Development and validation of a sensitive LC-MS-MS method to quantify psilocin in authentic oral fluid samples

Psilocin is an active substance and a dephosphorylated product of psilocybin formed after the ingestion of mushrooms. The low stability caused by the quick oxidation of this analyte requires sensitive methods for its determination in biological matrices. In this work, we described the development, optimization and validation of a method for the quantification of psilocin in authentic oral fluid samples by liquid chromatography-tandem mass spectrometry. Liquid-liquid extraction was performed using 100 µL of oral fluid samples collected with a Quantisal™ device and t-butyl methyl ether as the extraction solvent. The method showed acceptable performance, with limits of detection and quantification of 0.05 ng/mL, and the calibration model was achieved between 0.05 and 10 ng/mL. Bias and imprecision results were below -14.2% and 10.7%, respectively. Ionization suppression/enhancement was lower than -30.5%, and recovery was >54.5%. Dilution integrity bias was <14.4%. No endogenous and exogenous interferences were observed upon analyzing oral fluid from 10 different sources and 56 pharmaceuticals and drugs of abuse, respectively. No carryover was observed at 10 ng/mL. Psilocin was stable in oral fluid at -20°C, 4°C and 24°C up to 24, 72 and 24 h, respectively, with variations <17.7%. The analyte was not stable after three freeze/thaw cycles, with variations between -73% and -60%. This suggests the instability of psilocin in oral fluid samples, which requires timely analysis, as soon as possible after the collection. The analyte remained stable in processed samples in an autosampler (at 10°C) for up to 18 h. The method was successfully applied for the quantification of five authentic samples collected from volunteers attending parties and electronic music festivals. Psilocin concentrations ranged from 0.08 to 36.4 ng/mL. This is the first work to report psilocin concentrations in authentic oral fluid samples.

Comparing presumptive with direct-to-definitive drug testing in oral fluid vs. urine for a U.S. national sample of individuals misusing drugs

BACKGROUND

The aims are to compare the results of presumptive drug testing with confirmation of positives vs. direct-to-definitive drug testing, combined with investigation of urine vs. oral fluid as test matrices.

METHODS

Paired oral fluid and urine specimens were collected voluntarily and anonymously from 1098 individuals applying for methadone treatment in 11 clinics across 7 U.S. states. All specimens were analyzed by immunoassay (IA) and liquid chromatography-tandem mass spectrometry (LC-MS-MS).

RESULTS

Confirmed IA prevalences for urine were significantly higher than for oral fluid for 7 out of 10 drug classes - benzodiazepines, cannabis, cocaine, methadone, opiates, oxycodone and tramadol. Drug prevalences by direct-to-definitive LC-MS-MS were either the same or higher than prevalences by confirmed IA. Drug prevalences by LC-MS-MS were higher in urine for two drug classes (cocaine, methadone) and higher in oral fluid for two drug classes (buprenorphine, tramadol), but were equivalent in urine and oral fluid when averaged over all 10 drug classes. Certain drugs of special concern such as heroin and buprenorphine were more frequently detected in oral fluid than urine.

CONCLUSIONS

Urine analysis showed some technical advantage over oral fluid in sensitivity to several drug classes within a confirmed IA testing protocol, but this may be outweighed if there is reason to believe that tampering with urine specimens is a significant problem. Overall drug detection by direct-to-definitive testing was similar for oral fluid and urine, but one matrix may be preferable if there is a particular drug of clinical or epidemiological interest.

Discriminating cocaine use from other sympathomimetics using wearable electrocardiographic (ECG) sensors

BACKGROUND

Our group has established the feasibility of using on-body electrocardiographic (ECG) sensors to detect cocaine use in the human laboratory. The purpose of the current study was to test whether ECG sensors and features are capable of discriminating cocaine use from other non-cocaine sympathomimetics.

METHODS

Eleven subjects with cocaine use disorder wore the Zephyr BioHarness™ 3 chest band under six experimental (drug and non-drug) conditions, including 1) laboratory, intravenous cocaine self-administration, 2) after a single oral dose of methylphenidate, 3) during aerobic exercise, 4) during tobacco use (N=7 who smoked tobacco), and 5) during routine activities of daily inpatient living (unit activity). Three ECG-derived feature sets served as primary outcome measures, including 1) the RR interval (i.e., heart rate), 2) a group of ECG interval proxies (i.e., PR, QS, QT and QTc intervals), and 3) the full ECG waveform. Discriminatory power between cocaine and non-cocaine conditions for each of the three outcomes measures was expressed as the area under the receiver operating characteristics (AUROC) curve.

RESULTS

All three outcomes successfully discriminated cocaine use from unit activity, exercise, tobacco, and methylphenidate conditions with a mean AUROC values ranging from 0.66 to 0.99 and with least squares means values all statistically different/higher than 0.5 among all subjects [F(3, 99) = 3.38, p =0.02] and among those with tobacco use [F(4, 84) = 5.39, p = 0.0007].

CONCLUSIONS

These preliminary results support discriminatory power of wearable ECG sensors for detecting cocaine use.

A Non-Invasive Method for Detection of Antihypertensive Drugs in Biological Fluids: The Salivary Therapeutic Drug Monitoring

Objectives: Arterial hypertension is still the most frequent cause of cardiovascular and cerebrovascular morbidity and mortality. Antihypertensive treatment has proved effective in reduction of cardiovascular risk. Nevertheless, lifestyle interventions and pharmacological therapy in some cases are ineffective in reaching blood pressure target values, despite full dose and poly-pharmacological treatment. Poor adherence to medications is an important cause of treatment failure. Different methods to assess therapeutic adherence are currently available: Therapeutic drug monitoring in biological fluids has previously demonstrated its efficacy and reliability. Plasma and urine have been already used for this purpose, but they may be affected by some practical limitations. Saliva may represent a feasible alternative.

Methods: Fourteen antihypertensive drugs and two metabolites were simultaneously tested in plasma, urine, and saliva. Tested molecules included: atenolol, nebivolol, clonidine, ramipril, olmesartan, telmisartan, valsartan, amlodipine, nifedipine, doxazosin, chlorthalidone, hydrochlorothiazide, indapamide, sacubitril, ramiprilat, and sacubitrilat. Therapeutic drug monitoring was performed using ultra-high performance liquid chromatography, coupled to tandem mass spectrometry (UHPLC-MS/MS). The method has been preliminarily evaluated in a cohort of hypertensive patients.

Results: The method has been validated according to US Food and Drug Administration (FDA) and European Medicines Agency (EMA) guidelines. The application on a cohort of 32 hypertensive patients has demonstrated sensibility and specificity of 98% and 98.1%, respectively, with a good feasibility in real-life clinical practice.

Conclusion: Saliva may represent a feasible biological sample for therapeutic drug monitoring by non-invasive collection, prompt availability, and potential accessibility also in out-of-clinic settings.

Comparison of different chiral selectors for the enantiomeric determination of amphetamine-type substances in human urine by solid-phase extraction followed by capillary electrophoresis-tandem mass spectrometry

The present study develops a method for the enantioseparation of a group of amphetamines and their metabolites in urine by CE coupled to MS/MS (CE-MS/MS). Amphetamines present a chiral center and thus two enantiomers, which is important from a toxicological point of view because they may have different pharmacokinetic and pharmacological properties. It is therefore essential to find suitable methods to distinguish both enantiomers. Today the use of CE is becoming more important in this field since, with the simple addition of a chiral selector to the background electrolyte, the enantioseparation can easily be achieved. However, when CE is coupled to MS, the use of volatile chiral selectors and compatible background electrolytes or other strategies such as the countercurrent migration approach are required to avoid contamination of the ion source from nonvolatile species. In the present study, we use the latter strategy to evaluate six different chiral selectors using CE-MS/MS. As a sample pre-treatment, two cationic-exchange sorbents-Oasis WCX and Oasis MCX-are compared for the urine pre-treatment. Using this method, it was possible to achieve the complete chiral separation of the amphetamines under study with detection limits ranging between 0.8 and 1.5 ng/mL and method quantification limits between 2.0 and 8.0 ng/mL. Matrix-matched calibration curves up to 150 ng/mL were used to cover the usual concentration ranges at which amphetamines have generally been found in toxicological and forensic analyses.

A Fast Analytical Method for Determining Synthetic Cathinones in Oral Fluid by Liquid Chromatography-Tandem Mass Spectrometry

In this paper, we present a method for simultaneously determining 11 synthetic cathinones in oral fluid (OF) by liquid chromatography-tandem mass spectrometry. Synthetic cathinones, a wide variety of which are available on the market, are constantly evolving. It is therefore important to provide efficient methods for determining cathinones in different matrices. A common matrix for detecting recent drug intake is OF, which can easily be collected using one of numerous commercial devices. Most methods aimed at determining drugs in biological samples such as OF require labor-intensive and time-consuming sample-preparation steps. However, the pretreatment of complex samples is often a challenge in the development of a method. For this reason, in this paper, we present a simple, easy-to-handle alternative that uses a Salivette® device and pretreats the sample in the same device. Matrix-matched calibration curves were used to cover the concentration range at which these substances are usually present in the OF from drug consumers. The method detection limits ranged from 0.003 to 0.03 ng/g, and the method quantification limits were set at 0.075 ng/g. This is a simple, rapid and sensitive method with good potential for determining recent drug consumption in OF.

Determination of Synthetic Cathinones in Urine and Oral Fluid by Liquid Chromatography High-Resolution Mass Spectrometry and Low-Resolution Mass Spectrometry: A Method Comparison

Synthetic cathinones have become very popular recreational drugs. Therefore, determining them in biological samples is now a matter of concern. In recent years, different methods that have been developed can determine these drugs at low-concentration levels. In general, liquid chromatography mass spectrometry detection plays an important role in these methods and the trend is to use low-resolution and high-resolution mass spectrometry. In this article, for the first time, we compare these two analyzers using an Orbitrap and a triple quadrupole mass spectrometer in order to determine a group of synthetic cathinones in urine and oral fluid samples. For this comparison, we evaluated and compared different parameters: Method detection and quantification limits, linearity, apparent recoveries, matrix effect, repeatability (intra-day), reproducibility (inter-day), and accuracy. Similar results were obtained for the two analyzers for the apparent recoveries and matrix effect. However, triple quadrupole showed higher sensitivity compared to Orbitrap for both urine and oral fluid samples. The quantification limits in urine and the detection limits in saliva were two times lower for triple quadrupole. Finally, when blind samples were analyzed to study the accuracy, similar results were obtained for both analyzers.

What the lab can and cannot do: clinical interpretation of drug testing results

Urine drug testing is one of the objective tools available to assess adherence. To monitor adherence, quantitative urinary results can assist in differentiating "new" drug use from "previous" (historical) drug use. "Spikes" in urinary concentration can assist in identifying patterns of drug use. Coupled chromatographic-mass spectrometric methods are capable of identifying very small amounts of analyte and can make clinical interpretation rather challenging, specifically for drugs that have a longer half-life. Polypharmacy is common in treatment and rehabilitation programs because of co-morbidities. Medications prescribed for comorbidities can cause drug-drug interaction and phenoconversion of genotypic extensive metabolizers into phenotypic poor metabolizers of the treatment drug. This can have significant impact on both pharmacokinetic (PK) and pharmacodynamic properties of the treatment drug. Therapeutic drug monitoring (TDM) coupled with PKs can assist in interpreting the effects of phenoconversion. TDM-PKs reflects the cumulative effects of pathophysiological changes in the patient as well as drug-drug interactions and should be considered for treatment medications/drugs used to manage pain and treat substance abuse. Since only a few enzyme immunoassays for TDM are available, this is a unique opportunity for clinical laboratory scientists to develop TDM-PK protocols that can have a significant impact on patient care and personalized medicine. Interpretation of drug screening results should be done with caution while considering pharmacological properties and the presence or absence of the parent drug and its metabolites. The objective of this manuscript is to review and address the variables that influence interpretation of different drugs analyzed from a rehabilitation and treatment programs perspective.

The Path to Perfect Pediatric Posology - Drug Development in Pediatrics

Reluctance to enroll pediatric subjects in clinical trials has left gaps in information about dosing, safety, and efficacy of medications. Pharmacotherapeutic information for pediatric patients may be available for only a small range of ages and may be deficient, as children respond differently as they grow and mature from prematurity to adolescence. Current regulations, however, require early planning for the participation of children in drug development, as pediatric plans must be submitted at the end of phase 1 (European Union) or the end of phase 2 (United States). These plans are extensive, outlining planned studies, subjects to be enrolled, dose and dosage form justification, planned observations, and statistical analysis as well as planned modeling, simulation, and extrapolation analyses. The extent to which efficacy information in adults can be extrapolated to children depends on how similar the disease is in adults and each of the 5 pediatric age groups. Extrapolation may not be possible for conditions that do not occur in adults, requiring a complete development plan in adults, or extrapolation may be complete because of similar pathology and response to treatment. Pharmacokinetic and safety information cannot be extrapolated and must be collected in children of all ages, unless a waiver is granted. Physiologically based pharmacokinetic modeling, optimal design, population pharmacokinetics, and scavenged samples are all examples of new methodologies being used to study pediatric therapeutics. Clinicaltrials.gov and EU Clinical Trials registry are good sources of results of pediatric trials, although sponsors are also working toward prompt publication of study results in peer-reviewed journals.

Hair Analysis: Contamination versus Incorporation from the Circulatory System-Investigations on Single Hair Samples Using Time-of-Flight Secondary Ion Mass Spectrometry and Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry

Contamination is a highly controversial issue in hair analysis. Therefore, hair testing protocols typically include wash steps to remove contamination. However, recent studies claim that washing could also lead to permanent incorporation of contaminants into hair, thus questioning the validity of hair testing at all. In the present study, matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) with longitudinal sectioning of single hairs and different decontamination protocols was used to reveal differences between the incorporation of a substance into hair from external sources and an incorporation via bloodstream. Single hairs were longitudinally sectioned using a custom-made sample holder. Data were acquired with MALDI-MS by rastering each hair individually. Single hair samples from drug users, blank hairs, and zolpidem- and zolpidem-D6-soaked hairs were investigated. Different published washing protocols were tested, and an in-house washing protocol was developed. For images with higher spatial resolution, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used. Longitudinal sectioning of hairs dramatically increased sensitivity; even single-dose administrations of zolpidem in single hairs could thus be detected using MALDI-MS. Zolpidem from external sources could be detected in large quantities in superficial hair structures. Zolpidem from consumer hairs, proposed to be strongly bound to inner hair structures, could not be completely removed even by the strongest tested decontamination protocol, whereas zolpidem-soaked hairs could be cleared almost completely with the developed in-house wash protocol. The applied methods allowed a first insight into the connection of decontamination protocols and wash-in phenomena in hair analysis. Further studies with other drugs are necessary to assess the general validity of these findings.

The Dangerous Pattern of Concurrent Use of Alcohol and Cocaine Among Drunk-Drivers of Northeast Italy

Aim

To estimate the prevalence of drug and polydrug use among drunk-drivers during the driving license regranting program, in order to assess the inclusion of toxicological tests on hair and urine samples in the systematic methodology in this category of subjects.

Short summary

A total of 2160 drunk-drivers were tested for alcohol and drugs during driving license regranting. Thirty-one subjects showed alcohol use, 212 illicit drug use and, among these, 131 were polydrug users. Nineteen different patterns of drug and polydrug use were found. Cocaine was detected in 165 subjects.

Methods

The study was performed on 2160 drunk-drivers examined at Legal Medicine and Toxicology Unit of the University of Padova, in a 3-year-period (2014-2017). The positivity for one or more illicit drugs in hair or urine samples was confirmed by LC/MS and GC/MS methods. Chi-square test, Fischer's exact test and Cochran-Armitage Trend test were used to study the correlation between general characteristics of the examined sample and the presence of drug/polydrug use.

Results

Thirty-one subjects showed alcohol use, 212 illicit drug use and, among these, 131 were polydrug users. Nineteen different patterns of drug and polydrug use were found. Cocaine was detected in 165 subjects in whom 122 showed a concurrent use of alcohol and cocaine, identified through the detection of cocaethylene in hair samples. No significant association and/or trends between drug/polydrug use and the general characteristics of the sample were detected.

Conclusions

The results show that drug and polydrug use among drunk-drivers should be subjected to toxicological as well as alcohological monitoring, especially in the regranting procedure. The implementation of this procedure could improve the knowledge of dimensions of the issue, providing a powerful means for the reduction of phenomenon of driving under the influence of alcohol and drugs.

Combining ecological momentary assessment with objective, ambulatory measures of behavior and physiology in substance-use research

Whereas substance-use researchers have long combined self-report with objective measures of behavior and physiology inside the laboratory, developments in mobile/wearable electronic technology are increasingly allowing for the collection of both subjective and objective information in participants' daily lives. For self-report, ecological momentary assessment (EMA), as implemented on contemporary smartphones or personal digital assistants, can provide researchers with near-real-time information on participants' behavior and mood in their natural environments. Data from portable/wearable electronic sensors measuring participants' internal and external environments can be combined with EMA (e.g., by timestamps recorded on questionnaires) to provide objective information useful in determining the momentary context of behavior and mood and/or validating participants' self-reports. Here, we review three objective ambulatory monitoring techniques that have been combined with EMA, with a focus on detecting drug use and/or measuring the behavioral or physiological correlates of mental events (i.e., emotions, cognitions): (1) collection and processing of biological samples in the field to measure drug use or participants' physiological activity (e.g., hypothalamic-pituitary-adrenal axis activity); (2) global positioning system (GPS) location information to link environmental characteristics (disorder/disadvantage, retail drug outlets) to drug use and affect; (3) ambulatory electronic physiological monitoring (e.g., electrocardiography) to detect drug use and mental events, as advances in machine learning algorithms make it possible to distinguish target changes from confounds (e.g., physical activity). Finally, we consider several other mobile/wearable technologies that hold promise to be combined with EMA, as well as potential challenges faced by researchers working with multiple mobile/wearable technologies simultaneously in the field.

Driving under the influence of cocaine: Quantitative determination of basic drugs in oral fluid obtained during roadside controls and a controlled study with cocaine users

Using the Belgian Drugs and Driving procedure, 36% of the cocaine-positive oral fluid (OF) screening results were not confirmed in plasma. This study investigates the impact of the choice of screening devices and confirmation matrix on the detection of cocaine use. An ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method quantifying cocaine, benzoylecgonine (BZE), and other basic drugs in OF was developed and validated. This method monitored OF samples obtained either from a roadside (n = 12) or a double-blind controlled study with cocaine users (n = 10) who were given either a capsule containing 300 mg of cocaine-HCl or a placebo. The OF data were compared to plasma concentrations to obtain concentration-time profiles. In addition, the sensitivity and accuracy of the Drugwipe5S® was assessed. A significant difference between the OF volume collected at baseline/placebo (median 0.93 mL [range 0.43-1.92 mL]) or after cocaine-HCL intake (0.79 mL [0.30-1.21 mL]) was observed. The median OF/Plasma at the 3 collection time points were 10.7, 13.8, 6.7 for cocaine and 0.8, 1.7, 0.8 for BZE, respectively. The Drugwipe5S® detected cocaine use until at least 4 hours after intake. When applying the Belgian legal confirmation decision limit of 10 ng/mL in OF, an accuracy of 75%-98% was observed, depending on the study setting. Cocaine concentrations in OF were much higher and were detected longer as compared to plasma, when applying the same decision limit. From a toxicological viewpoint, the longer detection window with the higher sensitivity of Cocaine and BZE is beneficial to detect drivers in the crash/fatigue phase.

Keratinous matrices for the assessment of drugs of abuse consumption: A correlation study between hair and nails

Keratinous matrices - hair and nails - accumulate substances over time and allow retrospective investigation of past consumption. Analysis of these matrices can provide information complementary to blood and urine analysis or can be used as standalone. So far, research has primarily focused on the detection of substances in hair, while studies in nails are scarce. In this study, we assessed concentrations of drugs of abuse and their metabolites in hair, fingernails, and toenails collected from the same individuals to evaluate differences and correlations between matrices. A total of 26 hair, 24 fingernail, and 18 toenail samples were collected. Samples were analysed by a validated liquid chromatography-tandem mass spectrometry method able to simultaneously detect the following compounds: amphetamine (AMP), methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyethylamphetamine, morphine (MOR), codeine (COD), 6-monoacetylmorphine (6-MAM), methadone (MTD), 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), cocaine (COC), benzoylecgonine (BE), and ecgonine methyl ester (EME). Strong positive correlations between hair, fingernails, and toenails were present for COC, BE, EME, AMP and MDMA. MOR, COD, 6-MAM, MTD and EDDP showed positive trends. Concentrations were generally higher in nails compared to hair. Ratios between parent compounds and their metabolites were assessed for 6-MAM/MOR, EDDP/MTD, BE/COC and EME/COC. Preliminary cut-off concentrations for COC, BE, EME and AMP in fingernails and toenails were proposed. In light of these results, nails can be considered as a useful alternative to hair for monitoring of long-term drug consumption. However, care should be taken regarding the variability in the accumulation of compounds between the matrices.

Identification and quantitation of phosphatidylethanols in oral fluid by liquid chromatography-tandem mass spectrometry

BACKGROUND

Phosphatidylethanols (PEth) are formed from phosphatidylcholines and ethanol and are used as a specific and sensitive alcohol biomarker. An analytical method for analysis of PEth in oral fluid based on high-performance liquid chromatography coupled to a quadrupole tandem mass spectrometer (LC-MS/MS) was developed and validated and applied on samples collected from patients undergoing alcohol detoxification.

METHODS

A 200-μL aliquot of oral fluid, collected using the QuantisalTM device, was extracted with chloroform/methanol containing internal standard and subjected to LC-MS/MS analysis of three selected PEth forms (16:0/16:0, 16:0/18:1, and 16:0/18:2). Chromatographic separation was achieved on a UPLC BEH phenyl column, using a mobile phase consisting of acetonitrile and water containing 10 mmol/L ammonium hydrogen carbonate with 0.1% ammonia. The MS instrument was operated in negative electrospray ionization and selected reaction monitoring mode.

RESULTS

The detection limit for PEth 16:0/16:0, 16:0/18:1, and 16:0/18:2 was ~0.1 ng/mL, and the extraction recoveries at 2.0 ng/mL were in the range of 99%-114%. Method linearity over a concentration range up to 200 ng/mL was ≥0.99. No significant deviation in results was observed in an analyte stability study of two different concentrations at two different temperatures over 3 months. In 35 oral fluid samples collected from patients undergoing alcohol detoxification, the highest concentration was observed for PEth 16:0/18:1 (Detected range, 0.51-55.3 ng/mL; mean, 8.5; median, 3.1). In addition, all three PEth forms were variably identified in a majority (63%) of the oral fluid samples. The PEth 16:0/18:1 values in oral fluid showed a weak positive correlation with the corresponding values in whole blood samples (r=0.50, p=0.026, n=20).

CONCLUSIONS

The LC-MS/MS method could reliably detect and quantify PEth in oral fluid samples collected after alcohol exposure. The method was characterized by validation data with satisfactory recovery, sensitivity, accuracy, and imprecision, and applied for analysis of clinical samples. The results suggest that measurement of PEth in oral fluid can be used as a biomarker for alcohol consumption, and as such a non-invasive complement to analysis in blood. However, further studies are required to evaluate the test characteristics (e.g. sensitivity and half-life) in comparison with PEth in blood.

Fast, Sensitive, and Quantitative Point-of-Care Platform for the Assessment of Drugs of Abuse in Urine, Serum, and Whole Blood

Drug abuse is a major public health problem in many countries in Europe and North America. Currently available platforms for drug abuse assessment are facing technical challenges of nonquantitation, inaccuracy, low throughput, incompatibility with diverse complex specimens, long assay times, and requirement of instrument and/or expertise for readout. Here, we report an integrated competitive volumetric-bar-chart chip (CV-Chip) to assay multiple drug targets at the point-of-care (POC). To the best of our knowledge, it is the first time that a POC platform has been demonstrated to fully address the above-mentioned limitations. We applied this integrated CV-chip platform to assay multiple drugs in 38 patient urine and serum samples and validated the on-chip results with an LC-MS/MS method, indicating a clinical sensitivity and specificity of 0.94 and 1.00, respectively. We further demonstrated that the combination of an on-chip blood separator with the CV-Chip enabled the platform to directly assay finger-prick whole blood samples, which have always been recognized as an ideal biospecimen for POC detections. In summary, this integrated CV-Chip is able to serve as a sensitive, accurate, fast, portable, readout visible, and minimally invasive platform for drug abuse assessment.

Incorporation of Zolpidem into Hair and Its Distribution after a Single Administration

To obtain fundamental information on the drug incorporation into hair, time-course changes in drug distribution along single-strand hair were observed after a single oral administration of zolpidem (ZP), one of the most frequently used hypnotic agents. Quantitative sectional hair analyses of 1-mm segments were performed for each single-strand hair using a validated LC-MS/MS procedure. ZP was detected in all specimens plucked at 10 and 24 hours after a single dose, and the distribution ranged over the whole hair root (4-5 mm in length). A significantly high concentration of ZP was detected in the hair bulb region, whereas much lower concentrations were widely observed in the upper part of the hair root of those samples; this suggested that the incorporation of ZP occurred in two regions, mainly in the hair bulb and to a lesser extent in the upper dermis zone. The ZP-positive area formed lengths of up to 10-12 mm after a single administration, indicating that its incorporation from the hair bulb would continue for about 2 weeks. Time-course changes in the ZP concentration in the hair root additionally revealed that only a small portion of ZP that initially concentrated in the bulb was successively incorporated into the hair matrix and moved toward the keratinized region as hair grew. These findings should be taken into account upon discussing individual drug-use history based on hair analysis. The matrix-assisted laser desorption/ionization mass spectrometry imaging of ZP in the same kinds of hair specimens was also successfully achieved.

Long-term stability of cannabinoids in oral fluid after controlled cannabis administration

Cannabinoid stability in oral fluid (OF) is important for assuring accurate results since OF has become a valid alternative matrix of choice for drug testing. We previously published OF cannabinoid stability studies using Quantisal™, Oral-Eze®, and StatSure™ devices stored at room temperature for 1 week, 4 °C for up to 4 weeks, and at -20 °C up to 24 weeks. Extending refrigerated stability up to 3 months would be helpful for clinical and forensic testing, for re-analysis of OF samples and for batching research analyses. Individual authentic OF pools were prepared after controlled smoking of a 6.9% ∆⁹ -tetrahydracannabinol cannabis cigarette; the Quantisal™ device was utilized for OF collection. Fifteen healthy volunteers participated in the Institutional Review Board-approved study. Stability for THC, 11-nor-9-carboxy-THC (THCCOOH), ∆⁹ -tetrahydrocannabivarin (THCV), cannabidiol (CBD), and cannabigerol (CBG) were determined after storage at 4 °C for 1, 2, and 3 months. Results within ±20% of baseline concentrations were considered stable. All analytes were stable for up to 2 months at 4 °C for all participants with positive baseline concentrations. Baseline concentrations were highly variable. In total, THC, THCCOOH, THCV, CBD, and CBG were stable for 3 months at 4 °C for pooled positive specimens from 14 of 15, 8 of 9, 7 of 8, 8 of 9, and 9 of 10 participants, respectively. In conclusion, Quantisal™-collected OF specimens should be stored at 4 °C for no more than two months to assure accurate THC, THCCOOH, THCV, CBD, and CBG quantitative results; only one participant's OF was unstable at three months. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

A Study on the Reliability of an On-Site Oral Fluid Drug Test in a Recreational Context

The reliability of DrugWipe 5A on site test for principal drugs of abuse (cannabis, amphetamines, cocaine, and opiates) detection in oral fluid was assessed by comparing the on-site results with headspace solid-phase microextraction (HS-SPME) gas chromatography-mass spectrometry (GC-MS) analysis on samples extracted by the device collection pad. Oral fluid samples were collected at recreational settings (e.g., discos, pubs, and music bars) of Rome metropolitan area. Eighty-three club goers underwent the on-site drug screening test with one device. Independently from the result obtained, a second device was used just to collect another oral fluid sample subsequently extracted and analyzed in the laboratory following HS-SPME procedure, gas chromatographic separation by a capillary column, and MS detection by electron impact ionization. DrugWipe 5A on-site test showed 54 samples (65.1%) positive to one or more drugs of abuse, whereas 75 samples (90.4%) tested positive for one or more substances following GC-MS assay. Comparing the obtained results, the device showed sensitivity, specificity, and accuracy around 80% for amphetamines class. Sensitivity (67 and 50%) was obtained for cocaine and opiates, while both sensitivity and accuracy were unsuccessful (29 and 53%, resp.) for cannabis, underlying the limitation of the device for this latter drug class.

Blood alcohol analysis alone versus comprehensive toxicological analysis - Systematic investigation of missed co-ingested other drugs in suspected alcohol-impaired drivers

Driving under the influence of alcohol and/or drugs (DUID) is a safety issue of increasing public concern. When a police officer has reasonable grounds to classify a driver as impaired, he may arrange for a blood sample to be taken. In many countries, alcohol analysis only is ordered if impairment is suspected to be exclusively due to alcohol while comprehensive toxicological screening will be performed if additional suspicion for other illegal drugs of abuse (DoA) or medicinal drugs is on hand. The aim of the present study was firstly to evaluate whether signs of impairment can be differentiated to be caused by alcohol alone or a combination of alcohol and other driving-impairing drugs and secondly to which extent additional drugs are missed in suspected alcohol-impaired drivers. A total of 293 DUID cases (negative n=41; alcohol positive only, n=131; alcohol+active drug positive, n=121) analyzed in 2015 in the Canton of Zurich were evaluated for their documented impairment symptoms by translating these into a severity score and comparing them applying principle component analysis (PCA). Additional 500 cases suspected for alcohol-impaired driving only were reanalyzed using comprehensive LC-MS/MS screening methods covering about 1500 compounds. Drugs detected were classified for severity of driving impairment using the classification system established in the DRUID study of the European Commission. As partly expected from the pharmacological and toxicological point of view, PCA analysis revealed no differences between signs of impairment caused by alcohol alone and those caused by alcohol plus at least one active drug. Breaking it down to different blood alcohol concentration ranges, only between 0.3 and 0.5g/kg trends could be observed in terms of more severe impairment for combined alcohol and drug intake. In the 500 blood samples retrospectively analyzed in this study, a total of 330 additional drugs could be detected; in some cases up to 9 co-ingested ones. In total, 37% of all cases were positive for additional drugs, thereby 15% of classic DoAs and further 9% of prescription drugs with a severe risk to cause driving impairment based on the DRUID classification system. A decision whether signs of impairment are related to alcohol alone or to the combination of alcohol and other drugs is impossible. Taking into consideration the high rate of missed drugs in DUI cases, police should think about increasing the number of DUID cases in countries were sanctioning differs between alcohol and alcohol plus drug impaired driving.

Compound identification in forensic toxicological analysis with untargeted LC-MS-based techniques

Untargeted LC-MS/MS techniques have become indispensable tools for systematic toxicological analysis. Compound identification is based on the mass spectrometric information obtained, and this may include m/z, isotopic pattern, retention time and fragmentation information. All these different kinds of analytical features can be stored in libraries and databases. Currently, the most competent approach for compound identification involves tandem mass spectral library search. State-of-the-art databases were shown to be sensitive, specific, robust and instrument-independent. Low- and high-resolution instruments can both be used to develop efficient screening workflows. For automated and unattended acquisition of tandem mass spectral data, data-dependent acquisition control is the method of choice. Due to their impressive detection sensitivity, data-independent acquisition techniques are finding increased applicability.