Concentration profiles of cocaine, pyrolytic methyl ecgonidine and thirteen metabolites in human blood and urine: determination by gas chromatography-mass spectrometry

When cocaine is smoked, a pyrolytic product, methyl ecgonidine (anhydroecgonine methyl ester), is also consumed with the cocaine. The amount of methyl ecgonidine formed depends on the pyrolytic conditions and composition of the illicit cocaine. This procedure describes detection of cocaine and 10 metabolites--cocaethylene, nor-cocaine, nor-cocaethylene, methyl ecgonine, ethyl ecgonine, benzoylecgonine, nor-benzoylecgonine, m-hydroxybenzoylecgonine, p-hydroxybenzoylecgonine and ecgonine--in blood and urine. In addition, the detection of pyrolytic methyl ecgonidine and three metabolites--ecgonidine (anhydroecgonine), ethyl ecgonidine (anhydroecgonine ethyl ester) and nor-ecgonidine (nor-anhydroecgonine)--are included. The newly described metabolites, ethyl ecgonidine and nor-ecgonidine, were synthesized and characterized by gas chromatography-mass spectrometry (GC-MS). All 15 compounds were extracted from 3 mL of blood or urine by solid-phase extraction and identified by a GC-MS method. The overall recoveries were 49% for methyl ecgonine, 35% for ethyl ecgonine, 29% for ecgonine and more than 83% for all other drugs. The limits of detection were between 0.5 and 4.0 ng/mL except for ecgonine, which was 16 ng/mL. Linearity for each analyte was established and in all cases correlation coefficients were 0.9985-1.0000. The procedure was applied to examine the concentration profiles of analytes of interest in post-mortem (PM) blood and urine, and in urine collected from living individuals (LV). These specimens previously were shown to be positive for the cocaine metabolite, benzoylecgonine. Ecgonidine, the major metabolite of methyl ecgonidine, was present in 77% of PM and 88% of the LV specimens, indicating smoking as the major route of cocaine administration. The new pyrolytic metabolites, ethyl ecgonidine and nor-ecgonidine, were present in smaller amounts. The urine concentrations of nor-ecgonidine were 0-163 ng/mL in LV and 0-75 ng/mL in PM specimens. Ethyl ecgonidine was found only in PM urine at concentrations 0-39 ng/mL. Ethanol-related cocaine metabolites, ethyl ecgonine or cocaethylene, were present in 69% of PM and 53% of cocaine-positive LV specimens, implying alcohol consumption with cocaine use. The four major metabolites of cocaine--benzoylecgonine, ecgonine, nor-benzoylecgonine and methyl ecgonine--constituted approximately 88 and 97% of all metabolites in PM and LV specimens, respectively. The concentrations of nor-cocaine and nor-cocaethylene were consistently the lowest of all cocaine metabolites. At benzoylecgonine concentrations below 100 ng/mL, ecgonine was present at the highest concentrations. In 20 urine specimens, benzoylecgonine and ecgonine median concentrations (range) were 54 (0-47) and 418 ng/mL (95-684), respectively. Therefore, detection of ecgonine is advantageous when benzoylecgonine concentrations are below 100 ng/mL.     

Metabolism of synthetic cannabinoids PB-22 and its 5-fluoro analog, 5F-PB-22, by human hepatocyte incubation and high-resolution mass spectrometry

Background

PB-22 (1-pentyl-8-quinolinyl ester-1H-indole-3-carboxylic acid) and 5F-PB-22 (1-(5-fluoropentyl)-8-quinolinyl ester-1H-indole-3-carboxylic acid) are new synthetic cannabinoids with a quinoline substructure and the first marketed substances with an ester bond linkage. No human metabolism data are currently available, making it difficult to document PB-22 and 5F-PB-22 intake from urine analysis, and complicating assessment of the drugs’ pharmacodynamic and toxicological properties.

Methods

We incubated 10 μmol/l PB-22 and 5F-PB-22 with pooled cryopreserved human hepatocytes up to 3 h and analyzed samples on a TripleTOF 5600+ high-resolution mass spectrometer. Data were acquired via TOF scan, followed by information-dependent acquisition triggered product ion scans with mass defect filtering (MDF). The accurate mass full scan MS and MS/MS metabolite datasets were analyzed with multiple data processing techniques, including MDF, neutral loss and product ion filtering.

Results

The predominant metabolic pathway for PB-22 and 5F-PB-22 was ester hydrolysis yielding a wide variety of (5-fluoro)pentylindole-3-carboxylic acid metabolites. Twenty metabolites for PB-22 and 22 metabolites for 5F-PB-22 were identified, with the majority generated by oxidation with or without glucuronidation. For 5F-PB-22, oxidative defluorination occurred forming PB-22 metabolites. Both compounds underwent epoxide formation followed by internal hydrolysis and also produced a cysteine conjugate.

Conclusion

Human hepatic metabolic profiles were generated for PB-22 and 5F-PB-22. Pentylindole-3-carboxylic acid, hydroxypentyl-PB-22 and PB-22 pentanoic acid for PB-22, and 5′-fluoropentylindole-3-carboxylic acid, PB-22 pentanoic acid and the hydroxy-5F-PB-22 metabolite with oxidation at the quinoline system for 5F-PB-22 are likely the best targets to incorporate into analytical methods for urine to document PB-22 and 5F-PB-22 intake.

Validation of a novel method to identify in utero ethanol exposure: simultaneous meconium extraction of fatty acid ethyl esters,ethyl glucuronide,and ethyl sulfate followed by LC-MS/MS quantification

Presence of fatty acid ethyl esters (FAEE), ethyl glucuronide (EtG), and ethyl sulfate (EtS) in meconium, the first neonatal feces, identifies maternal alcohol consumption during pregnancy. Current meconium alcohol marker assays require separate analyses for FAEE and EtG/EtS. We describe development and validation of the first quantitative liquid chromatography tandem mass spectrometry assay for 9 FAEEs, EtG, and EtS in 100 mg meconium. For the first time, these alcohol markers are analyzed in the same meconium aliquot, enabling comparison of the efficiency of gestational ethanol exposure detection. 100 mg meconium was homogenized in methanol and centrifuged. The supernatant was divided, and applied to two different solid phase extraction columns for optimized analyte recovery. Limits of quantification for ethyl laurate, myristate, linolenate, palmitoleate, arachidonate, linoleate, palmitate, oleate, and stearate ranged from 25–50 ng/g, with calibration curves to 2,500–5,000 ng/g. EtG and EtS linear dynamic ranges were 5–1,000 and 2.5–500 ng/g, respectively. Mean bias and between-day imprecision were <15 %. Extraction efficiencies were 51.2–96.5 %. Matrix effects ranged from ?84.7 to 16.0 %, but were compensated for by matched deuterated internal standards when available. All analytes were stable (within ±20 % change from baseline) in 3 authentic positive specimens, analyzed in triplicate, after 3 freeze/thaw cycles (?20 °C). Authentic EtG and EtS also were stable after 12 h at room temperature and 72 h at 4 °C; some FAEE showed instability under these conditions, although there was large inter-subject variability. This novel method accurately detects multiple alcohol meconium markers and enables comparison of markers for maternal alcohol consumption.

Cannabinoids in oral fluid by on-site immunoassay and by GC-MS using two different oral fluid collection devices

Oral fluid (OF) enables non-invasive sample collection for on-site drug testing, but performance of on-site tests with occasional and frequent smokers’ OF to identify cannabinoid intake requires further evaluation. Furthermore, as far as we are aware, no studies have evaluated differences between cannabinoid disposition among OF collection devices with authentic OF samples after controlled cannabis administration. Fourteen frequent (≥4 times per week) and 10 occasional (less than twice a week) adult cannabis smokers smoked one 6.8 % ?⁹-tetrahydrocannabinol (THC) cigarette ad libitum over 10 min. OF was collected with the StatSure Saliva Sampler, Oral-Eze, and Draeger DrugTest 5000 test cassette before and up to 30 h after cannabis smoking. Test cassettes were analyzed within 15 min and gas chromatography–mass spectrometry cannabinoid results were obtained within 24 h. Cannabinoid concentrations with the StatSure and Oral-Eze devices were compared and times of last cannabinoid detection (t _last) and DrugTest 5000 test performance were assessed for different cannabinoid cutoffs. 11-nor-9-Carboxy-THC (THCCOOH) and cannabinol concentrations were significantly higher in Oral-Eze samples than in Stat-Sure samples. DrugTest 5000 t _last for a positive cannabinoid test were median (range) 12 h (4–24 h) and 21 h (1–?≥?30 h) for occasional and frequent smokers, respectively. Detection windows in screening and confirmatory tests were usually shorter for occasional than for frequent smokers, especially when including THCCOOH ≥20 ng L^?1 in confirmation criteria. No differences in t _last were observed between collection devices, except for THC ≥2 μg L^?1. We thus report significantly different THCCOOH and cannabinol, but not THC, concentrations between OF collection devices, which may affect OF data interpretation. The DrugTest 5000 on-site device had high diagnostic sensitivity, specificity, and efficiency for cannabinoids.     

Oral fluid/plasma cannabinoid ratios following controlled oral THC and smoked cannabis administration

Oral fluid (OF) is a valuable biological alternative for clinical and forensic drug testing. Evaluating OF to plasma (OF/P) cannabinoid ratios provides important pharmacokinetic data on the disposition of drug and factors influencing partition between matrices. Eleven chronic cannabis smokers resided on a closed research unit for 51 days. There were four 5-day sessions of 0, 30, 60, and 120 mg oral ?⁹-tetrahydrocannabinol (THC)/day followed by a five-puff smoked cannabis challenge on Day 5. Each session was separated by 9 days ad libitum cannabis smoking. OF and plasma specimens were analyzed for THC and metabolites. During ad libitum smoking, OF/P THC ratios were high (median, 6.1; range, 0.2–348.5) within 1 h after last smoking, decreasing to 0.1–20.7 (median, 2.1) by 13.0–17.1 h. OF/P THC ratios also decreased during 5-days oral THC dosing, and after the smoked cannabis challenge, median OF/P THC ratios decreased from 1.4 to 5.5 (0.04–245.6) at 0.25 h to 0.12 to 0.17 (0.04–5.1) at 10.5 h post-smoking. In other studies, longer exposure to more potent cannabis smoke and oromucosal cannabis spray was associated with increased OF/P THC peak ratios. Median OF/P 11-nor-9-carboxy-THC (THCCOOH) ratios were 0.3–2.5 (range, 0.1–14.7) ng/μg, much more consistent in various dosing conditions over time. OF/P THC, but not THCCOOH, ratios were significantly influenced by oral cavity contamination after smoking or oromucosal spray of cannabinoid products, followed by time-dependent decreases. Establishing relationships between OF and plasma cannabinoid concentrations is essential for making inferences of impairment or other clinical outcomes from OF concentrations.     

Differential inhibition of postnatal brain,spinal cord and body growth by a growth hormone antagonist

Background  

Growth hormone (GH) plays an incompletely understood role in the development of the central nervous system (CNS). In this study, we use transgenic mice expressing a growth hormone antagonist (GHA) to explore the role of GH in regulating postnatal brain, spinal cord and body growth into adulthood. The GHA transgene encodes a protein that inhibits the binding of GH to its receptor, specifically antagonizing the trophic effects of endogenous GH.     

Transfer measurements for the Ti+Ni systems at near barrier energies

Large enhancements have been observed in the sub-barrier fusion cross sections for Ti+Ni systems in our previous studies. Coupled channel calculations incorporating couplings to 2⁺ and 3⁻ states failed to explain these enhancements completely. A possibilty of transfer channels contributing to the residual enhancements had been suggested. In order to investigate the role of relevant transfer channels, measurements of one- and two-nucleon transfer were carried out for ^46,48Ti+⁶¹Ni systems. The present paper gives the results of these studies.