Determination of cannabinoids in 50 μL whole blood samples by online extraction using turbulent flow chromatography and LC-HRAM-Orbitrap-MS: Application on driving under the influence of drugs cases

The analysis of cannabinoids in whole blood is usually done by traditional mass spectrometry (MS) techniques, after offline cleanup or derivatization steps which can be lengthy, laborious, and expensive. We present a simple, fast, highly specific, and sensitive method for the determination of Δ9 -tetrahydrocannabinol (THC), cannabidiol (CBD), cannabinol (CBN), 11-hydroxy-Δ9 -tetrahydrocannabinol (11-OH-THC), and 11-nor-9-carboxy-Δ9 -tetrahydrocannabinol (THC-COOH) in 50 μL whole blood samples. After the addition of deuterated internal standards (IS) and a simple protein precipitation step, an online extraction of sample supernatants using turbulent flow chromatography (TurboFlow-Thermo Scientific) was carried out. Analytes were separated on a C18 analytical column and detected by LC-HRAM-Orbitrap-MS using a Thermo Scientific Q Exactive Focus MS system. MS detection was performed in polarity switching and selected ion monitoring (SIM) modes using five specific acquisition windows, at a resolution of 70,000 (FWHM). Total run time was about 10 min including preanalytical steps. Method validation was carried out by determining limit of detection (LOD), lower limit of quantitation (LLOQ), linearity range, analytical accuracy, intra-assay and interassay precision, carry-over, matrix effect, extraction recovery, and selectivity, for all analytes. Measurement uncertainties were also evaluated, and a decision rule was set with confidence for forensic purposes. The method may become suitable for clinical and forensic toxicology applications, taking advantage of the small matrix volume required, the simple and cost-effective sample preparation procedure, and the fast analytical run time. Performances were monitored over a long-term period and tested on 7620 driving under the influence of drugs (DUID) samples, including 641 positive samples.

Analytical Characterization of 3-MeO-PCP and 3-MMC in Seized Products and Biosamples: The Role of LC-HRAM-Orbitrap-MS and Solid Deposition GC-FTIR

Among the phencyclidine (PCP) and synthetic cathinone analogs present on the street market, 3-methoxyphencyclidine (3-MeO-PCP) is one of the most popular dissociative hallucinogen drugs, while 3-methylmethcathinone (3-MMC) is a commonly encountered psychostimulant. Numerous 3-MeO-PCP- and 3-MMC-related intoxication cases have been reported worldwide. Identification of the positional isomers of MeO-PCP and MMC families are particularly challenging for clinical and forensic laboratories; this is mostly due to their difficult chromatographic separation (particularly when using liquid chromatography–LC) and similar mass spectrometric behaviors. 3-MeO-PCP and 3-MMC were identified in two powders, detained by two subjects and seized by the police, by different analytical techniques, including liquid chromatography-high-resolution accurate-mass Orbitrap mass spectrometry (LC-HRAM-Orbitrap-MS), and solid deposition gas chromatography-Fourier transform infrared spectroscopy (sd-GC-FTIR). LC-HRAM-Orbitrap-MS allowed us to assign the elemental formulae C₁₈H₂₇NO (MeO-PCP) and C₁₁H₁₅NO (MMC) through accurate mass measurement of the two MH⁺ ions, and the comparison of experimental and calculated MH⁺ isotopic patterns. However, MH⁺ collision-induced product ions spectra were not conclusive in discriminating between the positional isomers [(3-MeO-PCP vs. 4-MeO-PCP) and (3-MMC vs. 4-MMC and 2-MMC)]. Likewise, sd-GC-FTIR easily allowed us to differentiate between the MeO-PCP and MMC positional isomers unambiguously, confirming the presence of 3-MeO-PCP and 3-MMC, due to the high-quality match factor of the experimental FTIR spectra against the target FTIR spectra of MeO-PCP and MMC isomers in a dedicated library. 3-MeO-PCP (in contrast to 3-MMC) was also detected in blood and urine samples of both subjects and analyzed in the context of routine forensic casework by LC-HRAM-Orbitrap-MS following a simple deproteinization step. In addition, this untargeted approach allowed us to detect dozens of phase I and phase II 3-MeO-PCP metabolites in all biological specimens. Analysis of the extracted samples by sd-GC-FTIR revealed the presence of 3-MeO-PCP, thus confirming the intake of such specific methoxy-PCP isomer in both cases. These results highlight the effectiveness of LC-HRAM-Orbitrap-MS and sd-GC-FTIR data in attaining full structural characterization of the psychoactive drugs, even in absence of reference standards, in both non-biological and biological specimens.

Characterization of the designer drug deschloroketamine (2-methylamino-2-phenylcyclohexanone) by gas chromatography/mass spectrometry, liquid chromatography/high-resolution mass spectrometry, multistage mass spectrometry, and nuclear magnetic resonance

RATIONALE

Clinical and forensic toxicology laboratories are challenged every day by the analytical aspects of the new psychoactive substances phenomenon. In this study we describe the analytical characterization of a new ketamine derivative, deschloroketamine (2-methylamino-2-phenylcyclohexanone), contained in seized powders.

METHODS

The analytical techniques employed include gas chromatography/mass spectrometry (GC/MS), liquid chromatography/electrospray ionization coupled with Orbitrap high-resolution/MS (LC/ESI-HRMS), multistage MS (ESI-MS(n)), and NMR. The LC/ESI-HRMS analyses consisted of accurate mass measurements of MH(+) ions in full-scan mode; comparison of experimental and calculated MH(+) isotopic patterns; and examination of the isotopic fine structure (IFS) of the M + 1, M + 2, M + 3 isotopic peaks relative to the monoisotopic M + 0 peak. The collision-induced product ions of the MH(+) ions were studied by both HRMS and MS(n). (1)H and (13)C NMR measurements were carried out to confirm the chemical structure of the analyte.

RESULTS

The EI mass spectra obtained by GC/MS analysis showed the presence of molecular ions at m/z 203, and main fragment ions at m/z 175, 174, 160, 147, 146, and 132. The application of LC/ESI-HRMS allowed us to obtain: the accurate mass of deschloroketamine MH(+) ions with a mass accuracy of 1.47 ppm; fully superimposable experimental and calculated MH(+) isotopic patterns, with a relative isotopic abundance value of 3.69 %; and the IFS of the M + 1, M + 2, M + 3 isotopic peaks completely in accordance with theoretical values. Examination of the product ions of MH(+), as well as the study of both (1)H and (13)C NMR spectra, enabled the full characterization of the molecular structure of deschloroketamine.

CONCLUSIONS

The combination of the employed analytical techniques allowed the characterization of the seized psychoactive substance, in spite of the lack of a reference standard. Deschloroketamine is a ketamine analogue considered to be more potent and longer lasting than ketamine, and this paper is probably the first to report on its analytical characterization.

Pneumatically assisted desorption/ionization: 1. Some thoughts on the possible ionization mechanism(s)

We have observed that spraying solvent droplets on a zopiclone tablet produced MH(+) ions also in the absence of any electrical field and without the addition of organic acids to the sprayed solvent. The choice of a drug tablet as test bench has been done for the signal stability, higher than that observed when the drug is directly placed on a stainless steel surface. This behavior indicates that the formation of MH(+) ions is mainly due to pneumatical effects and the results are discussed with respect to those obtained by other research groups. Different mechanisms contributing to MH(+) production under these conditions are proposed and discussed. The local heating of the solvent thin layer present on the surface has been calculated and the small temperature increase (and the consequent small decrease of pK(a) value) suggests that this effect can play only a minor role. However, different solvents have been employed for studying this aspect and, quite surprisingly, the best results have been obtained with acetonitrile (ACN). Experiments performed by spraying CD(3)CN showed again the formation of MH(+) and not MD(+), and this excludes the role of ACN as protonating medium. A further thought was stimulated by the behavior observed by varying the sheath gas (N(2)) flow, showing that the MH(+) ion intensity increases by increasing the flow. Side effects related to the highest kinetic energy of the spraying droplets can be considered, but an active role of N(2) in the MH(+) formation could be taken into account, by considering the possible ionization of N(2) by collisional phenomena. The N(2)(+*) ions could undergo a charge-exchange reaction with analyte molecules leading to a short-lived odd electron ion which behaves as protonating media for neutral molecules. The above-described mechanism does not require either the presence of electrical fields nor the addition of organic acid to the sprayer solvent and can give a rationale for what was observed when only pneumatical conditions are employed.

A case of beta-carboline alkaloid intoxication following ingestion of Peganum harmala seed extract

Beta-carboline alkaloids harmine, harmaline, and tetrahydroharmine can stimulate the central nervous system by inhibiting the metabolism of amine neurotransmitters, or by direct interaction with specific receptors; they are found in numerous plants, including Peganum harmala, Passiflora incarnata and Banisteriopsis caapi, and in the entheogen preparation Ayahuasca, which is traditionally brewed using B. caapi to enhance the activity of amine hallucinogenic drugs. The ingestion of plant preparations containing beta-carboline alkaloids may result in toxic effects, namely visual and auditory hallucinations, locomotor ataxia, nausea, vomiting, confusion and agitation. We report a case of intoxication following intentional ingestion of P. harmala seed infusion; P. harmala seeds were bought over the Internet. The harmala alkaloids were identified by gas chromatography-mass spectrometry in the seed extract and the patient's urine. This is, to our knowledge, the first case of P. harmala intoxication corroborated by toxicological findings.

An improved method for cyanide determination in blood using solid-phase microextraction and gas chromatography/mass spectrometry

A new method is described for the qualitative and quantitative analysis of cyanide, a very short-acting and powerful toxic agent, in human whole blood. It involves the conversion of cyanide into hydrogen cyanide and its subsequent headspace solid-phase microextraction (HS-SPME) and detection by gas chromatography/mass spectrometry (GC/MS) in selected ion monitoring (SIM) mode. Optimizing the conditions for the GC/MS (type of column, injection conditions, temperature program) and SPME (choice of SPME fiber, effect of salts, adsorption and desorption times, adsorption temperature) led to the choice of a 75-microm carboxen/polydimethylsiloxane SPME fiber, with D3-acetonitrile as internal standard, and a capillary GC column with a polar stationary phase. Method validation was carried out in terms of linearity, precision and accuracy in both aqueous solutions and blood. The limit of detection (LOD) and limit of quantitation (LOQ) were determined only in aqueous solutions. The assay is linear over three orders of magnitude (water 0.01-10, blood 0.05-10 microg/mL); and the LOD and LOQ in water were 0.006 and 0.01 microg/mL, respectively. Good intra- and inter-assay precision was obtained, always <8%. The method is simple, fast and sensitive enough for the rapid diagnosis of cyanide intoxication in clinical and forensic toxicology.

Evaluation of T-cell receptor CD3+ gamma delta in gestational diabetes mellitus

Few studies have shown a significant increase of CD3+ T-cell receptor (TCR) gamma delta in the early phases of type 1 diabetes. We wished to determine if CD3+ TCR gamma delta is involved in the pathogenesis of gestational diabetes mellitus (GDM). We studied 29 GDM patients and 21 normal pregnant women. Lymphocyte subpopulations (CD3+ TCR alpha beta, CD3+ TCR gamma delta), islet cell antibodies (ICA), glutamic acid decarboxylase antibodies (GAD) and protein tyrosine phosphatase antibodies (IA2-Ab) were evaluated in all patients. The percentage of CD3+ TCR gamma delta was significantly higher in GDM women than in the control group (5.1 +/- 2.9% vs 3.7 +/- 1.7%; p < 0.05). No abnormalities of the other lymphocyte subpopulations were found. All subjects were negative for ICA; 2 GDM patients were positive for GAD, but no relationship was found between GAD positivity and CD3+ gamma delta levels in these 2 patients. Further follow-up studies of these patients are required to verify if the CD3+ TCR gamma delta receptor is a useful marker for diabetes development.

A study on lymphocyte subpopulation in diabetic mothers at delivery and in their newborn

Despite the importance of immunological aspects in pregnancy, until now few studies have been reported on the cellular immune modifications of diabetic pregnancy and on the newborn of diabetic mothers. Therefore, we thought it of interest to evaluate cell immunity in diabetic pregnant women and in their newborn children. Fourteen pregnant women with Type 1 diabetes (T1DM), mean age (+/-SD) 30-4 yr, mean disease duration (+/-SD) 12+/-5 yr, 15 with gestational diabetes mellitus (GDM) (mean age 33+/-6 yr), and 21 healthy pregnant women (mean age 29+/-4 yr) were studied and their metabolic and immunological parameters were evaluated. Fifty newborn babies were examined for immunological evaluation. Mean fasting plasma glucose and HbA1c values were higher in T1DM and GDM patients than in controls. Total lymphocyte subsets were higher in T1DM and GDM patients, although there were no significant differences between the percentual values. In children of T1DM and GDM mothers absolute lymphocyte values were increased, whereas the natural killer (NK) subset had decreased values in both absolute and percentual terms. Our work shows that, with respect to healthy controls, both GDM and T1DM mothers have a significant increase in total lymphocytes, and newborns have a reduced number of NK lymphocytes. Lower numbers of NK lymphocytes are probably related to altered production of lymphokines during foetal life and may also represent a real immune deficit in monitoring against viral infections.

Cytokines modulate MIA PaCa 2 and CAPAN-1 adhesion to extracellular matrix proteins

Variations in cancer cell adhesion to extracellular matrix (ECM) proteins might underlie an enhanced metastatic potential. ECM binding is mediated by cell-adhesion molecules, the membrane expression of which might be influenced by soluble mediators, such as cytokines. The aims of our study were to ascertain whether epidermal growth factor (EGF), transforming growth factor beta1 (TGF-beta1), interleukin 1alpha (IL-1alpha), or interleukin 1beta (IL-1beta) can modify MIA PaCa 2 (pancreatic cancer cell line) and CAPAN-1 (metastatic pancreatic cancer cell line) adhesion to fibronectin, laminin, or type I collagen, and whether these cytokines can shift the membrane expression of the hyaluronic acid receptor (CD44). EGF significantly enhanced MIA PaCa 2, but not CAPAN-1, adhesion to fibronectin, laminin, and type I collagen. TGF-beta1 reduced MIA PaCa 2 adhesion to type I collagen, but enhanced CAPAN-1 adhesion to fibronectin and laminin. IL-1alpha was found to enhance MIA PaCa 2 adhesion to fibronectin, while reducing adhesion to type I collagen, whereas IL-1beta reduced the adhesion to laminin. IL-1alpha enhanced CAPAN-1 adhesion to laminin in a dose-dependent manner; IL-1beta slightly increased the adhesion of these cells to laminin at low dosage, and to type I collagen at high dosage. Both IL-1alpha and IL-1beta reduced CD44 membrane expression of MIA PaCa 2, while TGF-beta1 increased the percentage of CD44-positive CAPAN-1 cells. We suggest that the effects on cell adhesion induced by different cytokines depend on the status of the target pancreatic cancer cell. EGF and, in part, IL-1alpha can favor nonmetastatic pancreatic cancer cell adhesion to ECM, possibly favoring tumor spread. Metastatic cells seem to lose the responsiveness to EGF, while becoming hyperresponsive to IL-1alpha. TGF-beta1 might exert an antidiffusive effect on primary, and a prodiffusive effect on metastatic pancreatic cancer cells. Only IL-1alpha, IL-1beta, and TGF-beta1 seem to influence CD44 membrane expression. All the results presented in this study were obtained in vitro, and in vivo studies are needed to verify whether the studied cytokines can favor or counteract pancreatic cancer spread.

Identification of local Th2 and Th0 lymphocytes in vernal conjunctivitis by cytokine flow cytometry

PURPOSE

Th2 lymphocytes may play a key role in the development of allergic diseases such as vernal keratoconjunctivitis (VKC). Cytokine flow cytometry of tear samples was used to identify the phenotypical and functional properties of lymphocytes at the actual site of the allergic reaction.

METHODS

Tear and blood samples were obtained from patients affected by active VKC (n = 12) and from normal control subjects (n = 10). Tears were obtained after gentle scraping of the tarsal and bulbar conjunctiva. Tear and blood samples were placed in a solution of brefeldin-A, phorbol myristate acetate (PMA), ionomycin, and RPMI for 4 hours and then processed for flow cytometry. Lymphocytes were marked with the monoclonal antibodies, anti-IFN-gamma and anti-interleukin (IL)-4. Levels of IL-4, IL-2, IFN-gamma, IL-2R, total IgE, eosinophil cationic protein (ECP), eosinophil protein X/neurotoxin (EPX), and myeloperoxidase (MPO) were also evaluated in serum.

RESULTS

Expression of IL-4 was observed in 9.2%+/-9.5% of lymphocytes in tears of patients with VKC. Of the 12 patients with VKC, 8 (67%) had tear lymphocytes positive for IL-4 (Th2). Two patients (17%) had a double population of lymphocytes: One was positive for Th2, and the other was positive for both IL-4 and IFN-gamma (Th0). One patient (8%) was positive for IFN-gamma (Th1) only, and one patient was negative for both ILs. No differences in the percentage of Th2 lymphocytes were found between tarsal and limbal patients. The percentage of Th2 lymphocytes was significantly correlated with the severity of the disease. No positive lymphocytes were found in tears of control subjects. Eosinophils, serum IgE, ECP, and EPX were all significantly higher in VKC than in control subjects.

CONCLUSIONS

In ocular allergic diseases, local lymphocytes expressed the Th2 phenotype and, to a lesser degree, the Th0 phenotype. Although results of systemic allergic markers can be inconclusive in patients with VKC, flow cytometry demonstrated a local lymphocyte phenotype that can account for the clinical and histologic abnormalities of VKC.

Polymorphonuclear oxidative burst after Helicobacter pylori water extract stimulation is not influenced by the cytotoxic genotype but indicates infection and gastritis grade

H. pylori-associated gastric mucosal inflammation is characterized by the presence of polymorphonuclear (PMN) leukocyte infiltrate, which is more severe when the infecting strain is cagA positive. After appropriate stimuli, such as bacterial products, PMN release large amounts of oxygen derived free radicals and proteases, to kill the bacterium. H. pylori seems to be particularly resistant to the oxidative machinery of PMN, which can in turn damage the host gastric mucosa. We evaluated peripheral PMN oxidative burst response after stimulation with water extracts from cagA positive (WEcagA+) or negative (WEcagA-) H. pylori strains in infected (n=31) and non-infected patients (n=32) in comparison with healthy controls (n=16); the influence of gastric mucosal inflammatory infiltrate and activity grade on PMN oxidative burst were also assessed. PMN oxidative burst was measured by FACS analysis. H. pylori water extracts were obtained from bacterial culture. H. pylori genotype was determined by means of the polymerase chain reaction. The PMN oxidative burst in H. pylori infected patients was significantly higher than that in H. pylori negative or healthy controls, no differences being found when the results following WEcagA+ and WEcagA- stimulation were compared. The difference in PMN oxidative burst obtained after WEcagA- and E. coli (standard stimulus for PMN oxidative burst) stimulation discriminated H. pylori infected from non-infected patients with a sensitivity of 90% and a specificity of 97%. The grade of PMN oxidative burst correlated with PMN infiltration grade of the gastric mucosa. Our findings allow to conclude that PMN oxidative burst activation by H. pyloriWE is species- but not strain-correlated. PMN priming, probably consequent to the action of soluble mediators released by mononuclear cells, makes PMN hyper-responsive to H. pylori products, thus favoring the release in the gastric mucosa of infected patients of large amounts of oxygen-derived free radicals, which are not enough to eliminate the infection, but may contribute to damaging the gastric mucosa itself. Peripheral PMN oxidative burst response to H. pyloriWE might furthermore be of help in diagnosing H. pylori infection.