Marcello Chiarotti

Simultaneous detection of some drugs of abuse in saliva samples by SPME technique

A simple method for the simultaneous determination of many drugs of abuse in saliva is referred [methadone, 2-ethyl-1,5-dimethyl-3,3-diphenylpyrrolinium perchlorate (EDDP), cocaine, cocaethylene, amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyethyl amphetamine (MDEA), N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine (MBDB), cannabidiol (CBD), Delta(9)-tetrahydrocannabinol (THC), cannabinol (CBN)]. Head space-solid phase microextraction (HS-SPME) and direct immersion-solid phase microextraction (DI-SPME) followed by gas chromatographic/mass spectrometric analyses (GC/MS) were employed, and results obtained with both techniques are discussed. The method was validated testing reproducibility, sensitivity, linearity.

Liquid chromatography/mass spectrometry analysis of exhaled leukotriene B4 in asthmatic children

BackgroundThe role of leukotriene (LT) B4, a potent inflammatory mediator, in atopic asthmatic and atopic nonasthmatic children is largely unknown. The lack of a gold standard technique for measuring LTB4 in exhaled breath condensate (EBC) has hampered its quantitative assessment in this biological fluid. We sought to measure LTB4 in EBC in atopic asthmatic children and atopic nonasthmatic children. Exhaled nitric oxide (NO) was measured as an independent marker of airway inflammation.MethodsFifteen healthy children, 20 atopic nonasthmatic children, 25 steroid-naïve atopic asthmatic children, and 22 atopic asthmatic children receiving inhaled corticosteroids were studied. The study design was of cross-sectional type. Exhaled LTB4 concentrations were measured using liquid chromatography/mass spectrometry-mass spectrometry (LC/MS/MS) with a triple quadrupole mass spectrometer. Exhaled NO was measured by chemiluminescence with a single breath on-line method. LTB4 values were expressed as the total amount (in pg) of eicosanoid expired in the 15-minute breath test. Kruskal-Wallis test was used to compare groups.ResultsCompared with healthy children [87.5 (82.5–102.5) pg, median and interquartile range], exhaled LTB4 was increased in steroid-naïve atopic asthmatic [255.1 (175.0–314.7) pg, p < 0.001], but not in atopic nonasthmatic children [96.5 (87.3–102.5) pg, p = 0.59)]. Asthmatic children who were receiving inhaled corticosteroids had lower concentrations of exhaled LTB4 than steroid-naïve asthmatics [125.0 (25.0–245.0) pg vs 255.1 (175.0–314.7) pg, p < 0.01, respectively]. Exhaled NO was higher in atopic nonasthmatic children [16.2 (13.5–22.4) ppb, p < 0.05] and, to a greater extent, in atopic steroid-naïve asthmatic children [37.0 (31.7–57.6) ppb, p < 0.001] than in healthy children [8.3 (6.1–9.9) ppb]. Compared with steroid-naïve asthmatic children, exhaled NO levels were reduced in asthmatic children who were receiving inhaled corticosteroids [15.9 (11.5–31.7) ppb, p < 0.01].ConclusionIn contrast to exhaled NO concentrations, exhaled LTB4 values are selectively elevated in steroid-naïve atopic asthmatic children, but not in atopic nonasthmatic children. Although placebo control studies are warranted, inhaled corticosteroids seem to reduce exhaled LTB4 in asthmatic children. LC/MS/MS analysis of exhaled LTB4 might provide a non-invasive, sensitive, and quantitative method for airway inflammation assessment in asthmatic children.

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.

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.

Analysis of 11-nor-9-carboxy-Δ9-tetrahydrocannabinol in biological samples by gas chromatography tandem mass spectrometry (GC/MS-MS)

Gas chromatography tandem mass spectrometry (GC/MS-MS) analysis of 11-nor-carboxy-delta(9)-tetrahydrocannabinol (delta(9)-THC-COOH), the major metabolite of delta(9)-tetrahydrocannabinol, in biological samples is reported. The proposed method, using deuterated delta(9)-THC-COOH as an internal standard, is able to detect the major metabolite of cannabis derivatives at very low levels (picograms/millilitre) with high specificity. These characteristics render the proposed analytical procedure suitable for confirmatory analysis in drug testing for cannabis use.

Drug distribution in the head, axillary and pubic hair of chronic addicts

This study investigates the distribution of some drugs in hair samples taken from different parts of the body (head, pubis and axillae). Samples drawn from 15 subjects who died from drug overdose were analysed. The concentrations of the drugs detected in the biological fluids did not appear to be correlated with those present in hair. The highest drug levels were observed in pubic hair. The concentration differences observed in the various types of hair can hypothetically be ascribed to a likely incorporation of the drugs from the outside.

Comparative analysis of illicit heroin samples

The comparative analysis of street heroin samples is still an object of scientific discussion. A combination of a wide range of analytical techniques is necessary to obtain a valid amount of information about the sample composition, and it is impossible to define an unique analytical approach. We suggest a complete analytical sequence based on analysis of volatile compounds, opiates, diluents, adulterants and metals, by head space gas chromatography (HS/GC), gas chromatography mass spectrometry (GC/MS), thin layer chromatography (TLC), high pressure liquid chromatography (HPLC) and atomic absorption (AA) using a sample amount as low as 50-100 mg. The outlined procedure can be successfully applied to routine work, thus obtaining suitable information about a samples chemical composition. This helps to attribute or exclude common sources of separate specimens. Results obtained on 33 street heroin samples confiscated in the metropolitan area of Rome are listed.

SEGMENTAL HAIR ANALYSIS FOR COCAINE AND HEROIN ABUSE DETERMINATION

Segmental hair analysis was performed to obtain information about the history of drug abuse of subjects in a rehabilitation programme. The analytical data from hair samples were correlated, when possible, with urine analysis and to toxicological anamnesis. Toxicological analysis of hair seems to be a valid tool in this specific field.

Overview on extraction procedures

The literature reviewed shows that many of the analytical problems related to the toxicological analysis of hair have been resolved, but in some cases, as for the application of the extraction methods, it is worth highlighting that the parameters must be carefully valued owing to the different operative options that are documented in the literature. Besides, the choice of a suitable extractive procedure may be influenced by various factors, including the following: (i) the type of drug which the analysis is targeted at and its characteristics of stability in different hydrolytic systems; (ii) ratio of distribution of the abused substances and their metabolites in the hair; and (iii) method used for the subsequent qualitative and quantitative analysis. Hence the selection of the extraction method requires some considerations, particularly when this kind of analysis is used in the forensic field. In this regard, emphasis is actually placed on pharmacokinetic incorporation and retention of drugs into hair. Furthermore, lacking any source of certified reference material, more studies concerning the recovery, accuracy and, if possible, quality control programs, could be implemented in order to test each procedure and improve the reliability of the extraction steps in the toxicological analysis of hair.

LC-MS-MS method for simultaneous determination of THCCOOH and THCCOOH-glucuronide in urine: Application to workplace confirmation tests

Cannabis is the one of the most frequently detected drug in workplace drug testing and in cases of driving under influence of drugs, and there is a greater demand for sensitive, rapid and reliable methods for confirming the presence of this drug in biological samples. This paper describes an LC-MS-MS procedure for direct analysis of cTHC and cTHC-glucuronide in urine, without hydrolysis of the samples or derivatisation. The sample preparation is very simple and consist only in a dilution of urine with methanol 1:1 (v/v) after adding the deuterated internal standard (cTHC-d3); then 10μl of the final solution is injected in LC-MS-MS. Chromatographic separation was performed using a reversed-phase column and gradient elution with 0.01% formic acid/acetonitrile/methanol and two MS-MS transitions for each substance were monitored. The method was fully validated and proved to be accurate (RSD <15%), precise (intra-day CV <10%) and sensitive with a limit of detection (LOD) of 5ng/ml for both the compounds studied. Linearity was tested in the range 5-1000ng/ml and the values of R(2) resulted >0.99. The developed method was applied to several authentic samples of urine which tested positive in the immunoassay screening and 98% of them was confirmed.