Claudia Vignali

Fully-automated systematic toxicological analysis of drugs, poisons, and metabolites in whole blood, urine, and plasma by gas chromatography–full scan mass spectrometry

The availability of automated, rapid and reliable methods for the systematic toxicological analysis (STA) of drugs and poisons in biosamples is of great importance in clinical and forensic toxicology laboratories. Gas chromatography-continuous scan mass spectrometry (GC-MS) possesses a high potential in STA because of its selectivity and identification power. However, in order to develop a fully automated STA method based on GC-MS two main obstacles have to be overcome: (a) sample preparation is rather sophisticated owing to the need to isolate analytes from the aqueous matrix and to allow a correct GC repartition of polar analytes; (b) the large amount of information collected within a single analysis makes it difficult to isolate relevant analytical information (mass spectra of analytes) from the chemical noise. Using a bench-top GC-MS system equipped with a laboratory robot for sample preparation (the Hewlett-Packard 7686 PrepStation) and an original method for mass spectral purification, a fully automated STA procedure was developed involving isolation of drugs from the sample (whole blood with minimal pretreatment, plasma, urine) by means of solid-phase extraction, derivatization (trimethylsilylation) of the acidic-neutral and of the basic extracts, GC-MS analysis, processing of data, and reporting of results. Each step of the procedure, and the method for data analysis in particular, can be easily integrated with other existing STA methods based on GC-MS.

Determination of opiates in hair. Effects of extraction methods on recovery and on stability of analytes

In order to evaluate (i) the recovery of extraction of opiates from authentic hair samples and (ii) the extent of hydrolysis of acetylated opiates (6-acetylmorphine, acetylcodeine) occurring during sample preparation, three different methods of extraction commonly used for opiates have been compared. To this purpose a sample consisting of a pool of hair collected from several heroin overdose cases has been submitted alternately to (A) digestion in 2 M NaOH at 80 degrees C for 1 h (n = 5), (B) incubation in 0.1 M HCl at 45 degrees C for 18 h (n = 5) and (C) incubation in methanol at 37 degrees C for 18 h (n = 5). After pH adjustment of the different incubation media to 7-8, analytes have been isolated by means of SPE using Bond Elut certify columns and derivatized with MSTFA. Analyses have been performed by either GC-MS in the selected ion monitoring mode or, omitting SPE, by radioimmunoassay. The extent of hydrolysis of 6-acetylmorphine to morphine and of acetylcodeine to codeine have been determined by submitting blank hair samples spiked with the acetylated analytes to the different extraction methods and measuring the amount of morphine and codeine formed. Both the recovery of extraction of the total morphine fraction (6-acetylmorphine + morphine) and the rate of hydrolysis of 6-acetylmorphine were found to be in the order: A > B > C. Similar results were obtained for the total codeine fraction (acetylcodeine + codeine). These results clearly indicate that: (i) the concentration of opiates measured in hair depends on the extraction method used; (ii) ratios between different analytes (e.g. 6-acetylmorphine vs. morphine) may reflect the rate of hydrolysis during sample preparation rather than different types of exposure to opiates.

Comparison of extraction procedures for benzodiazepines determination in hair by LC-MS/MS.

INTRODUCTION The use of a LC-MS/MS system for benzodiazepines detection remarkably increased the analytical sensitivity of these drugs in biological matrices, in particular in non-conventional ones such as hair. Since the amount of hair sample available for the analysis is frequently limited and, moreover, it needs to be checked for many other drugs and compounds of forensic interest, it is important to develop a sample preparation procedure able to detect either benzodiazepines and as many as possible other substances. The aim of this study was to compare the sensitivity of two different hair sample preparation procedures for benzodiazepines detection in hair. METHODS About 20mg hair, previously washed with organic solvent and cut into small pieces, were ultrasonicated with a phosphate buffer (pH 8.4) up to 1h and then extracted with dichloromethane/diethyl ether. The organic solvent was then dried under nitrogen flow and samples were reconstituted with 60μl methanol. Finally a 5μl aliquot was injected in the LC-MS/MS system. The second procedure consisted of an ultrasonication of hair samples in 700μl of methanol. Samples were then directly analyzed. Both the methods were fully validated. RESULTS Thirty-five compounds among benzodiazepines and their metabolites were screened using both the procedures. The methods fulfilled all the validation parameters and were applied on either spiked blank hair and real positive samples. While phosphate extraction allowed to reach a LOQ for almost all the substances ranging from 0.1 to 5pg/mg, thus guaranteeing to evaluate even a single dose administration (as confirmed by real positive cases) the sensitivity of the methanol extraction showed a LOQ ranging from 1 to 20pg/mg, still enough to assess a therapeutic use of almost all the benzodiazepines; yet the methanolic incubation allows a simple and rapid analytical procedure due to the direct injection of the extraction solvent. CONCLUSION Even though a methanol extraction procedure for benzodiazepines determination is useful for forensic toxicological purposes also when a wider range of substances is needed and in case of a small amount of hair available, it is advisable to prefer a phosphate extraction when detection of a single dose administration is required.

Simple and sensitive screening and quantitative determination of 88 psychoactive drugs and their metabolites in blood through LC-MS/MS: application on postmortem samples.

The aim of the study was to develop and validate a simple, sensitive and specific method for the detection and quantitative determination of 88 substances among psychoactive drugs and their metabolites in whole blood, and to apply the procedure to postmortem cases. Samples were consecutively diluted with methanol, acetonitrile and mobile phase. All the molecules were separated and then identified through a liquid chromatographic, tandem mass spectrometric system, and eventually fully validated according to the international guidelines. The method proved to be highly sensitive and specific and all the validation parameters fulfilled the acceptance criteria. In particular linearity was studied in the range LOQ-1000 ng/mL; matrix effects and carry over were negligible and the majority of the compounds assessed to be stable over several freeze and thaw processes. Olanzapine is the most unstable compound. Protryptiline and flupenthixol did not fulfilled acceptance criteria, and although their transitions were kept on the instrumental settings, they were not considered for the fully validation. The method was applied to several postmortem cases, and the results were compared to the GC-MS systematic toxicological analysis currently in use in our laboratory, assessing to be a good complementary procedure and providing a better sensitivity. The LC-MS/MS method could be easily applicable to routine analyses of postmortem samples, as well as to a screening procedure for clinical purposes; however it should be carried out in combination with a general unknown screening method.

Methadone-related deaths. A ten year overview

Over the last 10 years we have registered in our district (about 500,000 inhabitants) 36 cases of fatal methadone poisoning, involving both patients on treatment and naive subjects: this is a significant increase of deaths due to methadone use, misuse or abuse compared with previous years. Twenty-four patients (66.7%) were on methadone maintenance programs for heroin detoxification, while 12 (33.3%) were taking the drug without a medical prescription. The average blood concentration of methadone in patients undergoing a maintenance program was 1.06 mg/L (0.21-3.37 mg/L), against 0.79 mg/L (0.2-3.15 mg/L) in those taking the non-prescribed drug. Since 111 heroin-related deaths were recorded in our district in the same period, the fact that there appear to be many methadone deaths (about a third of heroin-related deaths) cannot be overlooked. The aim of this work is to understand the possible reasons for such a large number of methadone-related deaths. On this subject, we have noticed that risks associated with methadone intake are often underestimated by clinicians prescribing the drug: sometimes methadone is prescribed without taking into account patients tolerance to opiates, and a large number of subjects enrolled in methadone maintenance programs in Italy, have also been given take-home doses, thus increasing the risk of abuse and diversion.

Distribution of Embutramide and Mebezonium Iodide in a Suicide after Tanax Injection

Tanax is a veterinary formulation for euthanasia comprising embutramide, mebezonium iodide and tetracaine. A 37-year-old female was found dead on her bed, with three empty used syringes and a bottle of Tanax beside her body. Three needle puncture marks were observed on the body. The aim of this study was to evaluate the distribution of embutramide and mebezonium iodide in different biological matrices (femoral and cardiac blood, liver, muscle and vitreous humor) using a chromatographic method for the simultaneous determination of the two drugs. A direct and sensitive liquid chromatography-tandem mass spectrometry method was developed in multiple reaction monitoring mode with positive ionization. Lidocaine was used as an internal standard. Limits of detection and quantitation of 0.01 and 0.05 mg/L, respectively, were reached for both compounds. Embutramide levels ranged from 2.74 mg/L in vitreous humor to 5.06 mg/L in femoral blood, while mebezonium iodide was found at widely differing concentrations (ranging from 2.80 mg/kg in muscle to 24.80 mg/kg in liver). The chromatographic method developed for this study provides a very simple and sensitive means for the simultaneous determination of embutramide and mebezonium iodide, the emetic concentrations of which were consistent with suicides reported in the literature.

Workplace drug testing in Italy: findings about second-stage testing.

Workplace Drug Testing (WDT) in Italy includes two levels of monitoring: a first stage concerning drug testing on urine samples and a second involving both urine and hair analysis. The second stage is performed only on workers who tested positive at the first level. We analyzed urine and hair specimens from 120 workers undergoing second-level testing between 2009 and 2012. Eighty percent of them had tested positive for cannabinoids during the first level analysis, and 15.8% for cocaine. Both urine and hair samples were analyzed in order to find the following drugs of abuse: amphetamines, buprenorphine, cannabinoids, cocaine, ecstasy, methadone, and opiates. Urine analyses were performed by immunological screening (EMIT); urine confirmatory tests and hair analyses were performed by gas chromatography-mass spectrometry (GC-MS). As regards second-stage testing on urine samples, 71.2% of workers were always negative, whereas 23.9% tested positive at least once for cannabinoids and 2.5% for cocaine. Hair analyses produced surprising results: 61.9% of hair samples tested negative, only 6.2% tested positive for cannabinoids, whereas 28.8% tested positive for cocaine. These findings confirm that second-level surveillance of WDT, which includes hair analysis, is very effective because it highlights drug intake - sometimes heavy - that cannot be revealed only through urine analyses. The employees for whom drug addiction is proved can begin rehabilitation, while keeping their job. Eventually, our results confirmed the widespread and undeclared use of cocaine in Italy.

Distribution of venlafaxine and O-desmethylvenlafaxine in a fatal case

Venlafaxine is an extensively used antidepressant drug; it is considered to be quite safe and only a few pure cases of fatal poisoning have been reported. Here we describe a fatal case of venlafaxine self-poisoning including detailed tissue distribution of the drug and its metabolite O-desmethylvenlafaxine and the exact time sequence of events, as reported in the patients clinical record. Qualitative analyses were performed by GC-MS while quantitative analyses were carried out by LC-MS/MS. We then compared our results with those of previously published cases. Fatal venlafaxine poisoning often occurs after the intake of an extremely elevated number of tablets, corresponding to tens of grams of the drug, or it can be due to interaction between the drug and other substances. In the present case, no other drugs or ethanol were found and death occurred 12h after ingesting only 3g of venlafaxine, despite timely medical treatment.

The standardization of results on hair testing for drugs of abuse: An interlaboratory exercise in Lombardy Region, Italy

Hair testing for drugs of abuse is performed in Lombardy by eleven analytical laboratories accredited for forensic purposes, the most frequent purposes being driving license regranting and workplace drug testing. Individuals undergoing hair testing for these purposes can choose the laboratory in which the analyses have to be carried out. The aim of our study was to perform an interlaboratory exercise in order to verify the level of standardization of hair testing for drugs of abuse in these accredited laboratories; nine out of the eleven laboratories participated in this exercise. Sixteen hair strands coming from different subjects were longitudinally divided in 3-4 aliquots and distributed to participating laboratories, which were requested to apply their routine methods. All the participants analyzed opiates (morphine and 6-acetylmorphine) and cocainics (cocaine and benzoylecgonine) while only six analyzed methadone and amphetamines (amphetamine, methamphetamine, MDMA, MDA and MDEA) and five Δ(9)-tetrahydrocannabinol (THC). The majority of the participants (seven labs) performed acidic hydrolysis to extract the drugs from the hair and analysis by GC-MS, while two labs used LC-MS/MS. Eight laboratories performed initial screening tests by Enzyme Multiplied Immunoassay Technique (EMIT), Enzyme-linked Immunosorbent Assay (ELISA) or Cloned Enzyme Donor Immunoassay (CEDIA). Results demonstrated a good qualitative performance for all the participants, since no false positive results were reported by any of them. Quantitative data were quite scattered, but less in samples with low concentrations of analytes than in those with higher concentrations. Results from this first regional interlaboratory exercise show that, on the one hand, individuals undergoing hair testing would have obtained the same qualitative results in any of the nine laboratories. On the other hand, the scatter in quantitative results could cause some inequalities if any interpretation of the data is required.

Death after 25C-NBOMe and 25H-NBOMe consumption

A teenager male was found dead in a waterway after he was spotted jumping off into the water stream. The boy looked agitated and confused after a party with friends. At the gathering place, investigators seized packages of blotter papers. A complete autopsy and a histological evaluation of the main tissues were performed; although the death occurred by drowning, the prosecutor requested toxicological exams, in order to evaluate the potential role of drugs of abuse in the episode. Blood (both peripheral and central) and urine samples as well as seized blotter papers were collected and analyzed as follows. The blotter paper, analyzed through a GC-MS method, revealed the presence of 25-NBOMes. A liquid chromatography tandem mass spectrometric (LC-MS/MS) system was used to identify and quantify 5 different 25-NBOMes (namely 25B-NBOMe, 25C-NBOMe, 25D-NBOMe, 25H-NBOMe, 25I-NBOMe) in blood and urine. 25E-NBOMe was used as internal standard (IS). 1mL of urine and 1mL of blood (both peripheral and cardiac) were diluted in 2mL phosphate buffer at pH 6.0, containing IS and purified on a solid phase extraction (SPE) cartridge. LOD and LOQ for the five 25-NBOMes were calculated at 0.05 and 0.1ng/mL respectively. Linearity, accuracy, precision, ion suppression, carry over and recovery were tested and all parameters fulfilled the acceptance criteria. Blood and urine provided positive results for 25C-NBOMe and 25H-NBOMe. Eventually, the seized blotter papers were analyzed by means of LC-MS/MS and the presence of the two NBOMes was confirmed: 25C-NBOMe and 25H-NBOMe were measured at the concentration of 2.80 and 0.29ng/mL in peripheral blood, of 1.43 and 0.13ng/mL in central blood and of 0.94 and 0.14ng/mL in urine, respectively. THC and THCCOOH were also detected in biological fluids, at the concentration of 15.5 and 56.0ng/mL in peripheral blood, 9.9 and 8.5ng/mL in central blood, respectively. NBOMes can produce severe hallucination even at very low doses, and the 25C-NBOMe levels measured in the subjects blood are considered potentially toxic.