Evaluation of the Urine Drug Abuse Screening Tests.

BACKGROUND: Substance use is an important public health problem and increasing all over the world. Different methods have been defined for drug abuse testing in medical laboratories. We aimed to compare two urine drug screening methods with liquid chromatography-tandem mass spectrometry (LC-MS/MS). METHODS: A total of 102 patients' urine samples were analyzed by test dip card and EMIT (enzyme multiplied im-munoassay technique). Randomly selected samples (n = 51; 50%) were also analyzed by LC-MS/MS as the reference method. RESULTS: The drug results of all patients analyzed with the test card and EMIT were compatible. Nine of 51 samples (18%) were negative according to all methods. The sensitivity and specificity percentages of AMP, COC, MDMA, OPI/MOP, and THC using test card were 70/96, 100/100, 47/100, 50/100, and 80/85, respectively. Similarly, the sensitivity and specificity percentages of AMP, COC, MDMA, OPI/MOP, and THC using EMIT were 76/97, 100/100, 57/100, 56/100, and 76/91, respectively. CONCLUSIONS: The performances of two immunochemical methods were similar for AMP, BZO, COC, MDMA, OPI/MOP, and THC whereas lower than LCMS/MS for AMP, MDMA, OPI/MOP, and THC. A sample that is positive according to any immunochemical method should be confirmed by definitive techniques such as LC-MS/MS.

Optimization of enantioselective high-performance liquid chromatography-tandem mass spectrometry method for the quantitative determination of 3,4-methylenedioxy-methamphetamine (MDMA) and its phase-1 metabolites in human biological fluids.

Recently we published in this journal an enantioselective high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantitative determination of 3,4-methylenedioxymethamphetamine (MDMA) and its major phase-1 metabolites, 4-hydroxy-3-methoxyamphetamine (HMA), 4-hydroxy-3-methoxymethamphetamine (HMMA) and 3,4-methylenedioxyamphetamine (MDA) in human plasma, sweat, oral fluid and urine. Since we did not achieve simultaneous enantioseparation of all 4 compounds with a single chiral column, two amylose-based chiral columns were used alternatively. Further optimization of the mobile phase in the present study enabled baseline separation of all four pairs of enantiomers on a single Lux AMP column. In addition, by optimization of the column dimension and applied flow-rate it became possible to complete the separation within 6 minutes. These new methods were applied to the analysis of human plasma, oral fluid and urine. While results on the concentration of MDMA and its metabolites in various biological fluids were reported in our recent publication, in the present study an attempt was made to hydrolyze glucuronides in urine samples by using alternatively, hydrochloric acid or glucuronidase and to evaluate the effect of hydrolysis on the concentration and enantiomeric distribution of hydroxy metabolites of MDMA such as HMA and HMMA.

Ketamine detection in urine samples from patients poisoned by recreational drugs: epidemiologic, clinical, and toxicologic profiles. / Detección de ketamina en pacientes intoxicados por drogas recreativas: perfil epidemiológico, clínico y toxicológico.

OBJECTIVES: To describe the epidemiologic, clinical, and toxicologic profiles of patients who used recreational ketamine and experienced acute poisoning. MATERIAL AND METHODS: Retrospective observational study of patients attended by several emergency medical services in the Balearic Islands for analytically confirmed acute poisoning after using ketamine between January 2016 and December 2020. Urine samples were analyzed by immunoassay and combined gas chromatography and mass spectrometry. RESULTS: One hundred twenty-two patients were studied. The mean (SD) age was 26.7 (6.5) years. The majority were men (77.9%) and not residents of the Balearic Islands (74.6%). Poisoning cases occurred mainly in the summer and in the island of Ibiza (84.4%). Ketamine use was declared by the patient or clinically suspected in 40.2%. The most common clinical signs were tachycardia (43.4%), hypertension (28.7%), mydriasis (27.0%), altered consciousness (25.4%), agitation/aggressiveness (25.4%), and hypothermia (21.3%). Seven patients (5.73%) required admission to the intensive care unit. The drugs most often detected along with ketamine were cocaine, in 93.4%, and 3,4-methylenedioxymethamphetamine (MDMA), in 78.7%. Multiple-drug use combining ketamine, cocaine, and MDMA, or on occasion additional substances, was detected in 98.4%. CONCLUSION: Detection of ketamine in urine samples from patients poisoned by recreational drugs is associated with a characteristic profile: young men who are not residents of the Balearic Islands, who attend electronic music concerts, and who have taken multiple drugs. A substantial percentage of such patients are unaware of drug intake.

OBJETIVO: Identificar el perfil epidemiológico, clínico y toxicológico de los pacientes consumidores de ketamina en el contexto de una intoxicación aguda por drogas recreativas. METODO: Estudio observacional retrospectivo en pacientes atendidos en varios servicios de urgencias (SU) en Baleares por intoxicaciones agudas por drogas recreativas con exposición a ketamina confirmada analíticamente, entre enero de 2016 y diciembre de 2020. El análisis toxicológico en muestras de orina se realizó mediante inmunoensayo y cromatografía de gases acoplada a espectrometría de masas. RESULTADOS: Se incluyeron 122 pacientes. La edad media fue de 26,7 (DE 6,5) años. La mayoría eran hombres (77,9%) y no residentes en las Islas Baleares (74,6%). Los casos se detectaron mayoritariamente en verano y en Ibiza (84,4%). El uso de ketamina solo fue declarado por el paciente o fue clínicamente sospechado por el médico en el 40,2%. Los signos clínicos más frecuentes fueron taquicardia (43,4%), hipertensión (28,7%), midriasis (27,0%), disminución de la consciencia (25,4%), agitación/agresividad (25,4%) e hipotermia (21,3%). Siete pacientes (5,7%) requirieron ingreso en la unidad de cuidados intensivos (UCI). La cocaína (93,4%) y la 3,4-metilendioximetanfetamina (MDMA) (78,7%) fueron las drogas más detectadas junto con la ketamina. El policonsumo fue habitual (98,4%), combinando ketamina, cocaína y MDMA, en algunos casos asociado a otras sustancias. CONCLUSIONES: La detección de ketamina en intoxicaciones por drogas recreativas se asocia a consumidores con un perfil característico (varones jóvenes, no residentes, asistentes a eventos de música electrónica y policonsumo) y un alto porcentaje desconocen de este consumo.

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.

Ambient mass spectrometry for rapid diagnosis of psychoactive drugs overdose in an unstable patient.

A 25-year-old man suffered from consciousness change was sent to our emergency department by friends who reported that they were not sure what had happened to him. Physical examination revealed bilateral pupils dilatation, lethargy, slurred speech, and ataxia. Computer-aided tomographic scan of the brain revealed no definite evidence of intracranial lesions. Routine laboratory tests revealed total physiological turmoil. Despite immediate commencement of aggressive treatment, the patient's condition deteriorated long before the traditional drug screen provided an answer for the identities of the multiple drugs overdose. It ended up with the need for cardiopulmonary resuscitation, but in vain. At the end of the tragic event, under the suggestion of a colleague, a portion of the patient's urine specimen was sent to our university esoteric laboratory for rapid analysis by means of a newly-developed thermal desorption-electrospray ionization-mass spectrometry. Ketamine, 3,4-methylenedioxymethamphetamine, and 3,4-methylenedioxyamphetamine were identified in the urine sample within 30s. Conventional toxicological testing techniques like gas chromatography-mass spectrometry or liquid chromatography-mass spectrometry are currently used for identifying abused drugs. One concern is their time-consuming sample pretreatment which leads to relatively low efficiency in terms of turnaround time for revealing the identity of the consumed drugs particularly when the patients are severely overdosed. We learned a lesson from this case that a more efficient toxicological identification technique is essential to expedite the process of emergency care when the patients are so heavily overdosed that they are under critical life-threatening conditions.

Recreational drug use at a major music festival: trend analysis of anonymised pooled urine.

OBJECTIVE: The spread of new psychoactive substances (NPS) has expanded rapidly in the last decade. The complexity of the pharmacological effects of NPS challenges the traditional treatment guidelines, and information of the emergence of new arrivals is valuable. Our knowledge on the actual range of recreational drugs used and NPS available in Denmark is limited as identification is possible only when consumers become patients in the healthcare system or through drug seizures. We aimed to detect classical recreational drugs and NPS in the urine of music festival attendees and evaluate if the use of NPS could have been predicted by comparing study data with drug seizure data from the previous year published by European and Danish health authorities. METHODS: In a cross-sectional study, 44 urine samples were collected from three urinals at Roskilde Festival 2016-the largest Danish music festival. Two urinals were placed at music stages with late-night concerts, and one urinal was placed at a camp site. Samples were prepared using enzymatic hydrolysis followed by cationic and anionic solid phase extraction, and analysed using ultra performance liquid chromatography-high-resolution time-of-flight mass spectrometry (UPLC-HR-TOF-MS). Data were processed using an in-house library of 467 target substances, including legal and illegal drugs and metabolites. Urine drug-screening immunoassays were also evaluated and results were compared to UPLC-HR-TOF-MS results. RESULTS: In total, 77 drugs, including metabolites, were qualitatively identified in the 44 urine samples. The recreational drugs identified were amphetamine (n = 30), cocaine (n = 44), MDA (n = 40), MDMA (n = 44), THC-COOH (n = 19) and ketamine (n = 17). No NPS were identified. Sample testing using the urine drug-screening immunoassays showed presence of cocaine (n = 27), methamphetamine/MDMA (n = 4), THC (n = 7), "Spice" (n = 7) and methylphenidate (n = 1). These discrepancies might be caused by differences in cut-off values between the analytical methods, limited specificity or cross-reactivity of the urine drug-screening immunoassays compared to UPLC-HR-TOFMS results. CONCLUSION: Widespread uses of classical recreational drugs were identified in pooled urine samples. The prevalence of NPS was not as comprehensive as expected based on the European and Danish health authorities reports on illegal drugs. Urine drug-screening immunoassays results are advised to be confirmed by chromatographic bioanalysis.

Dynamic surface-enhanced Raman spectroscopy and Chemometric methods for fast detection and intelligent identification of methamphetamine and 3, 4-Methylenedioxy methamphetamine in human urine.

Conventional Surface-Enhanced Raman Spectroscopy (SERS) for fast detection of drugs in urine on the portable Raman spectrometer remains challenges because of low sensitivity and unreliable Raman signal, and spectra process with manual intervention. Here, we develop a novel detection method of drugs in urine using chemometric methods and dynamic SERS (D-SERS) with mPEG-SH coated gold nanorods (GNRs). D-SERS combined with the uniform GNRs can obtain giant enhancement, and the signal is also of high reproducibility. On the basis of the above advantages, we obtained the spectra of urine, urine with methamphetamine (MAMP), urine with 3, 4-Methylenedioxy Methamphetamine (MDMA) using D-SERS. Simultaneously, some chemometric methods were introduced for the intelligent and automatic analysis of spectra. Firstly, the spectra at the critical state were selected through using K-means. Then, the spectra were proposed by random forest (RF) with feature selection and principal component analysis (PCA) to develop the recognition model. And the identification accuracy of model were 100%, 98.7% and 96.7%, respectively. To validate the effect in practical issue further, the drug abusers'urine samples with 0.4, 3, 30ppm MAMP were detected using D-SERS and identified by the classification model. The high recognition accuracy of >92.0% can meet the demand of practical application. Additionally, the parameter optimization of RF classification model was simple. Compared with the general laboratory method, the detection process of urine's spectra using D-SERS only need 2 mins and 2µL samples volume, and the identification of spectra based on chemometric methods can be finish in seconds. It is verified that the proposed approach can provide the accurate, convenient and rapid detection of drugs in urine.

Cross-reactivity of selected benzofurans with commercial amphetamine and ecstasy immunoassays in urine.

AIM: The aim of this study was to perform a cross-reactivity investigation of six benzofurans with immunoassays (IAs) screening tests for amphetamines and ecstasy in urine samples. METHODS: The following benzofuranes were investigated: 5-(2-Methylaminopropyl)Benzofuran (5-MAPB), 5-(2-methylaminopropyl)-2,3-dihydrobenzofuran (5-MAPDB), 5-(2-Aminopropyl)-Benzofuran (5-APB), 5-(2-Aminopropyl)-2,3-dihydrobenzofuran (5-APDB), 5-(2-Ethylaminopropyl)Benzofuran (5-EAPB) and 5-(2-Aminoethyl)-2,3-dihydrobenzofuran (5-AEDB). The study was performed with urine-free spiked samples and authentic urine samples using eight different IAs for amphetamines and ecstasy. Results: All evaluated benzofurans showed cross-reactivity in some of the IAs tested, except for 5-AEDB. Urine samples of an intoxication case involving 5-MAPB, 5-APB and 5-EAPB were also positives in the IAs tested. CONCLUSION: There is an important variability in the cross-reactivity of the IAs for amphetamine and ecstasy caused by benzofurans depending on the immunoassay employed and the tested compounds.

Commercial herbal medicines used as African traditional medicines: Ngoma Herbal Tonic Immune Booster interferes with a rapid urine drug screening test.

BACKGROUND: The prevalent use of African traditional medicine by the general public has been reported. With commercialisation and marketing, some of the herbal medicines (HMs) used are readily available over the counter, most of them promoted as immune boosters. These commercial HMs have not been taken through clinical trials and other tests that would validate their composition and safety, and other properties such as their effect on laboratory diagnostic tests. OBJECTIVE: To investigate the cross-reactivity of selected HMs with commonly tested drugs of abuse (DoA) using a qualitative rapid urinalysis assay. METHODS: The six HMs selected were bought from local pharmacies. A rapid urinalysis screening test was performed with the Instant View Multi-Drug of Abuse Test kit from Labstix Diagnostics. Drug-free urine (DFU) was pooled from samples donated by healthy volunteers. Urine samples that had tested positive for DoA were obtained from a pharmacology laboratory. Aliquots of the urine samples were spiked with the HMs in neat and diluted form, and tested at various time intervals. RESULTS: The results for the DFU samples spiked with the HMs remained negative. There were no significant changes in pH or specific gravity of the samples. The results of samples that had tested positive for tetrahydrocannabinol (THC) were not altered by five of the HMs when spiked at 40% v/v. The HM Ngoma Herbal Tonic Immune Booster caused false-negative results for the THC test. CONCLUSION: An important finding is that the herbal mixture Ngoma Herbal Tonic Immune Booster caused false-negative results for the cannabinoid screening test. It adds to the list of substances that may be potential adulterants of urine for screening tests.

Screening for illicit drugs in pooled human urine and urinated soil samples and studies on the stability of urinary excretion products of cocaine, MDMA, and MDEA in wastewater by hyphenated mass spectrometry techniques.

Monitoring population drug use through wastewater-based epidemiology (WBE) is a useful method to quantitatively follow trends and estimate total drug consumption in communities. Concentrations of drug biomarkers might be low in wastewater due to dilution; and therefore analysis of pooled urine (PU) is useful to detect consumed drugs and identify targets of illicit drugs use. The aims of the study were (1) to screen PU and urinated soil (US) samples collected at festivals for illicit drug excretion products using hyphenated techniques; (2) to develop and validate a hydrophilic interaction liquid chromatography - mass spectrometry / mass spectrometry (HILIC-MS/MS) method of quantifying urinary targets of identified drugs in wastewater; and (3) to conduct a 24 h stability study, using PU and US to better reflect the chemical environment for targets in wastewater. Cocaine (COC) and ecstasy-like compounds were the most frequently detected illicit drugs; an analytical method was developed to quantify their excretion products. Hydroxymethoxymethamphetamine (HMMA), 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), HMMA sulfate (HMMA-S), benzoylecgonine (BE), and cocaethylene (CE) had 85-102% of initial concentration after 8 h of incubation, whereas COC and ecgonine methyl ester (EME) had 74 and 67% after 8 h, respectively. HMMA showed a net increase during 24 h of incubation (107% ± 27, n = 8), possibly due to the cleavage of HMMA conjugates, and biotransformation of MDMA. The results suggest HMMA as analytical target for MDMA consumption in WBE, due to its stability in wastewater and its excretion as the main phase I metabolite of MDMA. Copyright © 2016 John Wiley & Sons, Ltd.

A Cross-Reactivity of Fenofibric Acid With MDMA DRI Assay.

BACKGROUND: Within the framework of routine fitness examinations, French Air Force military crew underwent urine testing for 3,4 methylenedioxymetamphetamine (MDMA [ecstasy]). The cross-reactivity of a dyslipidemic drug, fenofibrate, with an MDMA immunoassay was studied and confirmed on a large population sample. METHODS: A 3-year retrospective study was performed on the MDMA DRI Ecstasy Assay on the Unicel DXC 600. In the event of positive test result, a confirmatory testing was carried out by gas chromatography/mass spectrometry (GC/MS) to establish the presence of MDMA. When analysis by GC/MS did not confirm the presence of MDMA, a false-positive result was suspected and the samples were analyzed by high-performance liquid chromatography-mass spectrometry to identify a potential interfering substance. RESULTS: A total of 15,169 urine samples, from 7,803 patients, were tested for 3 years. Of the tested samples, 22 (0.15%) were positive by DRI Ecstasy Assay. None of them were positive by GC/MS. A cross-reactivity of fenofibrate's metabolite with MDMA using this assay was systematically found. CONCLUSION: Fenofibrate's interference with MDMA immunoassay was confirmed. Fenofibrate being widely prescribed, physicians had to be alerted that this treatment could lead to false-positive results.

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.

One Hundred False-Positive Amphetamine Specimens Characterized by Liquid Chromatography Time-of-Flight Mass Spectrometry.

Some amphetamine (AMP) and ecstacy (MDMA) urine immunoassay (IA) kits are prone to false-positive results due to poor specificity of the antibody. We employed two techniques, high-resolution mass spectrometry (HRMS) and an in silico structure search, to identify compounds likely to cause false-positive results. Hundred false-positive IA specimens for AMP and/or MDMA were analyzed by an Agilent 6230 time-of-flight (TOF) mass spectrometer. Separately, SciFinder (Chemical Abstracts) was used as an in silico structure search to generate a library of compounds that are known to cross-react with AMP/MDMA IAs. Chemical formulas and exact masses of 145 structures were then compared against masses identified by TOF. Compounds known to have cross-reactivity with the IAs were identified in the structure-based search. The chemical formulas and exact masses of 145 structures (of 20 chemical formulas) were compared against masses identified by TOF. Urine analysis by HRMS correlates accurate mass with chemical formulae, but provides little information regarding compound structure. Structural data of targeted antigens can be utilized to correlate HRMS-derived chemical formulas with structural analogs.

A Retrospective Analysis of Urine Drugs of Abuse Immunoassay True Positive Rates at a National Reference Laboratory.

Urine drug screens are commonly performed to identify drug use or monitor adherence to drug therapy. The purpose of this retrospective study was to evaluate the true positive and false positive rates of one of our in-house urine drug screen panels. The urine drugs of abuse panel studied consists of screening by immunoassay then positive immunoassay results were confirmed by mass spectrometry. Reagents from Syva and Microgenics were used for the immunoassay screen. The screen was performed on a Beckman AU5810 random access automated clinical analyzer. The percent of true positives for each immunoassay was determined. Agreement with previously validated GC-MS or LC-MS-MS confirmatory methods was also evaluated. There were 8,825 de-identified screening results for each of the drugs in the panel, except for alcohol (N = 2,296). The percent of samples that screened positive were: 10.0% for amphetamine/methamphetamine/3,4-methylenedioxy-methamphetamine (MDMA), 12.8% for benzodiazepines, 43.7% for opiates (including oxycodone) and 20.3% for tetrahydrocannabinol (THC). The false positive rate for amphetamine/methamphetamine was ∼14%, ∼34% for opiates (excluding oxycodone), 25% for propoxyphene and 100% for phencyclidine and MDMA immunoassays. Based on the results from this retrospective study, the true positive rate for THC drug use among adults were similar to the rate of illicit drug use in young adults from the 2013 National Survey; however, our positivity rate for cocaine was higher than the National Survey.

Portable kit for identification and detection of drugs in human urine using surface-enhanced Raman spectroscopy.

A portable kit was demonstrated for rapid and reliable surface-enhanced Raman scattering (SERS) detection of drugs in human urine. This kit contains two sealed reagent tubes, a packet of standardized SERS substrates, and a mini Raman device. A 3 min pretreatment for separating amphetamines from human urine was developed with an extraction rate of >80% examined by ultraperformance liquid chromatography (UPLC). Simultaneously, highly reproducible two-dimensional (2D) gold nanorod (GNR) arrays were assembled by the use of methoxymercaptopoly(ethylene glycol) (mPEG-SH) capping. Thirty batches of GNR arrays produced the 1001 cm(-1) intensity of methamphetamine (MA) molecules with a relative standard deviation (RSD) of 7.9%, and a 21 × 21 µm(2) area mapping on a 2D GNR array produced a statistical RSD of <10%, implying an excellent reproducibility and uniformity. The detection limit of amphetamines in human urine was at least 0.1 ppm. Moreover, the portable kit was successfully used for detecting MA, 3,4-methylenedioxymethamphetamine (MDMA), and methcathinone (MC) in 30 volunteers' urine samples with various clinical natures, and the dual-analyte detection of MA and MDMA implied a good capability of multiplex analysis. UPLC examination and the SERS recovery test clearly indicated that our pretreatment procedure was sufficient to lower the high background signals caused by complex components in urine and demonstrated the practicability and the resistance to false positives, which is a vital problem for law enforcement applications. The excellent performance of our portable kit promises a great prospective toward a rapid, reliable, and on-spot analyzer, especially for public safety and healthcare.

Fenofibric Acid Can Cause False-Positive Urine Methylenedioxymethamphetamine Immunoassay Results.

We present a false-positive result of ecstasy (3,4-methylenedioxy-NN-methylamphetamine) screening due to the therapeutic use of fenofibrate, an antihyperlipidemic drug. Our hypothesis was that the main metabolite of fenofibrate, fenofibric acid, was responsible for this cross-reactivity on a DRI(®) Ecstasy Assay, using a cut-off of 500 ng/mL. We estimated that the addition of 225 µg/mL pure fenofibric acid to blank urine would be sufficient to result in a positive DRI(®) Ecstasy Assay. The results obtained on the urine samples analyses of the patient show that the DRI(®) Ecstasy Assay resulted negative 2 days after discontinuing fenofibrate treatment, when the urine fenofibric acid concentration corrected by creatinine and determinated by gas chromatography-mass spectrometry was 20.3 µg/mg creatinine. The cross-reactivity data for fenofibric acid would seem to indicate that there was insufficient concentration of measured compound to account for the positive immunochemical results for ecstasy. This apparent discrepancy can be explained in several ways, one of them is that the ß-glucuronidase-resistent fenofibric acid isomers are responsible. This process could explain the low recovery of free fenofibric acid when we use the developed method for its quantification in urine samples. Positive results on immunoassay screening must be considered presumptive until confirmation with another method based on a different principle, preferably gas chromatography-mass spectrometry or liquid chromatography-mass spectrometry.

In-sample derivatization-solid-phase microextraction of amphetamines and ecstasy related stimulants from water and urine.

A solid-phase microextraction (SPME) method for the determination of five amphetamine type stimulants (ATSs) in water and urine samples is presented. Analytes were simultaneously derivatized with iso-butyl chloroformate (iBCF) in the aqueous sample while being extracted, improving in this way the extractability of ATSs and permitting their determination by gas chromatography-mass spectrometry (GC-MS). The SPME procedure was carefully optimized in order to achieve adequate limits of detection (LODs) for environmental concentrations. Hence, different operational parameters were considered: type of SPME coating, ionic strength, basic catalyzer and derivatizing agent amount, extraction time and temperature. The final SPME procedure consists into the extraction of 100mL of sample containing 2 g of dipotassium monohydrogen phosphate trihydrate and 100 µL of iBCF (1:1 in acetonitrile), for 40 min at 60°C with a polydimethylsiloxane-divinylbenzene (PDMS-DVB) fiber. Under these conditions, LODs in wastewater ranged from 0.4 to 2 ng L(-1), relative recoveries in the 84-114% range and relative standard deviations (RSD) lower than 15% were obtained. The application of the method to wastewater and river water samples showed the ecstasy ATS, 3,4-methylenedioxymethamphetamine (MDMA), as the most frequently detected, followed by methamphetamine, in concentrations around 20 ng L(-1). Finally, the method was downscaled and also validated with urine samples, proving its good performance with this matrix too: RSD<11%, recoveries in the 98-110% range and LODs lower than 0.1 µg L(-1).

Dispersive liquid-liquid microextraction prior to field-amplified sample injection for the sensitive analysis of 3,4-methylenedioxymethamphetamine, phencyclidine and lysergic acid diethylamide by capillary electrophoresis in human urine.

A novel capillary zone electrophoresis (CZE) with ultraviolet detection method has been developed and validated for the analysis of 3,4-methylenedioxymethamphetamine (MDMA), lysergic acid diethylamide (LSD) and phencyclidine (PCP) in human urine. The separation of these three analytes has been achieved in less than 8 min in a 72-cm effective length capillary with 50-µm internal diameter. 100 mM NaH(2)PO(4)/Na(2)HPO(4), pH 6.0 has been employed as running buffer, and the separation has been carried out at temperature and voltage of 20°C, and 25kV, respectively. The three drugs have been detected at 205 nm. Field amplified sample injection (FASI) has been employed for on-line sample preconcentration. FASI basically consists in a mismatch between the electric conductivity of the sample and that of the running buffer and it is achieved by electrokinetically injecting the sample diluted in a solvent of lower conductivity than that of the carrier electrolyte. Ultrapure water resulted to be the better sample solvent to reach the greatest enhancement factor. Injection voltage and time have been optimized to 5 kV and 20s, respectively. The irreproducibility associated to electrokinetic injection has been correcting by using tetracaine as internal standard. Dispersive liquid-liquid microextraction (DLLME) has been employed as sample treatment using experimental design and response surface methodology for the optimization of critical variables. Linear responses were found for MDMA, PCP and LSD in presence of urine matrix between 10.0 and 100 ng/mL approximately, and LODs of 1.00, 4.50, and 4.40 ng/mL were calculated for MDMA, PCP and LSD, respectively. The method has been successfully applied to the analysis of the three drugs of interest in human urine with satisfactory recovery percentages.

False-positive amphetamine/ecstasy (MDMA/3,4-methylenedioxymethamphetamine) (CEDIA) and ecstasy (MDMA/3,4-methylenedioxymethamphetamine) (DRI) test results with fenofibrate.

This case report describes a false-positive amphetamine/ecstasy [3,4-methylenedioxymethamphetamine (MDMA)] and ecstasy (MDMA) screen after therapeutic use of antihyperlipidemic drug, fenofibrate. A 60-year-old male patient was admitted to inpatient psychiatry unit with the diagnosis of alcohol dependency. He was prescribed diazepam 30 mg/day, thiamine 300 mg/day, and naltrexone 50 mg/day. He had also been using fenofibrate 267 mg/day for 3 years for hyperlipidemia and trazodone 100 mg/day for 5 months for insomnia. On routine, urine drugs-of-abuse screening amphetamine/MDMA (CEDIA) test was positive for 4 different occasions and MDMA (DRI) test was positive on 5 different occasions. Gas chromatography/mass spectrometry confirmation of the first positive 3 samples were negative for amphetamine and MDMA. After discontinuation of fenofibrate, amphetamine/MDMA, and MDMA immunoassay results turned out to be negative. Caution should be given to interpretation of amphetamine/MDMA (CEDIA) and MDMA (DRI) tests in patients taking fenofibrate. Specific confirmation with a suitable method should be used to prevent erroneous interpretations.