kruskal and Wallis ANOVA, Bonferroni test, P < 10(-5) and mostly between actual drinkers and other alcoholics (P < 0.041). So acute alcohol consumption may be a significant, suggestive and until now inadequately examined factor in evaluating the suitability of mAST as a marker. The results, showing that mAST peaks quickly appear in the presence of a new alcohol intake, should indicate mAST as a possible marker of acute alcohol intake useful in checking self-claimed abstinence.

Purity and adulterant analysis of some recent drug seizures in Italy

The data collected in this study describe an initial attempt to systematically introduce the qualitative and quantitative analysis of adulterants present in seized street drugs in Italy with the aim of improving surveillance and data sharing and for this purpose, the implementation of validated and standardized procedures are essential.