Methamphetamine as the most common concomitant substance used with pregabalin misuse.

BACKGROUND AND AIM: Non-medical use of Pregabalin (PGB) is a growing concern in many countries because of the serious consequences associated with their abuse. Judicial cases within the probation system, multiple drug users, and patients in treatment programs administered PGB at higher doses than suggested, commonly without prescription. For this reason, it is important to analyze PGB by adding it to the routine analysis scale in determining whether PGB is used for medical purposes or abuse. In this study, PGB analyzed (single or multiple substance use, concomitant substances) in urine samples of forensic and clinical cases by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In addition to the sociodemographic and clinical characteristics of pregabalin-positive cases, the results were evaluated separately from a clinical and forensic perspective. METHODS: All urine samples which was admitted to Addiction Toxicology Laboratory from 'drug abuse probation system' (forensic cases, n = 640) and from various departments of our hospital (clinical cases, n = 371) between December 2022 and April 2023. Screening analysis were carried out by immunoassay in total 1011 cases. LC-MS/MS method simultaneously analyzed amphetamine, benzoilecgonine, cocaine, codeine, metamphetamine, morphine, 3,4-metilenedioksi-N-metilamfetamin (MDMA), 11-nor-9-karboksi-Δ9-tetrahidrokannabinol and pregabalin in urine samples. PGB was added to the our routine substance screening analysis scale in December 2022 to detect pregabalin use. RESULTS: PGB was detected in 12.3% of probabition cases and 13.2% of clinical cases. The mean age of PGB positive cases was 26.55 ± 7,52 years old, predominantly males (%85,9). Single PGB was detected in 53.2% of forensic cases (n = 42), and 38.7% of clinical cases (n = 19). The most common substance detected concomitantly with PGB was amphetamine type stimulants (ATSs:amphetamine, methamphetamine, ecstasy/MDMA etc.) (22.8% of forensic cases and 46.9% of clinical cases), followed by concomitant cannabis use (24.1% of forensic cases and 26.5% of clinical cases). Concomitant opioid use was rare (1.3% of forensic cases and 4.1% of clinical cases). Detection of PGB was significantly different across months on which the samples were collected (x2 = 82.8, df=4, p < 0.001). CONCLUSION: Inconsistently with previous studies suggesting opioids as the most prevalant substances concominant with PGB, our results showed that stimulants (especially ATSs) were the most prevelant substances concominant with PGB, followed by cannabis. High proportion of PGB detection in probabition cases, frequently as a single substance abuse takes attention. These results suggest that PGB, may be used to avoid legal consequences. It is important for laboratories to be aware that they need to make changes as addition of newly abused substances in their analysis panels, when necessary, as differences between regions and cultures affect substance use patterns.

Does Labetalol Trigger False Positive Drug Testing Results?

OBJECTIVES: Labetalol, an α- and ß-adrenergic antagonist used to treat hypertension in pregnancy has been blamed for causing false-positive amphetamine and methamphetamine results. In this study, we tested 3 concentrations of labetalol prepared with 4 specimen types (urine, plasma, meconium, and umbilical cord tissue), for amphetamine, methamphetamine, and several other drugs with screen and confirmation tests. METHODS: Residual drug-free specimens were pooled. Labetalol hydrochloride dissolved in methanol was used to prepare spikes in triplicate per specimen type (2.7, 50, and 100 µM), which were tested with 41 previously validated drug tests performed by immunoassay or liquid chromatography tandem mass spectrometry (LC-MS/MS). RESULTS: Labetalol triggered false-positive amphetamine and methamphetamine results by immunoassay in meconium but did not trigger positive results for any of the targeted drugs or drug metabolites tested by LC-MS/MS. No positive results were generated by any immunoassay or LC-MS/MS test included in the study, when challenged with high concentrations of labetalol in urine, plasma, or umbilical cord tissue. CONCLUSIONS: In summary, false-positive results can be generated by labetalol when tested by immunoassay, but false-positive results are not expected when testing is performed by highly specific analytical approaches such as LC-MS/MS.

Qualitative Screening of Amphetamine- and Ketamine-Type Abuse Drugs in Urine Employing Dual Mode Extraction Column by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS-MS).

This manuscript reported a fast and rapid qualitative screening method for abuse drugs in urine by liquid chromatography-tandem mass spectrometry (LC-MS-MS). The scope of the abuse drugs under investigation included methamphetamine (MA), amphetamine (AMP), methylenedioxymethamphetamine (MDMA), methylenedioxyamphetamine (MDA), paramethoxymethamphetamine (PMMA), ephedrine, pseudoephedrine, ketamine (KET), deschloroketamine (DCK), 2-fluorodeschloroketamine (2 F-DCK) and deschloro-N-ethylketamine (2-oxo-PCE). The method employed a dual mode extraction (DME) column as a novel clean-up method for the urine matrix. To an aliquot of 0.2 mL urine, internal standards (ISTDs) and 0.4 mL of acidified methanol were added. After vortex and centrifugation, the supernatant was passed through a DME column before LC-MS-MS analysis. Chromatographic separation was achieved with a C18 column by gradient elution. The limits of detection (LODs) for MA, AMP, MDMA, MDA and PMMA were 3 ng/mL, whereas those for ephedrine and pseudoephedrine were 10 ng/mL and those for KET, DCK, 2 F-DCK and 2-oxo-PCE were 1 ng/mL. The matrix effects ranged from -12% to 7% (%CV from 4% to 19%). This method is fit for the intended purpose for forensic toxicology, as well as for forensic analysis of drugs facilitating sexual assault and other criminal acts.

Identification and Quantitative Analysis of 2-Fluoromethamphetamine and Its Metabolites in Human Urine.

Various synthetic drugs have appeared over the past years across the world, and phenethylamine derivatives are among them; indeed, aromatic fluoro analogs of methamphetamine and amphetamine have been in the illicit drug market since the early 2000s. Although they are currently widely abused across the world, little information is available on their metabolism and toxicology. Recently, we came across an alleged 2-fluoromethamphetamine (2-FMA) drug abuse case. The urine obtained from the alleged abuser was analyzed as part of a criminal investigation. 2-FMA, 2-fluoroamphetamine (2-FAP) and some related compounds were detected by liquid chromatography-tandem mass spectrometry. In forensic science, both an "unchanged" drug and its metabolite(s) need to be detected in urine to verify the illicit drug use. Notably, the detection of 2-FAP, which is a plausible 2-FMA metabolite, is insufficient as evidence of 2-FMA use because 2-FAP is widely available and may be present as such in taken liquids. In this study, we synthesized analytical standards for N-hydroxy 2-FMA (N-OH-2-FMA) and two diastereomers of 2-fluoroephedrine, which are plausible metabolites of 2-FMA. Using these standards, the urine specimen was found to contain N-OH-2FMA and one diastereomer of 2-fluoroephedrine; moreover, the concentrations of these compounds were successfully determined. The results of our study suggest that N-hydroxylation and aliphatic hydroxylation are the characteristic metabolic pathways of 2-FMA compared with that of methamphetamine. This evidence indicates that both N-OH-2-FMA and 2-fluoroephedrine are plausible candidates as analytical targets for drug-use certification in forensic science.

Derivatization-assisted immunoassays: application for group-specific detection of potent methamphetamine and amphetamine enantiomers.

Reliable and feasible tools for detecting (S)-methamphetamine [(S)-MAP] and (S)-amphetamine [(S)-AP] are required for regulating their illicit circulation. Antibodies that react equally to these stimulants are desirable for this purpose, but have been difficult to generate because of the crucial difference between their characteristic structures: i.e., N-methylamino (MAP) and amino (AP) groups. Furthermore, their small molecular masses (Mr < 150) have hampered the generation of high-affinity antibodies. To overcome these problems, we converted (S)-MAP and -AP into their 2-(trimethylsilyl)ethyl carbamate forms, Teoc-(S)-MAP and -AP, respectively, as surrogate analytes. The Teoc-derivatization not only increases their molecular masses, but also masks their structural differences. We generated a novel monoclonal antibody that showed a satisfactory affinity to Teoc-(S)-MAP residues (Kd = 13 nM as the IgG form) and developed a competitive enzyme-linked immunosorbent assay (ELISA) using microplates containing immobilized Teoc-(S)-MAP residues. Almost overlapping dose-response curves were obtained for Teoc-(S)-MAP and -AP, with the limit of detection of 0.078 and 0.10 ng per assay, respectively. A fixed amount of test powder sample (1 mg) was derivatized with Teoc-O-succinimidyl for 5 min, and subjected to ELISA using Teoc-(S)-MAP as the calibration standard. Under this protocol, (S)-MAP and -AP were converted to their Teoc derivatives with 30% and 34% yield, respectively, determined using ELISA as "Teoc-(S)-MAP equivalent," being distinguished from the derivatization products of (R)-MAP, (R)-AP, ephedrine, (S)-methylenedioxymethamphetamine, tyramine, dopamine, and ß-alanine. This ELISA detected as little as 10 µg of (S)-MAP and -AP, and (S)-MAP in urine obtained from (S)-MAP-administered rats. Immunochromatography devices were also developed using gold nanoparticles coated with the monoclonal antibody, with which 0.10 mg of (S)-MAP and -AP was detected by the naked eye. We conclude that the present derivatization-assisted immunoassays may be useful for the detection of (S)-MAP and/or -AP in early stage screening of suspicious substances.

The analytical performance of six urine drug screens on cobas 6000 and ARCHITECT i2000 compared to LC-MS/MS gold standard.

BACKGROUND: Immunoassays provide a rapid tool for the screening of drugs-of-abuse (DOA). However, results are presumptive and confirmatory testing is warranted. To reduce associated cost and delay, laboratories should employ assays with high positive and negative predictive values (PPVs and NPVs). Here, we compared the results of urine drug screens on cobas 6000 (cobas) and ARCHITECTi2000 (ARCHITECT) platforms for six drugs against LC-MS/MS to assess the analytical performance of these assays. METHODS: Eighty nine residual urine specimens, which tested positive for amphetamine, THC-COOH, benzoylecgonine, EDDP, opiates and/or oxycodone during routine drug testing, were stored frozen until later confirmation by LC-MS/MS. Immunoassays were performed on cobas and ARCHITECT using a split sample. A third aliquot from these samples was tested by LC-MS/MS to assess the percentage of false positive, false negative, true positive and true negative results and calculate the PPVs and NPVs for each immunoassay. RESULTS: The PPVs of THC-COOH and EDDP assays were 100% on both platforms. Suboptimal PPVs were achieved for oxycodone (cobas, 57.1% vs ARCHITECT, 66.7%), amphetamine (77.8 vs. 100%), opiates (80.0 vs. 84.6%) and benzoylecgonine (88.9 vs. 84.2%) assays. The NPV was 100% for cobas and ARCHITECT oxycodone assays. Lower NPVs were achieved for THC-COOH (cobas, 28.6% vs ARCHITECT, 25.0%), EDDP (72.7% for both assays), benzoylecgonine (74.4% vs 73.8%), amphetamine (83.3% vs 82.8%) and opiates (100% vs 85.3%). CONCLUSION: Overall, cobas and ARCHITECT urine drug screens have comparable analytical performance. Confirmatory testing is warranted for positive test results especially for oxycodone, amphetamine, opiates and cocaine. Negative drug screen results must be interpreted with caution especially for THC-COOH, EDDP, benzoylecgonine, amphetamine and opiates.

Are point-of-care urine drug testing devices suitable for antenatal drug screening? A study verifying the Alere® Drug Screen Test Cup for the detection of six classes of drug in a pregnant population.

BACKGROUND: Currently, there are no national guidelines for antenatal drug testing. At Colchester Hospital, we use a strategy of screen-only using point-of-care testing to detect illicit drug use in pregnancy. To determine the suitability of this approach, we have compared the results of urine analysis by point-of-care testing with another NHS specialist clinical toxicology service that uses confirmation mass spectrometry. METHODS: A total of 482 anonymized random urine specimens from antenatal clinics were tested for six drug classes: amphetamine, benzodiazepines, buprenorphine, cocaine, methadone and opiates using the Alere™ Drug Screen Urine Test Cup. The manufacturer's claims for positive cut-off and result stability were verified using spiked blank urine. Confirmatory testing was performed using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for detection of 26 individual drugs. RESULTS: Of 473 urine samples with adequate volume for point-of-care screening, 4.4% tested positive: 19 opiate and 2 cocaine. Concordance between point-of-care screening and UPLC-MS/MS confirmation was 97.9% for all drugs and 78.9% for opiates. Using spiked urine, only positive results for opiates were stable when read up to the manufacturer's recommended time of 60 min. CONCLUSIONS: The key advantages of using point-of-care devices to detect drug use in pregnancy are that is convenient and cheap. However, the clinical utility of point-of-care testing is limited by its poor sensitivity. Best practice is to confirm results using a more specific and sensitive method. As a result of this study, we are now reviewing our own procedures to consider introducing routine confirmation by mass spectrometry.

Tetracaine from urethral ointment causes false positive amphetamine results by immunoassay.

BACKGROUND: Amphetamine urine drug screening by immunoassay is prone to cross-react with other compounds leading to false positive results. Tetracaine is a local anesthetic drug used in the clinical setting as an ointment during urinary catheterization. In our laboratory, tetracaine is often detected by gas chromatography-mass spectrometry in the urine of patients admitted in the emergency department with false positive amphetamine results. The objectives of this study were to investigate if there was cross-reactivity to tetracaine in an amphetamine immunoassay and to retrospectively evaluate the potential contribution of tetracaine to false positive amphetamine results. METHODS: An interference study was conducted using negative urine samples spiked with increasing concentrations of tetracaine hydrochloride and analyzed with the CEDIA Amphetamine/Ecstasy immunoassay. Retrospectively, urine samples of patients which yielded positive amphetamine immunoassay results and were analyzed by gas chromatography-mass spectrometry were reviewed (n = 417). The presence of tetracaine and/or other drugs by gas chromatography-mass spectrometry were gathered. RESULTS: Tetracaine caused false positive amphetamine results by immunoassay (cut-off 1000 µg/L) with a concentration of above 40 mg/L. Retrospective analysis of all positive amphetamine immunoassay samples showed that in 45 out of the 417 (10.8%) urine samples no amphetamine-like derivative was identified by gas chromatography - mass spectrometry. In 37 out of 45 (82.2%) of these false positive cases tetracaine was detected, of whom 59.5% (22/37) had an estimated tetracaine concentration of ≥40 mg/L. CONCLUSIONS: This study confirmed the interference of tetracaine in the CEDIA Amphetamine/Ecstasy immunoassay and that tetracaine may have contributed to around 80% of the false positive amphetamine cases in the urine samples of patients admitted to the emergency department at our institution.

Urine drug-testing tampering approaches: Turkish probationers.

The growing numbers of individual and social problems associated with drug abuse necessitate new approaches in drug-testing systems. Equally, drug abusers may attempt to invalidate drug testing using different methods such as adulteration, dilution and substitution. This study aims to investigate tampering methods commonly used by Turkish substance-using probationers and evaluate their effects on toxicological drug-testing results. Initially, probationer urinary screening test results and laboratory substitution documents were evaluated to investigate the dilution and substitution attempt. Additionally, an experimental study was carried out by using readily available household products (bleach, vinegar, drain opener, eye drops) for adulteration. The effect of these agents was investigated for 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH), amphetamine and 3,4-methylenedioxymethamphetamine (MDMA). It was determined that probationers preferred unbranded products (syringes, nylon bottles, etc.) for urine substitution. To detect dilution, screening test results were evaluated along with creatinine values. The variability of mean creatinine values can change the rate of the before-negative and after-positive ratio. For adulteration method, the high amounts of bleach provided false-negative results for THC-COOH and amphetamine, but spiking in any concentration of bleach affected MDMA results, causing a slight increase. Vinegar did not affect the THC-COOH and amphetamine results. However, false-negative results were observed for MDMA, with high amounts of vinegar-spiked urine samples. Drain opener was added in large quantities, and false-negative results were observed for all analytes. Visine eye drops did not have any effect on THC-COOH or amphetamine, but a high quantity of eye drops had a slight decreasing effect for MDMA.

Efficacy of DRIVEN-FLOW® M7-II, a new on-site drug screening kit in postmortem urine compared with Triage DOA®.

The efficacy of DRIVEN-FLOW® M7-II(DFM7II) for seven drug groups was compared with Triage DOA® (Triage) using 340 autopsy urine samples taken from bodies within 1 month of death based on mass screening analysis of GC/MS and LC-MS/MS. The sensitivity to benzodiazepines was 0.56 in Triage and 0.53 in DFM7II with few false positives, and their accuracy was 0.88. Triage detected triazolo diazepine derivatives more easily than DFM7II. DFM7II detected diazepam and nitro benzodiazepines more easily than Triage. There were nine amphetamine false-positive cases of more than 10 days after death in Triage, but these were absent in DFM7II during this period. The accuracy of amphetamines for Triage was 0.96 and for DFM7II was 1. Tricyclic antidepressant (TCA) was detected in five cases by mass analysis, while there were four false-positive cases using Triage and eight cases using DFM7II. In the TCA false-positive cases of both kits, tricyclic psychotics such as chlorpromazine, carbamazepine, and quetiapine were included as well as the drug poisoning cases. There were no samples containing cocaine or THC. The accuracy of DFM7II for opiate and barbiturates was 1, but those of Triage was less than 1. Based on the above, DFM7II is a more accurate kit with fewer false-positives for target drug groups, other than TCA, than Triage.

A Molecularly Imprinted Polymer-based Dye Displacement Assay for the Rapid Visual Detection of Amphetamine in Urine.

The rapid sensing of drug compounds has traditionally relied on antibodies, enzymes and electrochemical reactions. These technologies can frequently produce false positives/negatives and require specific conditions to operate. Akin to antibodies, molecularly imprinted polymers (MIPs) are a more robust synthetic alternative with the ability to bind a target molecule with an affinity comparable to that of its natural counterparts. With this in mind, the research presented in this article introduces a facile MIP-based dye displacement assay for the detection of (±) amphetamine in urine. The selective nature of MIPs coupled with a displaceable dye enables the resulting low-cost assay to rapidly produce a clear visual confirmation of a target's presence, offering huge commercial potential. The following manuscript characterizes the proposed assay, drawing attention to various facets of the sensor design and optimization. To this end, synthesis of a MIP tailored towards amphetamine is described, scrutinizing the composition and selectivity (ibuprofen, naproxen, 2-methoxphenidine, quetiapine) of the reported synthetic receptor. Dye selection for the development of the displacement assay follows, proceeded by optimization of the displacement process by investigating the time taken and the amount of MIP powder required for optimum displacement. An optimized dose-response curve is then presented, introducing (±) amphetamine hydrochloride (0.01-1 mg mL-1) to the engineered sensor and determining the limit of detection (LoD). The research culminates in the assay being used for the analysis of spiked urine samples (amphetamine, ibuprofen, naproxen, 2-methoxphenidine, quetiapine, bupropion, pheniramine, bromopheniramine) and evaluating its potential as a low-cost, rapid and selective method of analysis.

Use of Amphetamine-Type Stimulants Among Emergency Department Patients With Untreated Opioid Use Disorder.

STUDY OBJECTIVE: Concurrent use of amphetamine-type stimulants among individuals with opioid use disorder can exacerbate social and medical harms, including overdose risk. The study evaluated rates of amphetamine-type stimulant use among patients with untreated opioid use disorder presenting at emergency departments in Baltimore, MD; New York, NY; Cincinnati, OH; and Seattle, WA. METHODS: Emergency department (ED) patients with untreated opioid use disorder (N=396) and enrolled between February 2017 and January 2019 in a multisite hybrid type III implementation science study were evaluated for concurrent amphetamine-type stimulant use. Individuals with urine tests positive for methamphetamine, amphetamine, or both were compared with amphetamine-type stimulant-negative patients. RESULTS: Overall, 38% of patients (150/396) were amphetamine-type stimulant positive; none reported receiving prescribed amphetamine or methamphetamine medications. Amphetamine-type stimulant-positive versus -negative patients were younger: mean age was 36 years (SD 10 years) versus 40 years (SD 12 years), 69% (104/150) versus 46% (114/246) were white, 65% (98/150) versus 54% (132/246) were unemployed, 67% (101/150) versus 49 (121/246) had unstable housing, 47% (71/150) versus 25% (61/245) reported an incarceration during 1 year before study admission, 60% (77/128) versus 45% (87/195) were hepatitis C positive, 79% (118/150) versus 47% (115/245) reported drug injection during 1 month before the study admission, and 42% (62/149) versus 29% (70/244) presented to the ED for an injury. Lower proportions of amphetamine-type stimulant-positive patients had cocaine-positive urine test results (33% [50/150] versus 52% [129/246]) and reported seeking treatment for substance use problems as a reason for their ED visit (10% [14/148] versus 19% [46/246]). All comparisons were statistically significant at P<.05 with the false discovery rate correction. CONCLUSION: Amphetamine-type stimulant use among ED patients with untreated opioid use disorder was associated with distinct sociodemographic, social, and health factors. Improved ED-based screening, intervention, and referral protocols for patients with opioid use disorder and amphetamine-type stimulant use are needed.

Intoxicaciones por anfetamina y metanfetamina atendidas en los servicios de urgencias: características clínicas y utilidad de la confirmación analítica / Amphetamine and methamphetamine poisonings attended by emergency services: clinical characteristics and the usefulness of laboratory confirmation

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Drug Use by Music Festival Attendees: A Novel Triangulation Approach Using Self-Reported Data and Test Results of Oral Fluid and Pooled Urine Samples.

Background: Self-reported data are commonly used when investigating illicit substance use. However, self-reports have well-known limitations such as limited recall and socially desirable responding. Mislabeling or adulteration of drugs on the illicit market may also cause incorrect reporting. Objectives: We aimed to examine what could be gained in terms of illicit drug use findings among music festival attendees when including biological sample test results in the assessment. Methods: We included 651 attendees at three music festivals in Norway from June to August 2016. Self-reported drug use was recorded using questionnaires, and samples of oral fluid were analyzed to detect use of illicit drugs. In addition, we analyzed samples of pooled urine from portable toilets at each festival. Results: All methods identified cannabis, MDMA, and cocaine as the most commonly used drugs. Overall, 6.6% of respondents reported use of illicit substances during the previous 48 hours. Oral fluid testing identified a larger number of drug users as 12.6% tested positive for illicit drugs. In oral fluid testing, we identified ketamine and three new psychoactive substances (NPS) that had not been reported on the questionnaire. In pooled urine testing, we identified amphetamine and three additional NPS that were neither reported used nor found in oral fluid samples. Conclusions/Importance: Drug testing of biological samples proved to be an important supplement to self-reports as a larger number of illicit substances could be detected.

A complicated case of bowel obstruction with sepsis and methamphetamine toxicity in a child with pica.

In this report, a pediatric case of bowel obstruction with sepsis complicated by methamphetamine toxicity is described. The decedent, an eleven-year-old female with a clinical history of pica, was found unresponsive in her home and pronounced dead following unsuccessful resuscitative efforts. Radiologic imaging showed multiple radio-opaque foreign objects in the stomach and bowel. Autopsy revealed a green leafy substance, coins and other metallic items, folded paper, and plastic in her stomach and bowels. Postmortem iliac blood and urine tested positive for amphetamine and methamphetamine. While the decedent's medical history and autopsy findings provided evidence consistent with bowel obstruction with sepsis due to the ingestion of foreign materials, the high methamphetamine concentration was suggestive of concurrent methamphetamine toxicity. Unique complications associated with this case include the phenomenon that methamphetamine toxicity and bowel obstruction can present similarly in children and the reported opinion that accidental drug ingestion is uncommon in children over the age of five. This case emphasizes that the age range for suspected accidental drug ingestion should be expanded for those with pica, as these patients, despite being older, may not be able to differentiate between what they should and should not ingest. Furthermore, when treating a pediatric patient with pica that appears to present with bowel obstruction, unintentional drug ingestion should also be considered, particularly if there is a suspicion that the child lives in a household where drugs are abused, given the prospect that drug toxicity can present similarly.

Determination of amphetamine-type stimulants in urine samples using microextraction by packed sorbent and gas chromatography-mass spectrometry.

The aim of this work was the development, optimization and full validation of a method applying microextraction by packed sorbent (MEPS) coupled to gas chromatography-mass spectrometry (GC-MS) to determine amphetamine (AMP), methamphetamine (MAMP), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxyethylmethamphetamine (MDMA), 3,4-methylenedioxy-N-methyl-α-ethylfenilethylamine (MBDB), and 3,4-methylenedioxy-N-ethylamphetamine (MDE) in urine samples. Using 200 µL of sample, the MEPS procedure was optimized concerning type of sorbent, sample dilution, number of strokes, activation of the ion exchange mechanism and composition of both washing and elution solvents. The method was fully validated according to the Food and Drug Administration and the Scientific Working Group of Forensic Toxicology guidelines for the validation of bioanalytical methods. The studied parameters included selectivity, calibration model and linearity, limits of detection and quantification, precision, accuracy, stability, dilution integrity and recoveries. Linearity was obtained in the range of 25-1000 ng/mL for MAMP, MBDB and MDE, 35-1000 ng/mL for AMP and MDMA, and 50-1000 ng/mL for MDA, with coefficients of determination (R2) >0.99 for all analytes. Both intra- and inter-day precision and accuracy were adequate, and coefficients of variation lower than 15% and mean relative errors (RE) within a range of ±15% of the theoretical concentrations were obtained for all compounds under study. Analyte recoveries ranged from 19 to 71%, allowing LLOQs ≤50 ng/mL.

A Novel Liquid Chromatography Tandem Mass Spectrometry Technique using Multi-Period-Multi-Experiment of MRM-EPI-MRM3 with Library Matching for Simultaneous Determination of Amphetamine Type Stimulants Related Drugs in Whole Blood, Urine and Dried Blood Stain (DBS)-Application to Forensic Toxicology Cases in Malaysia.

A novel mass spectrometry detection technique based on a multi-period and multi- experiment (MRM-EPI-MRM3) with library matching in a single run for fast and rapid screening and identification of amphetamine type stimulants (ATS) related drugs in whole blood, urine and dried blood stain was developed and validated. The ATS-related drugs analyzed in this study include ephedrine, pseudoephedrine, amphetamine, methamphetamine, MDMA (3,4-Methylenedioxymethamphetamine), MDA (3,4-Methylenedioxyamphetamine), MDEA (3,4-Methylenedioxy-N-ethylamphetamine) and phentermine. The relative standard deviation for inter and intraday was less than 15% while recoveries ranged from 80% to 120% for all three matrices, i.e., whole blood, urine and dried blood stain. All compounds gave library matching percentage of more than 85% based on the purity. This method was proven to be simple and robust, and provide high confident results complemented with library matching confirmation.

Determination of several synthetic cathinones and an amphetamine-like compound in urine by gas chromatography with mass spectrometry. Method validation and application to real cases.

Most routine practices for drugs-of-abuse testing do not include screening procedures for new psychoactive substances, despite their increasing diffusion, preventing clear knowledge of the real consumption of these drugs in the populations. To make up for this shortcoming, a gas chromatography with mass spectrometry method was developed for the simultaneous determination of 18 synthetic cathinones and one amphetamine-like compound in human urine. The sample preparation was based on liquid-liquid extraction under alkaline condition followed by derivatization with trifluoroacetic anhydride. The separation of the 19 analytes was achieved in less than 10 min. The whole methodology was validated according to national and international guidelines. Selectivity, linearity range, limit of detection and limit of quantitation, precision and accuracy were evaluated. For all the analytes, the calibration curve was linear in the 100-1000 ng/mL concentration range. The limits of detection ranged from 10 to 30 ng/mL and limits of quantitation from 30 to 100 ng/mL. Precisions were in the ranges 0.1-10.4%, and 1.0-12.1% for low (100 ng/mL) and high (1000 ng/mL) concentration, respectively. The accuracy, expressed as bias% was within ±20% for all the analytes. The present method was successfully applied to urine samples originating from autopsies, drug abuse/withdrawal controls, clinical investigations, roadside controls, driving re-licensing, and workplace testing.

Efficient determination of amphetamine and methylamphetamine in human urine using electro-enhanced single-drop microextraction with in-drop derivatization and gas chromatography.

An efficient method for the determination of amphetamine (AM) and methylamphetamine (MA) using electro-enhanced single-drop microextraction (EE-SDME) and gas chromatography has been developed. One advantage of this method is that the extraction efficiency is greatly enhanced by the electric field acceleration of the mass transfer of target analytes from the sample solution to the organic solvent drop. In addition, the extracted analytes were in situ derivatized with isobutyl chloroformate (IBCF) in the droplet, which further improved the sensitivity of this method. Under the optimum conditions, the enrichment factors (EFs) for AM and MA were 247 and 782, respectively. The proposed method exhibited low limits of detection (0.27 µg/L for AM and 0.14 µg/L for MA) and good linearity over the concentration range between 1 and 2000 µg/L with regression coefficients (r2) of more than 0.99. The intra- and interday recoveries were from 89.6 to 96.2% and 82.7-90.5%, respectively, and the intra- and interday precisions (RSDs) were from 5.2 to 8.3% and 8.9-12.8%. The proposed method was applied to the determination of amphetamines in a urine sample.