Novel Receptor-Binding-Based Assay for the Detection of Opioids in Human Urine Samples.

Consumption of opioids is a growing global health problem. The gold standard for drugs of abuse screening is immunochemical assays. However, this method comes with some disadvantages when screening for a wide variety of opioids. Detection of the binding of a compound at the human µ-opioid receptor (MOR) offers a promising alternative target. Here, we set up a urine assay to allow for detection of compounds that bind at the MOR, thus allowing the assay to be utilized as a screening tool for opioid intake. The assay is based on the incubation of MOR-containing cell membranes with the selective MOR-ligand DAMGO and urine. After filtration, the amount of DAMGO in the eluate is analyzed by liquid chromatography tandem mass spectroscopy (LC-MS/MS). The absence of DAMGO in the eluate corresponds to a competing MOR ligand in the urine sample, thus indicating opiate/opioid intake by the suspect. Sensitivity and specificity were determined by the analysis of 200 consecutive forensic routine casework urine samples. A pronounced displacement of DAMGO was observed in 29 of the 35 opiate/opioid-positive samples. Detection of fentanyl intake proved to be the most challenging aspect. Applying a cut-off value of, e.g., 10% DAMGO binding would lead to a sensitivity of 83% and a specificity of 95%. Consequently, the novel assay proved to be a promising screening tool for opiate/opioid presence in urine samples. The nontargeted approach and possible automation of the assay make it a promising alternative to conventional methods.

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.

Effects of time-based administration of abstinence reinforcement targeting opiate and cocaine use.

Polydrug use is a common problem among patients in opioid-substitution treatment. Polydrug use has been reduced by administering abstinence-reinforcement contingencies in a sequence, such that a single drug is targeted until abstinence is achieved, and then an additional drug is targeted. The present study examined effects of administering abstinence-reinforcement contingencies sequentially based on time rather than on achieved abstinence. Participants accessed paid work (about $10/hr maximum) in the Therapeutic Workplace by providing urine samples 3 times per week. The urine samples were tested for opiates and cocaine. During an induction period, participants earned maximum pay independent of drug abstinence. Then, maximum pay depended upon urine samples that were negative for opiates. Two weeks later, maximum pay depended upon urine samples that were negative for both opiates and cocaine. Opiate and cocaine abstinence increased following administration of the respective contingencies. The time-based administration of abstinence reinforcement increased opiate and cocaine abstinence.

A Study of Opiate, Opiate Metabolites and Antihistamines in Urine after Consumption of Cold Syrups by LC-MS/MS.

Studying the origin of opiate and/or opiate metabolites in individual urine specimens after consumption of cold syrups is vital for patients, doctors, and law enforcement. A rapid liquid chromatography-tandem mass spectrometry method using "dilute-and-shoot" analysis without the need for extraction, hydrolysis and/or derivatization has been developed and validated. The approach provides linear ranges of 2.5-1000 ng mL-1 for 6-acetylmorphine, codeine, chlorpheniramine, and carbinoxamine, 2.5-800 ng mL-1 for morphine and morphine-3-ß-d-glucuronide, and 2.5-600 ng mL-1 for morphine-6-ß-d-glucuronide and codeine-6-ß-d-glucuronide, with excellent correlation coefficients (R2 > 0.995) and matrix effects (< 5%). Urine samples collected from the ten participants orally administered cold syrups were analyzed. The results concluded that participants consuming codeine-containing cold syrups did not routinely pass urine tests for opiates, and their morphine-codeine concentration ratios (M/C) were not always < 1. In addition, the distribution map of the clinical total concentration of the sum of morphine and codeine against the antihistamines (chlorpheniramine or carbinoxamine) were plotted for discrimination of people who used cold syrups. The 15 real cases have been studied by using M/C rule, cutoff value, and distribution map, further revealing a potential approach to determine opiate metabolite in urine originating from cold syrups.

Simultaneous Quantitation of Methamphetamine, Ketamine, Opiates and their Metabolites in Urine by SPE and LC-MS-MS.

Heroin, methamphetamine and ketamine have been the most commonly abused drugs in Taiwan. The presence of these drugs and their metabolites in postmortem specimens has been routinely monitored in our laboratory mostly by gas chromatographic-mass spectrometric methods. This study aimed to evaluate a more effective approach to simultaneously quantify these analytes (i.e., amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), morphine, codeine, 6-acetylmorphine, 6-acetylcodeine, ketamine and norketamine) in postmortem urine and blood specimens by liquid chromatography-tandem mass spectrometry (LC-MS-MS). Samples (1 mL) were extracted via solid-phase extraction, evaporated and reconstituted in the mobile phase for injection into the LC-MS-MS system. Respective deuterated analogs of these analytes were used as internal standards. Chromatographic separation was achieved by an Agilent Zorbax SB-Aq analytical column at 50°C. Mass spectrometric analysis was performed by electrospray ionization in positive-ion dynamic multiple reaction monitoring mode with optimized collision energy for respective precursor ion selected for each analyte, and the monitoring of two transition ions. Performance characteristics were assessed using drug-free samples that were fortified with 50-1,000 ng/mL of the 10 analytes. Analytical parameters evaluated and resulting data are as follows: (i) average extraction recoveries (n= 3) were better than 80%, except for MDMA (71%) and morphine (74%); (ii) inter-day and intra-day precision ranges (%CV) were 1.59-8.80% and 0.57-3.89%, respectively; (iii) calibration linearity (r2), detection limit and quantitation limit for all analytes were >0.999, 1 and 5 ng/mL, respectively; (iv) matrix effects (ion suppression) were observed for three analytes, but were satisfactorily compensated for by the deuterated internal standards adopted in the analytical protocol. This method was successfully applied to the analysis of specimens collected from unknown death cases from various district prosecutors' offices in Taiwan, and was also found helpful to understanding whether the detected opiates were derived from heroin or legal morphine/codeine-containing medications.

Evaluation of the Triage TOX Drug Screen Assay for Detection of 11 Drugs of Abuse and Therapeutic Drugs.

The demand for rapid and broad clinical toxicology screens is on the rise. Recently, a new rapid toxicology screening test, the Triage TOX Drug Screen (Alere Inc., USA), which can simultaneously detect 11 drugs of abuse and therapeutic drugs with an instrument-read cartridge, was developed. In the present study, we evaluated the efficacy of this new on-site immunoassay using 105 urine specimens; the results were compared with those obtained by using ultra-performance liquid chromatography with tandem mass spectrometry (UPLC-TMS). Precision was evaluated according to the CLSI EP12-A2 for analyte concentrations near the cutoff, including C50 and±30% of C50, for each drug using standard materials. The C50 specimens yielded 35-65% positive results and the±30% concentration range of all evaluated drugs encompassed the C5-C95 interval. The overall percent agreement of the Triage TOX Drug Screen was 92.4-100% compared with UPLC-TMS; however, the Triage TOX Drug Screen results showed some discordant cases including acetaminophen, amphetamine, benzodiazepine, opiates, and tricyclic antidepressants. The overall performance of the Triage TOX Drug Screen assay was comparable to that of UPLC-TMS for screening of drug intoxication in hospitals. This assay could constitute a useful screening method for drugs of abuse and therapeutic drugs in urine.

Monitoring Intravenous Abuse of Methadone or Buprenorphine in Opiate Maintenance Treatment (OMT): A Simple and Fast LC-MS-MS Method for the Detection of Disaccharides in Urine Samples.

The detection of disaccharides in urine is under investigation to act as a marker for intravenous abuse of disaccharide formulations, like liquid methadone with syrup (sucrose), methadone tablets (lactose and sucrose), or buprenorphine tablets (lactose). As the detection time in urine has not yet been investigated and a routine method for detecting disaccharides is still lacking, a study was performed to estimate the window of detection in urine after intravenous consumption of disaccharides. Furthermore, an analytical LC-MSMS method for the quantification of sucrose and lactose in urine was validated. The method was applied to urine samples of intravenous substitute consumers, with urine being sampled before intravenous use of substitutes and approximately 30 minutes later. Twenty users provided information regarding their most recent prior intravenous consumption. Disaccharides were detectable in all 20 urine samples about 30 minutes after consumption. A cut off for both disaccharides of 40mg/L was used. Based on these conditions 81% of the persons who consumed in a time frame of 24 hours ago showed positive results for disaccharides. The study showed that the validated LC-MSMS method with an easy and fast workup is usable for daily routine in the laboratory. It might be helpful for methadone and buprenorphine prescribing physicians to check whether the opiate maintenance treatment patient takes his or her substitution medicines orally as intended, or continues with intravenous misuse by injecting substitution medicines instead of heroin.

Degradation of Opioids and Opiates During Acid Hydrolysis Leads to Reduced Recovery Compared to Enzymatic Hydrolysis.

Drug monitoring laboratories utilize a hydrolysis process to liberate the opiates from their glucuronide conjugates to facilitate their detection by tandem mass spectrometry (MS). Both acid and enzyme hydrolysis have been reported as viable methods, with the former as a more effective process for recovering codeine-6-glucuronide and morphine-6-glucuronide. Here, we report concerns with acid-catalyzed hydrolysis of opioids, including a significant loss of analytes and conversions of oxycodone to oxymorphone, hydrocodone to hydromorphone and codeine to morphine. The acid-catalyzed reaction was monitored in neat water and patient urine samples by liquid chromatography-time-of-flight and tandem MS. These side reactions with acid hydrolysis may limit accurate quantitation due to loss of analytes, possibly lead to false positives, and poorly correlate with pharmacogenetic profiles, as cytochrome P450 enzyme (CYP2D6) is often involved with oxycodone to oxymorphone, hydrocodone to hydromorphone and codeine to morphine conversions. Enzymatic hydrolysis process using the purified, genetically engineered ß-glucuronidase (IMCSzyme®) addresses many of these concerns and demonstrates accurate quantitation and high recoveries for oxycodone, hydrocodone, oxymorphone and hydromorphone.

Importance of Urinary Drug Screening in the Multiple Sleep Latency Test and Maintenance of Wakefulness Test.

STUDY OBJECTIVES: Multiple sleep latency testing (MSLT) and the maintenance of wakefulness test (MWT) are gold-standard objective tests of daytime sleepiness and alertness; however, there is marked variability in their interpretation and practice. This study aimed to determine the incidence of positive drug screens and their influence on MSLT, MWT, and polysomnographic variables. METHODS: All patients attending Eastern Health Sleep Laboratory for MSLT or MWT over a 21-mo period were included in the study. Urinary drug screening for amphetamines, barbiturates, benzodiazepines, cannabinoids, cocaine, methadone, and opiates was performed following overnight polysomnography (PSG). Demographics and PSG variables were compared. RESULTS: Of 69 studies, MSLT (43) and MWT (26), 16% of patients had positive urinary drug screening (7 MSLT; 4 MWT). Drugs detected included amphetamines, cannabinoids, opiates, and benzodiazepines. No patient self-reported use of these medications prior to testing. No demographic, MSLT or MWT PSG data or overnight PSG data showed any statistical differences between positive and negative drug screen groups. Of seven MSLT patients testing positive for drug use, one met criteria for the diagnosis of narcolepsy and five for idiopathic hypersomnia. On MWT, three of the four drug-positive patients had a history of a motor vehicle accident and two patients were occupational drivers. CONCLUSIONS: These findings indicate drug use is present in patients attending for daytime testing of objective sleepiness and wakefulness. These data support routine urinary drug screening in all patients undergoing MSLT or MWT studies to ensure accurate interpretation in the context of illicit and prescription drug use.

Definitive Drug and Metabolite Screening in Urine by UPLC-MS-MS Using a Novel Calibration Technique.

Drug screening is an essential analytical tool for detection of therapeutic, illicit and emerging drug use. Presumptive immunoassay screening is widely used, while initial definitive testing by chromatography-coupled mass spectrometry is hampered due to complex pre-analysis steps, long chromatography time and matrix effects. The aim of this study is to develop and validate a definitive test for rapid and threshold accurate screening of 33 drugs or metabolites (analytes) in urine. Sample preparation in a 96-well plate format involves rapid glucuronidase hydrolysis followed by dilution, filtration and ultra-performance liquid chromatography-MS-MS analysis. Chromatographic separation, on an ACQUITY UPLC® BEH phenyl column is optimized for a 3-min MS-MS ion acquisition. Matrix effect was normalized by an innovative technique called threshold accurate calibration employing an additional analysis with an analyte spike as an internal standard undergoing the same matrix effect as an analyte in a drug-positive donor specimen. Accuracy and precision, at above and below threshold concentrations, were determined by replicate analysis of control urine pools containing 50, 75, 125 and 150% of threshold concentrations. Accuracy and selectivity were further demonstrated by concordant findings in proficiency and confirmatory testing. The study shows the applicability of definitive testing as an alternative to immunoassay screening and demonstrates a new approach to normalization of matrix effect.

Evaluation of a Newly Formulated Enzyme Immunoassay for the Detection of Hydrocodone and Hydromorphone in Pain Management Compliance Testing.

A new Hydrocodone Enzyme Immunoassay (HEIA; Lin-Zhi International, Inc.) was evaluated for the detection of hydrocodone and its main metabolite, hydromorphone. All specimens were tested with two different cutoff calibrators, 100 and 300 ng/mL, on an ARCHITECT Plus c4000 Clinical Chemistry Analyzer. Controls containing -25% (negative control) and +25% (positive control) of the cutoff calibrators and a drug-free control were analyzed with each batch. All 1,025 urine specimens were previously analyzed by ultra-performance liquid chromatography-mass spectrometry/mass spectrometry (UPLC-MS-MS) for opiates. Approximately, 33% (337/1,019) of the specimens yielded positive results by the HEIA assay at a cutoff concentration of 100 ng/mL and 19% (190/1,025) yielded positive results at the 300 ng/mL cutoff concentration. Of these presumptive positive specimens, UPLC-MS-MS confirmed the presence of hydrocodone and/or hydromorphone >100 ng/mL in 241 specimens and >300 ng/mL in 162 specimens, for each respective cutoff. With the 100 ng/mL cutoff, the HEIA demonstrated a sensitivity of 0.959, a specificity of 0.846 and an overall agreement with the UPLC-MS-MS of 87%. At 300 ng/mL cutoff, the HEIA demonstrated a sensitivity of 0.880, a specificity of 0.966 and an overall agreement of UPLC-MS-MS results of 95%. The Lin-Zhi HEIA 100 ng/mL cutoff assay demonstrated sensitivity for the detection of hydrocodone and hydromorphone in urine. The 300 ng/mL cutoff was less sensitive, but more selective, and should be part of an initial immunoassay screen, particularly in pain management compliance testing.

Predictive Value of Positive Drug Screening Results in an Urban Outpatient Population.

Urine drug testing (UDT) has become an essential component in the management of patients prescribed opioid analgesics for the treatment of chronic non-malignant pain. Several laboratory methods are available to monitor adherence with the pharmacological regimen and abstinence from illicit or unauthorized medications. Immunochemical screening methods are rapid and economical, but they have limitations, including lack of specificity, and confirmatory methods are often necessary to verify presumptive positive results. We analyzed the results of confirmatory assays in an outpatient setting to determine the predictive value of presumptive positive urine drug screen results using an automated immunoassay for eight common drugs or drug classes. Positive predictive values (PPVs), in descending order, were as follows: cannabinoids (100%), cocaine (100%), opiates (86.8%), benzodiazepines (74.6%), oxycodone (67.6%), methadone (44.1%) and amphetamines (9.3%). The number of positive barbiturate results was too small to be included in the statistical analysis.

Rapid screening for drugs of abuse in biological fluids by ultra high performance liquid chromatography/Orbitrap mass spectrometry.

We present a UPLC(®)-High Resolution Mass Spectrometric method to simultaneously screen for nineteen benzodiazepines, twelve opiates, cocaine and three metabolites, and three "Z-drug" hypnotic sedatives in both blood and urine specimens. Sample processing consists of a high-speed, high-temperature enzymatic hydrolysis for urine samples followed by a rapid supported liquid extraction (SLE). The combination of ultra-high resolution chromatography with high resolution mass spectrometry allows all 38 analytes to be uniquely detected with a ten minute analytical run. Limits of detection for all target analytes are 3ng/mL or better, with only 0.3mL of specimen used for analysis. The combination of low sample volume with fast processing and analysis makes this method a suitable replacement for immunoassay screening of the targeted drug classes, while providing far superior specificity and better limits of detection than can routinely be obtained by immunoassay.

LC-MS-MS Method for Analysis of Opiates in Wastewater During Football Games II.

Continuing our previous studies analyzing drugs of abuse in municipal wastewater, a method was developed for the analysis of opiates in wastewater samples using liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS). Eight opiate drugs and metabolites were analyzed including codeine, hydrocodone, hydromorphone, 6-monoacetylmorphine (6-MAM, the primary urinary metabolite of heroin), morphine, norhydrocodone (the primary urinary metabolite of hydrocodone), oxycodone and oxymorphone. These drugs were chosen because of their widespread abuse. Wastewater samples were collected at both the Oxford Waste Water Treatment Plant in Oxford, Mississippi (MS) and the University Wastewater Treatment Plant in University, MS. These wastewater samples were collected on weekends in which the Ole Miss Rebel football team held home games (Vaught-Hemingway Stadium, University, MS 38677). The collected samples were analyzed using a validated method and found to contain codeine, hydrocodone, hydromorphone, morphine, norhydrocodone, oxycodone and oxymorphone. None of the samples contained 6-MAM.

[Alimentary intake of opioid alkaloids by horses. Hazards due to poppy-containing feeds]. / Alimentäre Aufnahme von Opioid-Alkaloiden durch Pferde. Gefahren durch mohnhaltige Futtermittel.

Opioid alkaloids were identified in the urine of horses during an anti-doping control and in a case of intoxication. In both cases, it was suspected that the horses had ingested poppy-contaminated feed. To verify this suspicion, possible opioid alkaloid sources in Germany were identified through a literature research. Additionally, the contaminated feed was botanically and chemically analysed. The results indicated that both cases were most probably caused by the poppy in the feed. This highlights the previously underestimated risk of an intake of poppy-contaminated feed in horses. Recommendations are formulated for the prevention of positive doping-test results and intoxications by poppy-contaminated feeds in horses. Furthermore, a threshold for morphine in urine samples in competing horses is proposed.

Rapid screening of drugs of abuse in human urine by high-performance liquid chromatography coupled with high resolution and high mass accuracy hybrid linear ion trap-Orbitrap mass spectrometry.

A novel analytical toxicology method has been developed for the analysis of drugs of abuse in human urine by using a high resolution and high mass accuracy hybrid linear ion trap-Orbitrap mass spectrometer (LTQ-Orbitrap-MS). This method allows for the detection of different drugs of abuse, including amphetamines, cocaine, opiate alkaloids, cannabinoids, hallucinogens and their metabolites. After solid-phase extraction with Oasis HLB cartridges, spiked urine samples were analysed by HPLC/LTQ-Orbitrap-MS using an electrospray interface in positive ionisation mode, with resolving power of 30,000 full width at half maximum (FWHM). Gradient elution off of a Hypersil Gold PFP column (50mm×2.1mm) allowed to resolve 65 target compounds and 3 internal standards in a total chromatographic run time of 20min. Validation of this method consisted of confirmation of identity, selectivity, linearity, limit of detection (LOD), lowest limits of quantification (LLOQ), accuracy, precision, extraction recovery and matrix effect. The regression coefficients (r(2)) for the calibration curves (LLOQ - 100ng/mL) in the study were ≥0.99. The LODs for 65 validated compounds were better than 5ng/ml except for 4 compounds. The relative standard deviation (RSD), which was used to estimate repeatability at three concentrations, was always less than 15%. The recovery of extraction and matrix effects were above 50 and 70%, respectively. Mass accuracy was always better than 2ppm, corresponding to a maximum mass error of 0.8 millimass units (mmu). The accurate masses of characteristic fragments were obtained by collisional experiments for a more reliable identification of the analytes. Automated data analysis and reporting were performed using ToxID software with an exact mass database. This procedure was then successfully applied to analyse drugs of abuse in a real urine sample from subject who was assumed to be drug addict.

How can a methadone and an opiate-positive immunoassay result be reconciled in a patient prescribed only OxyContin and Wellbutrin?

Appropriate management of patients in pain clinics can be complex and sometimes confusing because providers must correctly interpret multiple sources of patient information. The correct interpretation of laboratory results is essential to guide subsequent patient treatment and management; however, laboratory and clinical pictures can appear to be conflicting in cases of substance abuse. Incorrect interpretation of laboratory results can multiply negative impacts on clinical outcomes and may lead to patient harm or death. This report introduces the complex nature involved in understanding and interpreting urine drug testing (UDT) results in pain patients who are prescribed opioid medications. Laboratory testing examples of UDT results are provided to illustrate the sometimes discordant nature of UDT interpretation. This case study describes one method of approaching cases where laboratory result interpretation in pain clinic patients is essential for medical treatment and management. The case presented in this manuscript illustrates a reconciliation of an opiate positive immunoassay result in a patient who was prescribed only OxyContin and Wellbutrin after traumatic amputations.

Highly sensitive capillary electrophoresis-mass spectrometry for rapid screening and accurate quantitation of drugs of abuse in urine.

The combination of capillary electrophoresis (CE) and mass spectrometry (MS) is particularly well adapted to bioanalysis due to its high separation efficiency, selectivity, and sensitivity; its short analytical time; and its low solvent and sample consumption. For clinical and forensic toxicology, a two-step analysis is usually performed: first, a screening step for compound identification, and second, confirmation and/or accurate quantitation in cases of presumed positive results. In this study, a fast and sensitive CE-MS workflow was developed for the screening and quantitation of drugs of abuse in urine samples. A CE with a time-of-flight MS (CE-TOF/MS) screening method was developed using a simple urine dilution and on-line sample preconcentration with pH-mediated stacking. The sample stacking allowed for a high loading capacity (20.5% of the capillary length), leading to limits of detection as low as 2 ng mL(-1) for drugs of abuse. Compound quantitation of positive samples was performed by CE-MS/MS with a triple quadrupole MS equipped with an adapted triple-tube sprayer and an electrospray ionization (ESI) source. The CE-ESI-MS/MS method was validated for two model compounds, cocaine (COC) and methadone (MTD), according to the Guidance of the Food and Drug Administration. The quantitative performance was evaluated for selectivity, response function, the lower limit of quantitation, trueness, precision, and accuracy. COC and MTD detection in urine samples was determined to be accurate over the range of 10-1000 ng mL(-1) and 21-1000 ng mL(-1), respectively.

Extraction and determination of opium alkaloids in urine samples using dispersive liquid-liquid microextraction followed by high-performance liquid chromatography.

A simple, rapid and sensitive method based on dispersive liquid-liquid microextraction (DLLME) combined with high-performance liquid chromatography-ultraviolet detection (HPLC-UV) was used to determine opium alkaloids in urine samples. Some effective parameters on extraction were studied and optimized. Under the optimum conditions, enrichment factors and recoveries for different opiates are in the range of 63.0-104.5 and 31.5-52.2%, respectively. The calibration graphs are linear in the range of 0.50-500 µg L(-1) and limit of detections (LODs) are in the range of 0.2-10 µg L(-1). The relative standard deviations (RSDs) for 200 µg L(-1) of morphine, codeine and thebaine, 5.0 µg L(-1) of papaverine and 10.0 µg L(-1) of noscapine in diluted urine sample are in the range of 2.8-6.1% (n=7). The relative recoveries of urine samples spiked with alkaloids are 84.3-106.0%. The obtained results show that DLLME combined with HPLC-UV is a fast and simple method for the determination of opium alkaloids in urine samples.