Quantitation of hexahydrocannabinol (HHC) and metabolites in blood from DUID cases.

Hexahydrocannabinol (HHC) was first reported in the EU in May 2022. HHC has three chiral carbon atoms, but only (6aR,9R,10aR)-HHC (9R-HHC) and (6aR,9S,10aR)-HHC (9S-HHC) have been encountered in HHC products. The aim of this study was to develop and validate a method for the quantitative analysis of 9R-HHC, 9S-HHC, 11-OH-9R-HHC, 9R-HHC-COOH, 9S-HHC-COOH and 8-OH-9R-HHC. In addition, an objective was to investigate the immunochemical cross-reactivity. Blood samples from driving under the influence of drugs (DUID) cases screened positive for cannabis using enzyme-linked immunoadsorbent assay (ELISA) and confirmed negative for tetrahydrocannabinol (THC), 11-hydroxy-THC and THC-COOH were reanalyzed with a newly validated HHC method to investigate the presence of HHC and metabolites. The LC-MS-MS method was validated for matrix effects, lower limit of quantification (LLOQ), calibration model, precision, bias and autosampler stability. Cross-reactivity on an ELISA method was investigated separately for 9R-HHC-COOH and 9S-HHC-COOH at a concentration range between 5 and 200 ng/mL. The cross-reactivity was found to be 120% for 9R-HHC-COOH and 48% for 9S-HHC-COOH. In the LC-MS-MS method, 9R-HHC-COOH, 9S-HHC-COOH and 11-OH-9R-HHC showed matrix effects <25% at both concentrations, while 8-OH-9R-HHC, 9R-HHC and 9S-HHC matrix effects exceeded 25% at both concentrations but showed good precision (<10% for both inter and intra day) and low bias (<6%) in the further validation. The LLOQ was investigated and established at 0.2 ng/mL for all analytes except the carboxylated metabolites that had an LLOQ of 2.0 ng/mL. The upper LOQ was 20 and 200 ng/mL, respectively. Reanalysis of cases (n = 145) confirmed HHC and metabolites in 32 cases (22%). It was determined that the major metabolite in blood after administration of HHC was 9R-HHC-COOH followed by 11-OH-9R-HHC and that presumptive positive cases are caught by the routine ELISA screening for cannabis.

Rilmazafone: A designer benzodiazepine pro-drug involved in fatal intoxications.

Rilmazafone is a pro-drug that can be prescribed in Japan to treat insomnia. Rilmazafone metabolizes into active compounds by a ring closure resulting in a triazolo benzodiazepine structure similar to alprazolam. In mid-2022, the National Board of Forensic Medicine in Sweden were requested to investigate two separate deaths with the suspected use of pagoclone. Packages labeled "Pagoclone" were found at each scene that was suspected to contain rilmazafone based on website information. During screening by high resolution mass spectrometry, rilmazafone metabolites were presumptively identified. Due to the lack of reference material for the active metabolites, the metabolites were synthesized in house and quantification of the compounds identified in the two autopsy cases was prompted. In Case 1, femoral blood concentrations of 7.9, 65 and 170 ng/g of the metabolites rilmazolam, N-desmethyl rilmazolam and di-desmethyl rilmazolam, respectively, were detected. Additional toxicological findings included the medications haloperidol, alimemazine, fluoxetine, olanzapine and acetaminophen. In Case 2, femoral blood concentrations of 1.7, 1.4 and 70 ng/g of rimazolam, N-desmethyl rilmazolam and di-desmethyl rilmazolam, respectively, were detected. Additional toxicological findings included loperamide, alimemazine and pregabalin. The intake of rilmazafone was determined as the cause of death in Case 1 and contributed in the Case 2.

Quantitative analysis of drugs in hair by UHPLC high resolution mass spectrometry.

Liquid chromatographic methods coupled to high resolution mass spectrometry are increasingly used to identify compounds in various matrices including hair but there are few recommendations regarding the parameters and their criteria to identify a compound. In this study we present a method for the identification and quantification of a range of drugs and discuss the parameters used to identify a compound with high resolution mass spectrometry. Drugs were extracted from hair by incubation in a buffer:solvent mixture at 37°C during 18h. Analysis was performed on a chromatographic system comprised of an Agilent 6550 QTOF coupled to a 1290 Infinity UHPLC system. High resolution accurate mass data were acquired in the All Ions mode and exported into Mass Hunter Quantitative software for quantitation and identification using qualifier fragment ions. Validation included selectivity, matrix effects, calibration range, within day and between day precision and accuracy. The analytes were 7-amino-flunitrazepam, 7-amino-clonazepam, 7-amino-nitrazepam, acetylmorphine, alimemazine, alprazolam, amphetamine, benzoylecgonine, buprenorphine, diazepam, ethylmorphine, fentanyl, hydroxyzine, ketobemidone, codeine, cocaine, MDMA, methadone, methamphetamine, morphine, oxycodone, promethazine, propiomazine, propoxyphene, tramadol, zaleplone, zolpidem, and zopiclone. As proof of concept, hair from 29 authentic post mortem cases were analysed. The calibration range was established between 0.05ng/mg to 5.0ng/mg for all analytes except fentanyl (0.02-2.0), buprenorphine (0.04-2.0), and ketobemidone (0.05-4.0) as well as for alimemazine, amphetamine, cocaine, methadone, and promethazine (0.10-5.0). For all analytes, the accuracy of the fortified pooled hair matrix was 84-108% at the low level and 89-106% at the high level. The within series precisions were between 1.4 and 6.7% and the between series precisions were between 1.4 and 10.1%. From the 29 autopsy cases, 121 positive findings were encountered from 23 of the analytes in concentrations similar to those previously published. We conclude that the developed method proved precise and accurate and that it had sufficient performance for the purpose of detecting regular use of drugs or treatment with prescription drugs. To identify a compound we recommend the use of ion ratios as a complement to instrument software "matching scores".

Acrylfentanyl: Another new psychoactive drug with fatal consequences.

The European Nordic Countries are the most exposed to opioid-related deaths. Between April and October 2016, a series of forty lethal intoxications occurred in Sweden, in which the presence of the synthetic opioid acrylfentanyl was determined to be the main - or a contributing - cause of death. In the reported cases, the blood concentration of acrylfentanyl - mostly detected in combination with other drugs - ranged from 0.01ng/g to 5ng/g; victims were predominantly males (34 males and 6 females), and their age varied between 18 and 53 years. We further describe five cases, representative of the different drug administration route (nasal spray, tablets) and intentions (accidental or voluntary intoxication). Moreover, we address nine cases of non-lethal intoxication, in single (8 cases) or polydrug scenario (1 case). We discuss the present characteristics of the Swedish drug market for fentanyl-analogs in general and acrylfentanyl in particular, reporting a structural difficulty to effectively counteracting the appearance of unscheduled substances due to the constant turnover of new molecules on the recreational drug market.

In Vitro and In Vivo Metabolite Identification Studies for the New Synthetic Opioids Acetylfentanyl, Acrylfentanyl, Furanylfentanyl, and 4-Fluoro-Isobutyrylfentanyl.

New fentanyl analogs have recently emerged as new psychoactive substances and have caused numerous fatalities worldwide. To determine if the new analogs follow the same metabolic pathways elucidated for fentanyl and known fentanyl analogs, we performed in vitro and in vivo metabolite identification studies for acetylfentanyl, acrylfentanyl, 4-fluoro-isobutyrylfentanyl, and furanylfentanyl. All compounds were incubated at 10 µM with pooled human hepatocytes for up to 5 h. For each compound, four or five authentic human urine samples from autopsy cases with and without enzymatic hydrolysis were analyzed. Data acquisition was performed in data-dependent acquisition mode during liquid chromatography high-resolution mass spectrometry analyses. Data was analyzed (1) manually based on predicted biotransformations and (2) with MetaSense software using data-driven search algorithms. Acetylfentanyl, acrylfentanyl, and 4-fluoro-isobutyrylfentanyl were predominantly metabolized by N-dealkylation, cleaving off the phenethyl moiety, monohydroxylation at the ethyl linker and piperidine ring, as well as hydroxylation/methoxylation at the phenyl ring. In contrast, furanylfentanyl's major metabolites were generated by amide hydrolysis and dihydrodiol formation, while the nor-metabolite was minor or not detected in case samples at all. In general, in vitro results matched the in vivo findings well, showing identical biotransformations in each system. Phase II conjugation was observed, particularly for acetylfentanyl. Based on our results, we suggest the following specific and abundant metabolites as analytical targets in urine: a hydroxymethoxy and monohydroxylated metabolite for acetylfentanyl, a monohydroxy and dihydroxy metabolite for acrylfentanyl, two monohydroxy metabolites and a hydroxymethoxy metabolite for 4-fluoro-isobutyrylfentanyl, and a dihydrodiol metabolite and the amide hydrolysis metabolite for furanylfentanyl.

A non-fatal intoxication and seven deaths involving the dissociative drug 3-MeO-PCP.

INTRODUCTION: 3-methoxyphencyclidine (3-MeO-PCP) appeared on the illicit drug market in 2011 and is an analogue of phencyclidine, which exhibits anesthetic, analgesic and hallucinogenic properties. In this paper, we report data from a non-fatal intoxication and seven deaths involving 3-MeO-PCP in Sweden during the period March 2014 until June 2016. CASE DESCRIPTIONS: The non-fatal intoxication case, a 19-year-old male with drug problems and a medical history of depression, was found awake but tachycardic, hypertensive, tachypnoeic and catatonic at home. After being hospitalized, his condition worsened as he developed a fever and lactic acidosis concomitant with psychomotor agitation and hallucinations. After 22h of intensive care, the patient had made a complete recovery. During his hospitalization, a total of four blood samples were collected at different time points. The seven autopsy cases, six males and one female, were all in their twenties to thirties with psychiatric problems and/or an ongoing drug abuse. METHODS: 3-MeO-PCP was identified with liquid chromatography (LC)/time-of-flight technology and quantified using LC-tandem mass spectrometry. RESULTS: In the clinical case, the concentration of 3-MeO-PCP was 0.14µg/g at admission, 0.08µg/g 2.5h after admission, 0.06µg/g 5h after admission and 0.04µg/g 17h after admission. The half-life of 3-MeO-PCP was estimated to 11h. In the autopsy cases, femoral blood concentrations ranged from 0.05µg/g to 0.38µg/g. 3-MeO-PCP was the sole finding in the case with the highest concentration and the cause of death was established as intoxication with 3-MeO-PCP. In the remaining six autopsy cases, other medications and drugs of abuse were present as well. CONCLUSION: Despite being scheduled in January 2015, 3-MeO-PCP continues to be abused in Sweden. Exposure to 3-MeO-PCP may cause severe adverse events and even death, especially if the user does not receive life-supporting treatment.

Identifying Metabolites of Meclonazepam by High-Resolution Mass Spectrometry Using Human Liver Microsomes, Hepatocytes, a Mouse Model, and Authentic Urine Samples.

Meclonazepam is a benzodiazepine patented in 1977 to treat parasitic worms, which recently appeared as a designer benzodiazepine and drug of abuse. The aim of this study was to identify metabolites suitable as biomarkers of drug intake in urine using high-resolution mass spectrometry, authentic urine samples, and different model systems including human liver microsomes, cryopreserved hepatocytes, and a mice model. The main metabolites of meclonazepam found in human urine were amino-meclonazepam and acetamido-meclonazepam; also, minor peaks for meclonazepam were observed in three of four urine samples. These observations are consistent with meclonazepam having a metabolism similar to that of other nitro containing benzodiazepines such as clonazepam, flunitrazepam, and nitrazepam. Both metabolites were produced by the hepatocytes and in the mice model, but the human liver microsomes were only capable of producing minor amounts of the amino metabolite. However, under nitrogen, the amount of amino-meclonazepam produced increased 140 times. This study comprehensively elucidated meclonazepam metabolism and also illustrates that careful selection of in vitro model systems for drug metabolism is needed, always taking into account the expected metabolism of the tested drug.

Postmortem and Toxicological Findings in a Series of Furanylfentanyl-Related Deaths.

Over the course of 4 months in 2015 and 2016, a cluster of seven fatal intoxications involving the opioid-analogue furanylfentanyl occurred in Sweden; toxicological analysis showed presence of furanylfentanyl either as the only drug or in combination with other illicit substances. Previous publications have only reported non-lethal furanylfentanyl intoxications. In the cases presented here, furanylfentanyl intoxication-alone or in combination with other drugs-was determined to be the cause of death by the responsible pathologist. All victims were young (24-37 years old) males, five of which had a well-documented history of drug abuse. Femoral blood concentration of furanylfentanyl ranged from 0.41 ng/g to 2.47 ng/g blood. Five cases presented a complex panel of drugs of abuse and prescription drugs. Moreover, in five cases the concurrent presence of pregabalin corroborates previous observations indicating pregabalin as a possible contributing factor in polydrug intoxications. We conclude that it is difficult to establish a specific lethal concentration of furanylfentanyl, due to incompletely known effects of possible pharmacokinetic and pharmacodynamic interactions with other drugs, as well as to the unknown degree of tolerance to opioids. We suggest that a full toxicological screening-to assess the possibility of drug interactions-together with segmental hair analysis regarding opioids-to estimate the level of opioid tolerance-be carried out to assist in the interpretation of cases involving synthetic opioids such as furanylfentanyl.

Looking at flubromazolam metabolism from four different angles: Metabolite profiling in human liver microsomes, human hepatocytes, mice and authentic human urine samples with liquid chromatography high-resolution mass spectrometry.

Flubromazolam is a triazolam benzodiazepine that recently emerged as a new psychoactive substance. Since metabolism data are scarce and good analytical targets besides the parent are unknown, we investigated flubromazolam metabolism in vitro and in vivo. 10µmol/L flubromazolam was incubated with human liver microsomes for 1h and with cryopreserved human hepatocytes for 5h. Mice were administered 0.5 or 1.0mg flubromazolam/kg body weight intraperitoneally, urine was collected for 24h. All samples, together with six authentic forensic human case specimens, were analyzed (with or without hydrolysis, in case it was urine) by UHPLC-HRMS on an Acquity HSS T3 column with an Agilent 6550 QTOF. Data mining was performed manually and with MassMetasite software (Molecular Discovery). A total of nine metabolites were found, all generated by hydroxylation and/or glucuronidation. Besides O-glucuronidation, flubromazolam formed an N+-glucuronide. Flubromazolam was not metabolized extensively in vitro, as only two monohydroxy metabolites were detected in low intensity in hepatocytes. In the mice samples, seven metabolites were identified, which mostly matched the metabolites in the human samples. However, less flubromazolam N+-glucuronide and an additional hydroxy metabolite were observed. The six human urine specimens showed different extent of metabolism: some samples had an intense flubromazolam peak next to a minute signal for a monohydroxy metabolite, others showed the whole variety of hydroxylated and glucuronidated metabolites. Overall, the most abundant metabolite was a monohydroxy metabolite, which we propose as α-hydroxyflubromazolam based on MSMS fragmentation. These metabolism data will assist in interpretation and analytical method development.

25C-NBOMe and 25I-NBOMe metabolite studies in human hepatocytes, in vivo mouse and human urine with high-resolution mass spectrometry.

25C-NBOMe and 25I-NBOMe are potent hallucinogenic drugs that recently emerged as new psychoactive substances. To date, a few metabolism studies were conducted for 25I-NBOMe, whereas 25C-NBOMe metabolism data are scarce. Therefore, we investigated the metabolic profile of these compounds in human hepatocytes, an in vivo mouse model and authentic human urine samples from forensic cases. Cryopreserved human hepatocytes were incubated for 3 h with 10 µM 25C-NBOMe and 25I-NBOMe; samples were analyzed by liquid chromatography high-resolution mass spectrometry (LC-HRMS) on an Accucore C18 column with a Thermo QExactive; data analysis was performed with Compound Discoverer software (Thermo Scientific). Mice were administered 1.0 mg drug/kg body weight intraperitoneally, urine was collected for 24 h and analyzed (with or without hydrolysis) by LC-HRMS on an Acquity HSS T3 column with an Agilent 6550 QTOF; data were analyzed manually and with WebMetabase software (Molecular Discovery). Human urine samples were analyzed similarly. In vitro and in vivo results matched well. 25C-NBOMe and 25I-NBOMe were predominantly metabolized by O-demethylation, followed by O-di-demethylation and hydroxylation. All methoxy groups could be demethylated; hydroxylation preferably occurred at the NBOMe ring. Phase I metabolites were extensively conjugated in human urine with glucuronic acid and sulfate. Based on these data and a comparison with synthesized reference standards for potential metabolites, specific and abundant 25C-NBOMe urine targets are 5'-desmethyl 25C-NBOMe, 25C-NBOMe and 5-hydroxy 25C-NBOMe, and for 25I-NBOMe 2' and 5'-desmethyl 25I-NBOMe and hydroxy 25I-NBOMe. These data will help clinical and forensic laboratories to develop analytical methods and to interpret results. Copyright © 2016 John Wiley & Sons, Ltd.

LC-QTOF-MS as a superior strategy to immunoassay for the comprehensive analysis of synthetic cannabinoids in urine.

The objective of this study was to compare the performance of an immunoassay screening for synthetic cannabinoids with a newly developed confirmation method using liquid chromatography quadrupole time-of-flight mass spectrometry. The screening included metabolites from JWH-018, JWH-073, and AM-2201. The confirmation included metabolites from AM-2201, JWH-018, JWH-019, JWH-073, JWH-081, JWH-122, JWH-210, JWH-250, JWH-398, MAM-2201, RCS-4, and UR-144. The immunoassay was tested and found to have no cross-reactivity with UR-144 metabolites but considerable cross-reactivity with MAM-2201 and JWH-122 metabolites. Sensitivity and specificity for the immunoassay were evaluated with 87 authentic urine samples and found to be 87% and 82%, respectively. With a cutoff at 2 ng/ml, the confirmation showed 80 positive findings in 38 cases. The most common finding was JWH-122 5-OH-pentyl, followed by JWH-018 5-OH-pentyl. There were 9 findings of UR-144 metabolites and 3 of JWH-073 metabolites. In summary, the immunoassay performed well, presenting both high sensitivity and specificity for the synthetic cannabinoids present in the urine samples tested. The rapid exchange of one cannabinoid for another may pose problems for immunoassays as well as for confirmation methods. However, we consider time-of-flight mass spectrometry to be superior since new metabolites can be quickly included and identified.

Toxicological findings of synthetic cannabinoids in recreational users.

In recent years, several synthetic cannabinoid compounds have become popular recreational drugs of abuse because of their psychoactive properties. This paper presents toxicological findings of synthetic cannabinoids in whole blood from some cases of severe intoxication including quantitative data from recreational users and a fatal intoxication. Samples were analyzed by liquid chromatography-tandem mass spectrometry in a scheduled multiple reaction mode after a basic liquid extraction. Twenty-nine synthetic cannabinoids were included in the method. In our data set of ~3000 cases, 28% were found positive for one or more synthetic cannabinoid(s). The most common finding was AM-2201. Most of the analytes had median concentrations of <0.5 ng/g in agreement with other published data. The emerging drugs MAM-2201 (n = 151) and UR-144 (n = 181) had mean (median) concentrations of 1.04 (0.37) and 1.26 (0.34), respectively. The toxicity of the synthetic cannabinoids seems to be worse than that of natural cannabis, probably owing to the higher potency and perhaps also to the presence of several different cannabinoids in the smoked incense and the difficulties of proper dosing. The acute toxic effects may under certain circumstances contribute to death.

A cluster of deaths involving 5-(2-aminopropyl)indole (5-IT).

During 2012, the designer drug 5-(2-aminopropyl)indole emerged in Sweden, and became available at different web sites under the name 5-IT or 5-API. This compound is an indole derivative and a positional isomer of alpha-methyltryptamine. In this paper, we report the pathology and toxicology from 15 deaths involving 5-IT. Routine postmortem toxicology was performed in femoral blood, using a targeted screening for pharmaceuticals and drugs of abuse with liquid chromatography time-of-flight technology, and positive results were quantified using chromatographic techniques. For 5-IT, a new method was developed using ultra-high-performance liquid chromatography and tandem mass spectrometry. In 11 cases, intoxication was the cause of death. Two cases were signed out as causa ignota, and they were considered to be natural deaths. All determinations of 5-IT were performed in femoral blood and the concentrations ranged from 0.7 to 18.6 µg/g. Two cases had 5-IT as the only drug identified, while the others presented with other psychotropic drugs or medications in the blood as well. Shortly after this series of deaths, 5-IT was scheduled as a hazardous substance according to the regulation Certain Goods Dangerous to Health on 18 September 2012 prohibiting the handling and selling of the drug. Since then, no positive cases have been found.

A screening method for 30 drugs in hair using ultrahigh-performance liquid chromatography time-of-flight mass spectrometry.

OBJECTIVES: The objectives of this study were to develop and to validate a qualitative screening method that met the new Society of Hair Testing (SoHT) guideline criteria for thresholds. METHODS: Extraction of 20 mg hair was performed by a previously validated procedure using overnight incubation in a mixture of methanol:acetonitrile:formiate buffer pH 3 (10:10:80). Analysis was performed on an Agilent 6540 quadrupole time-of-flight mass spectrometer in combination with an Agilent 1290 Infinity ultrahigh-performance liquid chromatography system. Separation was achieved with a 12-minute linear gradient chromatography on a high-strength silica T3 column at acidic conditions. An in-house database containing 30 compounds from the groups amphetamines, opiates, opioids, cocaine, benzodiazepines, and other sedatives including 6 deuterated internal standards was built by analyzing solutions from certified standards. Data were extracted using mass accuracy of ± 10 ppm, retention time deviation of ± 0.15 minutes, and area of ≥ 30,000 counts. Identification was based on scoring of retention time, accurate mass measurement, and isotopic pattern. Validation included selectivity, repeatability of analyte area, and the scoring parameters at the proposed thresholds and a method comparison with the present liquid chromatography-mass spectrometry-mass spectrometry method using 50 authentic hair samples. A daily cutoff calibrator was used to identify positive samples. RESULTS: All cutoffs could be met with imprecisions of less than 5% for most parameters and analytes. Hair from drug-free subjects did not produce any positive results and the method comparison agreed in more than 90% of the cases. CONCLUSIONS: We conclude that the developed method meets the criteria of the new SoHT guidelines for screening cutoffs. Even though no thresholds have been suggested for benzodiazepines, we conclude that thresholds between 0.05 and 0.1 ng/mg should be sufficient to determine regular use of these substances.

Liquid chromatography/time-of-flight mass spectrometry analysis of postmortem blood samples for targeted toxicological screening.

A liquid chromatography/time-of-flight mass spectrometry (LC-TOF-MS) method for targeted toxicological screening in human postmortem blood samples from forensic autopsy cases has been developed, validated and compared with a previously used method using gas chromatography with nitrogen-phosphorus detection (GC-NPD). Separation was achieved within 12 min by high-resolution gradient chromatography. Ions were generated in positive and negative electrospray ionization mode and were detected in 2-GHz single mass spectrometry mode, m/z range 50-1,000. Before injection, 0.25 g blood was prepared by protein precipitation with 500 µL of a mixture of acetonitrile and ethanol containing deuterated internal standards. An in-house database comprising 240 drugs and metabolites was built by analysing solutions from certified standards or other documented reference material available. Identification was based on scoring of retention time, accurate mass measurement and isotopic pattern. Validation was performed on spiked blood samples and authentic postmortem blood samples. The thresholds defined as minimum required performance levels were for most compounds in the range from 0.01 to 0.10 µg/g. Typically, a mass error of less than 2 ppm and a precision of area measurements of less than 5 % coefficient of variation were achieved. Positive identification was confirmed at concentrations up to 500 µg/g. Most compounds were determined in positive ionization mode, but for a limited number of compounds (fewer than 4 %) negative ionization was needed and a few early-eluted compounds could not be identified owing to substantial influence of interferences from the matrix and were thus not included in the screening. A robust and valid toxicological screening by LC-TOF-MS for postmortem blood samples, covering 50 % more compounds, and with higher precision and sensitivity than the previously used screening by GC-NPD was achieved.

Unintentional fatal intoxications with mitragynine and O-desmethyltramadol from the herbal blend Krypton.

The leaves of Kratom, a medicinal plant in Southeast Asia, have been used as an herbal drug for a long time. At least one of the alkaloids present in Kratom, mitragynine, is a mu-receptor agonist. Both Kratom and an additional preparation called Krypton are available via the internet. It seems to consist of powdered Kratom leaves with another mu-receptor agonist, O-desmethyltramadol, added. O-Desmethyltramadol is an active metabolite of tramadol, a commonly prescribed analgesic. We present nine cases of intoxication, occurring in a period of less than one year, where both mitragynine and O-desmethyltramadol were detected in the postmortem blood samples. Neither tramadol nor N-desmethyltramadol was present in these samples, which implies that the ingested drug was O-desmethyltramadol. The blood concentrations of mitragynine, determined by ultra-performance liquid chromatography-tandem mass spectrometry, ranged from 0.02 to 0.18 µg/g, and O-desmethyltramadol concentrations, determined by gas chromatography with nitrogen-specific detection, ranged from 0.4 to 4.3 µg/g. We believe that the addition of the potent mu-receptor agonist O-desmethyltramadol to powdered leaves from Kratom contributed to the unintentional death of the nine cases presented and conclude that intake of Krypton is not as harmless as it often is described on internet websites.

LC-MS-MS analysis of buprenorphine and norbuprenorphine in whole blood from suspected drug users.

A liquid chromatography tandem mass spectrometry method is described for the analysis of buprenorphine and norbuprenorphine in whole blood. Linearity was achieved between 0.2-5 ng/g for buprenorphine and 0.5-5 ng/g for norbuprenorphine. Stability studies on spiked whole blood and an authentic sample showed no degradation of buprenorphine- and norbuprenorphine-glucuronide to their respective aglycones. Buprenorphine and norbuprenorphine showed some degradation when stored at 4°C for three weeks, but was stable when stored at -20°C for 4 weeks. The method was applied to forensic cases of driving under the influence of drugs (DUID) and petty drug offences (PDO) during 2007-2009. Out of 2459 cases analyzed, 322 were positive for both buprenorphine and norbuprenorphine (13%), 219 for buprenorphine only (9%), and 12 for norbuprenorphine only (0.5%). The mean and median concentrations (N=322) were 1.7 and 1.0 ng/g, respectively, for buprenorphine and norbuprenorphine. The mean and median norbuprenorphine/buprenorphine ratios were 1.5 and 1.1, respectively. There was no significant difference in concentration ratios for DUID and PDO cases (p>0.05). We conclude that the described method for analysis of buprenorphine and norbuprenorphine in whole blood could be used to investigate use or misuse of buprenorphine but that many of the cases presented with very low concentrations of buprenorphine. We also conclude that analysis should be performed within two weeks unless samples are stored frozen prior to analysis.

Liquid chromatography/tandem mass spectrometry method for determination of olanzapine and N-desmethylolanzapine in human serum and cerebrospinal fluid.

A validated, accurate and sensitive LC-MS/MS method for determination of olanzapine and its metabolite N-desmethylolanzapine has been developed. The analytes were quantified by tandem mass spectrometry operating in positive electrospray ionization mode with multiple reaction monitoring. Olanzapine and desmethylolanzapine were extracted from serum or cerebral spinal fluid samples, 200 microl, with tert-butyl methyl ether using olanzapine-D3 as internal standard. Calibrations for olanzapine and desmethylolanzapine were linear within the selected range of 0.2-30 ng/ml (6-96 nM) in cerebral spinal fluid and for olanzapine in plasma, in the range of 5-100 ng/ml (16-320 nM). The method was successfully used for the analysis of samples from patients treated with olanzapine in the dose range of 2.5-25mg/day.

Urinary detection times and excretion patterns of flunitrazepam and its metabolites after a single oral dose.

We investigated the excretion profiles of flunitrazepam metabolites in urine after a single dose. Sixteen volunteers received either 0.5 or 2.0 mg flunitrazepam. Urine samples were collected after 2, 4, 6, 8, 12, 24, 48, 72, 96, 120, 240, and 336 h. Samples were screened using CEDIA (300 microg/L cutoff) and quantitated using liquid chromatography-tandem mass spectrometry. The cutoff was 0.5 microg/L for flunitrazepam, N-desmethylflunitrazepam, 7-aminoflunitrazepam, 7-aminodesmethylflunitrazepam, 7-acetamidoflunitrazepam, and 7-acetamidodesmethylflunitrazepam. None of the subjects receiving 0.5 mg were screened positive, and only 23 of 102 samples from the subjects given 2.0 mg were positive with CEDIA. The predominant metabolites were 7-aminoflunitrazepam and 7-aminodesmethylflunitrazepam. For all subjects given the low dose, 7-aminoflunitrazepam was detected up to 120 h, and for two subjects for more than 240 h. Seven subjects given the high dose were positive up to 240 h for 7-aminoflunitrazepam. We conclude that the ratio 7-aminodesmethylflunitrazepam to 7-aminoflunitrazepam increased with time, independent of dose, and may be used to estimate the time of intake. For some low-dose subjects, the metabolite concentrations in the early samples were low and a chromatographic method may fail to detect the intake. We think laboratories should consider this when advising police and hospitals about sampling as well as when they set up strategies for analysis.

Connectivity of neutral networks, overdispersion, and structural conservation in protein evolution.

Protein structures are much more conserved than sequences during evolution. Based on this observation, we investigate the consequences of structural conservation on protein evolution. We study seven of the most studied protein folds, determining that an extended neutral network in sequence space is associated with each of them. Within our model, neutral evolution leads to a non-Poissonian substitution process, due to the broad distribution of connectivities in neutral networks. The observation that the substitution process has non-Poissonian statistics has been used to argue against the original Kimura neutral theory, while our model shows that this is a generic property of neutral evolution with structural conservation. Our model also predicts that the substitution rate can strongly fluctuate from one branch to another of the evolutionary tree. The average sequence similarity within a neutral network is close to the threshold of randomness, as observed for families of sequences sharing the same fold. Nevertheless, some positions are more difficult to mutate than others. We compare such structurally conserved positions to positions conserved in protein evolution, suggesting that our model can be a valuable tool to distinguish structural from functional conservation in databases of protein families. These results indicate that a synergy between database analysis and structurally based computational studies can increase our understanding of protein evolution.