Prolonged Ketamine and Norketamine Excretion Profiles in Urine After Chronic Use: A Case Series.

PURPOSE/BACKGROUND: Ketamine (K) is used as a party drug with hallucinogenic properties with a half-life of about 2.5 hours. Data are available with respect to the detection window (ie, when a person is still tested positive for the drug and/or metabolite after use) of K after single use. Nevertheless, no data are available with respect to the detection window of K in urine after chronic use. METHODS/PROCEDURES: This retrospective case series describes 7 patients with K dependency as their main addiction who have been admitted to an addiction center for K detoxification. Their abstinence-oriented care involved routine urinary screening of K and its metabolites, as well as traditional drugs of abuse, such as cocaine and cannabinoids. FINDINGS/RESULTS: Urine samples remained positive for all the cases identified after 22 to 96 days. A peak detection period of 61, 40, and 96 days for K, norketamine, and dehydronorketamine, respectively, measured using liquid chromatography-tandem mass spectrometry at a cutoff concentration of 1.0 ng/mL, is defined. The K/norketamine and K/dehydronorketamine ratios varied over time between 0.33 and 3.06, and 0.01 and 0.36 for all patients, respectively, implying a large interindividual variation in K metabolism. IMPLICATIONS/CONCLUSIONS: Ketamine and its metabolites have a prolonged excretion profile in urine, which requires frequent measurements (at least weekly) to guide abstinence treatment. Further research is needed to develop an algorithm that can differentiate new K use from residual urinary K excretion in urine of chronic daily users.

A Fast and Validated High Throughput Bar Adsorptive Microextraction (HT-BAµE) Method for the Determination of Ketamine and Norketamine in Urine Samples.

We developed, optimized and validated a fast analytical cycle using high throughput bar adsorptive microextraction and microliquid desorption (HT-BAµE-µLD) for the extraction and desorption of ketamine and norketamine in up to 100 urine samples simultaneously, resulting in an assay time of only 0.45 min/sample. The identification and quantification were carried out using large volume injection-gas chromatography-mass spectrometry operating in the selected ion monitoring mode (LVI-GC-MS(SIM)). Several parameters that could influencing HT-BAµE were assayed and optimized in order to maximize the recovery yields of ketamine and norketamine from aqueous media. These included sorbent selectivity, desorption solvent and time, as well as shaking rate, microextraction time, matrix pH, ionic strength and polarity. Under optimized experimental conditions, suitable sensitivity (1.0 µg L-1), accuracy (85.5-112.1%), precision (≤15%) and recovery yields (84.9-105.0%) were achieved. Compared to existing methods, the herein described analytical cycle is much faster, environmentally friendly and cost-effective for the quantification of ketamine and norketamine in urine samples. To our knowledge, this is the first work that employs a high throughput based microextraction approach for the simultaneous extraction and subsequent desorption of ketamine and norketamine in up to 100 urine samples simultaneously.

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.

Enantioselective capillary electrophoresis provides insight into the phase II metabolism of ketamine and its metabolites in vivo and in vitro.

Glucuronidation catalyzed by uridine-5'-diphospho-glucuronosyl-transferases (UGTs) is the most important reaction in phase II metabolism of drugs and other compounds. O-glucuronidation is more common than N-glucuronidation. The anesthetic, analgesic and antidepressive drug ketamine is metabolized in phase I by cytochrome P450 enzymes to norketamine, hydroxynorketamine (HNK) diastereomers and dehydronorketamine (DHNK). Equine urine samples collected two hours after ketamine injection were treated with ß-glucuronidase and analyzed with three enantioselective capillary electrophoresis assays. Concentrations of HNK diastereomers and norketamine were significantly higher in comparison to untreated urine and an increase of ketamine and DHNK levels was found in selected but not all samples. This suggests that O-glucuronides of HNK and N-glucuronides of the other compounds are formed in equines. N-glucuronidation of norketamine was studied in vitro with liver microsomes of different species and the single human enzyme UGT1A4. With equine liver microsomes (ELM) a stereoselective N-glucuronidation of norketamine was found that compares well to the results obtained with urines collected after ketamine administration. No reaction was observed with canine liver microsomes, human liver microsomes and UGT1A4. Incubation of ketamine and DHNK with ELM did not reveal any glucuronidation. Enantioselective CE is suitable to provide insight into the phase II metabolism of ketamine and its metabolites.

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.

False positive ketamine urine immunoassay screen result induced by quetiapine: A case report.

Ketamine immunoassay urine drug screen (UDS) is commonly used in Taiwan. However, there was limited report about possible drug which may cause false positive results in ketamine screen test. We report two cases who used quetiapine showed positive in ketamine urine immunoassay screen initially, and found to be false positive in confirmation test. Clinicians should be aware of the false positive result of ketamine UDS caused by currently used medication.

Effects of gender on ketamine-induced conditioned placed preference and urine metabonomics.

OBJECTIVE: The aim of this study was to examine whether or not there was a gender difference in CPP (conditioned placed preference) induced by ketamine and to further explore the effect of sex on metabolic responses to ketamine inducing in SD rats. METHODS: We measured ketamine-induced conditioned place preference and ketamine-induced metabolic changes in urine by using (1)H nuclear magnetic resonance (NMR) coupled with principal component analysis (PCA), partial least squares (PLS) and orthogonal signal correction (OSC) analysis. RESULTS: In the CPP experiment, ketamine served as a positive reinforcing agent in both male and female rats, but, in particularly, the preference score of female rats was significantly higher than that of male rats. Compared with male rats, the metabolic trajectory fluctuation of the female rats was relatively larger. At the same time, different metabolites (1, 3-dimethyluric acid, cysteine-S-sulfate, glyceraldehydes, glycine, ribitol, acetoacetic acid, creatine, 3-methyladenine, hypotaurine, taurine, dimethylglycine and theobromine) between male and female rats were found. CONCLUSIONS: Female Sprague-Dawley rats were more sensitive to the ketamine-induced CPP than male rats. The fluctuation ranges of metabolic trajectory and metabolite contents in urine were both different between female and male rats. This would provide targeted suggestions for ketamine abuser, for example, men and women should take different drug withdrawal therapeutic methods.

A data-independent acquisition workflow for qualitative screening of new psychoactive substances in biological samples.

Identification of new psychoactive substances (NPS) is challenging. Developing targeted methods for their analysis can be difficult and costly due to their impermanence on the drug scene. Accurate-mass mass spectrometry (AMMS) using a quadrupole time-of-flight (QTOF) analyzer can be useful for wide-scope screening since it provides sensitive, full-spectrum MS data. Our article presents a qualitative screening workflow based on data-independent acquisition mode (all-ions MS/MS) on liquid chromatography (LC) coupled to QTOFMS for the detection and identification of NPS in biological matrices. The workflow combines and structures fundamentals of target and suspect screening data processing techniques in a structured algorithm. This allows the detection and tentative identification of NPS and their metabolites. We have applied the workflow to two actual case studies involving drug intoxications where we detected and confirmed the parent compounds ketamine, 25B-NBOMe, 25C-NBOMe, and several predicted phase I and II metabolites not previously reported in urine and serum samples. The screening workflow demonstrates the added value for the detection and identification of NPS in biological matrices.

Analysis of new designer drugs and common drugs of abuse in urine by a combined targeted and untargeted LC-HR-QTOFMS approach.

The development of a liquid chromatography high-resolution mass spectrometry quadrupole-time-of-flight (LC-HRMS-QTOF) method for the analysis of new stimulant designer drugs (e.g. phenethylamine, amphetamine, cathinone and piperazine derivatives) and common drugs of abuse (e.g. ketamine and ritalinic acid) in urine is reported. Sample preparation was carried out by a fast and convenient salting-out liquid-liquid extraction (SALLE) procedure. The data was generated by a preferred target list combined with untargeted data-dependent acquisition recording additional sample information (i.e. not listed metabolites of target compounds or not database-stored drugs). The identification is realised by a fully automated data extraction algorithm, taking into account accurate mass spectra, fragment masses and retention times. Method validation comprised selectivity, linearity, accuracy, stability, determination of the limit of detection (LOD) and limit of quantification (LOQ) and evaluation of matrix effects and recoveries for a total set of 39 compounds. Acceptable quantitative results were obtained for 35 of the 39 analytes. Exemplarily, application of the additional untargeted data-dependent acquisition mode enabled the identification of metabolites of the preferred target list compounds ketamine and methylenedioxypyrovalerone (MDPV) without use of reference standards. Therefore, improvement of the database is feasible with every positive library hit. The approach presented here provides a very useful tool for the combined targeted and untargeted analysis of drugs of abuse in biological matrices such as urine.

Long-term ketamine abuse induces cystitis in rats by impairing the bladder epithelial barrier.

Long-term ketamine abuse is known to affect the lower urinary tract and produce symptoms of cystitis. However, the pathophysiology and causative mechanism of the changes in bladder function remain unclear. The present study aimed to investigate the existence of ketamine-induced cystitis in a rat model and characterize the underlining mechanisms. Rats were assigned to blank control, normal saline (NS), low-dose ketamine (LK, 5 mg/kg), and high-dose ketamine (HK, 50 mg/kg) groups. The two experimental groups received ketamine hydrochloride daily for 16 weeks. All rats were housed individually for assessment of urinary frequency and urine volume. Urinary biomarkers were measured at different time points. Rat bladders were excised for histopathology, immunohistochemistry, and western blot analysis. Ketamine-treated rats had increased urinary frequency compared to NS-treated rats at Week 16. Urinary nitric oxide and antiproliferative factor levels were increased in ketamine-treated rats within the first 30 h after administration. After long-term ketamine administration, urinary glycoprotein GP51 and potassium levels were decreased in the HK and LK groups compared to the NS group. Ketamine-treated rats showed thickened bladder epithelial layer, increased expression of inducible nitric oxide synthase and occludin, and decreased expression of zonula occludens-1 in the bladder wall. Ketamine, or its urinary metabolites, disrupted the proliferation of bladder epithelial cells, resulting in defected bladder epithelial barrier. Subsequent leakage of urinary potassium causes a stress response in the bladder and provokes cystitis.

Liquid-phase microextraction based on two immiscible organic solvents followed by gas chromatography with mass spectrometry as an efficient method for the preconcentration and determination of cocaine, ketamine, and lidocaine in human urine samples.

A new type of liquid-phase microextraction based on two immiscible organic solvents was optimized and validated for the quantification of lidocaine, ketamine, and cocaine in human urine samples. A hollow-fiber based microextraction technique followed by gas chromatography coupled with mass spectrometry detection was used to reduce matrix interferences and improve limits of detection. The analytes were extracted from aqueous sample with pH 11.0, into a thin layer of organic solvent (n-dodecane) sustained in the pores of a hollow fiber, and then into a second organic acceptor (acetonitrile) located inside the lumen of the hollow fiber. With the application of optimized values, good linearity was obtained in the range of 1-500 µg/L for lidocaine and ketamine and 2-500 µg/L for cocaine with the determination coefficient values (r(2) ) >0.9943. The preconcentration factors and limits of detection (S/N > 3) were 250-350 and 0.01-0.05 µg/L, respectively. Intra and interassay precision values were <7.3 and 9.3%, respectively. The method was successfully applied for the determination and quantification of target analytes in human urine samples.

Rapid detection and quantitation of ketamine and norketamine in urine and oral fluid by wooden-tip electrospray ionization mass spectrometry.

Drug analysis is an indispensable task in controlling drug abuse, which is a serious problem worldwide nowadays. In this study, we report a simple and rapid approach for detection and quantitation of drugs-of-abuse in urine and oral fluid by wooden-tip electrospray ionization mass spectrometry (WT-ESI-MS). We demonstrated that ketamine, one of the most common abused drugs, and its major metabolite, norketamine, in raw urine and oral fluid could be readily detected and quantified by WT-ESI-MS with only little sample preparation and no chromatographic separation, and the analytical performances, including the linear range, accuracy, precision, LOD and LOQ, were well acceptable for analysis of real samples.

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.

Rapid analysis of abused drugs using nanostructured silicon surface assisted laser desorption/ionization mass spectrometry.

This study developed a rapid, sensitive, and matrix-free method for the determination of amphetamine (AMP), methamphetamine (MA), codeine (COD), morphine (MOR), and ketamine (KET) using nanostructured silicon surface assisted laser desorption/ionization mass spectrometry (nSi-MS). The nanostructured silicon (nSi) chip used in this study was created by employing the metal-assisted etching process. Drug standard tests were applied to the nSi chip platform to evaluate the nSi-MS performance, including detection sensitivity, limit of detection, linearity, and repeatability. Real urine samples obtained from drug addict detainees were directly applied to the nSi chip for drug analysis. By observing the nSi-MS spectra, the target drug peaks can be identified; and an antibody pull-down assay was performed to confirm the specificity of the detected targets. nSi-MS drug quantification was assayed, yielding comparable results with those from using the GC-MS approach. The advantages of applying nSi-MS to analyze AMP, MA, COD, MOR, and KET in the urine of addicts are simple, extremely small urine volumes (∼10 µL), and a fast analysis procedure (<15 minutes).

Simultaneous Quantitation of Seven Phenethylamine-Type Drugs in Forensic Blood and Urine Samples by UHPLC-MS-MS.

Abuse of new psychoactive substances (NPS) has become a health and social issue of global concern. p-Methoxyamphetamine (PMA)/p-methoxymethamphetamine (PMMA) with fluoro- or chloro-derivatives of amphetamine and methamphetamine were among the most common drugs found in specimens from fatal cases in Taiwan during the January 2011 to December 2018 period. A liquid-liquid extraction sample preparation protocol with highly sensitive ultra-high performance liquid chromatography-tandem mass spectrometry approach was developed for the simultaneous analysis of seven phenethylamine-type drugs-PMA, PMMA, p-methoxyethylamphetamine, 4-fluoroamphetamine (4-FA), 4-fluoromethamphetamine (4-FMA), 4-chloroamphetamine (4-CA) and 4-chloromethamphetamine (4-CMA)-in postmortem blood and urine specimens. Separation by liquid chromatography was performed by Agilent Zorbax SB-Aq column. Tandem mass spectrometry was operated in Agilent Jet Stream Technology electrospray ionization in positive-ion multiple reaction monitoring mode. An analytical methodology was evaluated using drug-free blood and urine after fortification with 100-2,000 ng/mL of the seven target analytes. Average extraction recoveries were >80%; slightly higher ion suppression was observed for PMA and 4-CA; intra-/inter-day precision (% coefficient of variation) and accuracy were in the ranges of 0.52-12.3% and 85-110%, respectively. Limit of detection and lower limit of quantitation for these seven analytes were both in the 0.5-5 ng/mL range. Interference and carryover were not significant. This relatively simple methodology was found effective and reliable for routine identification and quantitation of these seven analytes in postmortem and antemortem blood and urine specimens received in 2018. Analytical data obtained from these actual cases indicated the following: (i) compared to findings reported during the 2007-2011 period, the use of substituted phenethylamine-type drugs decreased in 2018; (ii) ketamine and 7-aminonimetazepam (the main metabolite of nimetazepam) were the most common co-ingested substances in specimens containing PMA/PMMA, 4-FA/4-FMA, or 4-CA/4-CMA; and (iii) in drug fatalities, the concentration of PMA was significantly higher than the concentration of PMMA in both urine and blood, while the reverse was true in urine specimens from antemortem cases.

Determination of eight illegal drugs in human urine by combination of magnetic solid-phase extraction with capillary zone electrophoresis.

Using magnetite/silica/poly(methacrylic acid-co-ethylene glycol dimethacrylate) (Fe(3)O(4)/SiO(2)/poly(MAA-co-EDMA)) magnetic microspheres, a rapid and high-throughput magnetic solid-phase extraction coupled with capillary zone electrophoresis (MSPE-CZE) method was developed for the determination of illegal drugs (ketamine, amphetamines, opiates, and metabolites). The MSPE of target analytes could be completed within 2 min, and the eight target analytes could be baseline separated within 15 min by CZE with 30 mM phosphate buffer solution (PBS, pH 2.0) containing 15% v/v ACN as background electrolyte. Furthermore, hydrodynamic injection with field-amplified sample stacking (FASS) was employed to enhance the sensitivity of this MSPE-CZE method. Under such optimal conditions, the limits of detection for the eight target analytes ranged from 0.015 to 0.105 µg/mL. The application feasibility of MSPE-CZE in illegal drugs monitoring was demonstrated by analyzing urine samples, and the recoveries of target drugs for the spiked sample ranging from 85.4 to 110.1%. The method reproducibility was tested by evaluating the intra- and interday precisions, and relative standard deviations of <10.3 and 12.4%, respectively, were obtained. To increase throughput of the analysis, a home-made MSPE array that has potential application to the treatment of 96 samples simultaneously was used.

Extraction of ketamine from urine using a miniature silica monolithic cartridge followed by quantification with liquid chromatography tandem mass spectrometry (LC-MS/MS).

The high surface area monolith with reactive hydroxyl group on its surface enables it to function as a miniature solid-phase extraction (SPE) cartridge in size of 1 cm in diameter and 0.5 cm in length. The prepared silica monolith was characterized by Brunauer-Emmett-Teller method, scanning electron microscopy, X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy. Ketamine was selected as model analyte to validate the extraction efficiency of the prepared cartridge. The extracted ketamine from urine sample was quantitated by liquid chromatography tandem mass spectrometry (LC-MS/MS) using positive electrospray ionization. The limit of detection and quantification for ketamine was found to be 0.5 and 1.6 ng/mL, respectively. The analysis exhibited linearity in the range of 10-500 ng/mL with coefficient of correlation >0.99. The recovery was found to be in the range of 89-107% with relative standard deviation (RSD) less than 10%. The prepared cartridge was found robust in extracting ketamine efficiently and repeatedly without any significant deterioration in its performance. Moreover, the batch-to-batch variations in the performance of the prepared cartridges in terms of % ion suppression of the extracts and recoveries of samples were small, suggesting the consistency in the properties of the monolith.

Magnetic solid-phase extraction using magnetic hypercrosslinked polymer for rapid determination of illegal drugs in urine.

A novel magnetic material Fe(3)O(4)/SiO(2)/P(MAA-co-VBC-co-DVB) was prepared via the hypercrosslinking of its precursor which was produced via precipitation polymerization of methacrylic acid (MAA), vinylbenzyl chloride (VBC), and divinylbenzene (DVB) in the presence of Fe(3)O(4)/SiO(2) submicrospheres with the surface containing abundant reactive double bonds. The resultant sorbent was characterized by scan electron microscopy, N(2) adsorption, and Fourier transform infrared spectroscopy. It was found that this material had remarkable features such as large surface area (500 m(2)/g) and pore volume (0.32 cm(3)/g), as well as desirable chemical composition (including hydrophobic and ion-exchange moieties). Taking advantages of the Fe(3)O(4)/SiO(2)/P(MAA-co-VBC-co-DVB), a magnetic SPE (MSPE) coupled with capillary electrophoresis (CE) method was developed for the determination of illegal drugs in urine samples. The extraction time could be clearly shortened up to 3 min. The recoveries of these drug compounds were in the range of 84.0-123% with relative standard deviations ranging between 1.7 and 10.5%; the limit of detection was in the range of 4.0-6.0 µg/L. The proposed method is simple, effective, and low-cost, and provides an accurate and sensitive detection platform for abused drug analysis.

Association of urinary ketamine and APOA1 levels with bladder dysfunction in ketamine abusers revealed via proteomics and targeted metabolite analyses.

Chronic ketamine abuse is associated with bladder dysfunction and cystitis. However, the effects of ketamine abuse on the urinary proteome profile and the correlations among urinary proteins, urinary ketamine (and metabolites) and clinicopathological features of ketamine-induced bladder dysfunction remain to be established. Here, we recruited 56 ketamine abusers (KA) and 40 age-matched healthy controls (HC) and applied the iTRAQ-based proteomics approach to unravel quantitative changes in the urine proteome profile between the two groups. Many of the differentially regulated proteins are involved in the complement and coagulation cascades and/or fibrotic disease. Among them, a significant increase in APOA1 levels in KA relative to control samples (392.1 ± 59.9 ng/ml vs. 13.7 ± 32.6 ng/ml, p < 0.0001) was detected via ELISA. Moreover, urinary ketamine, norketamine and dehydronorketamine contents (measured via LC-SRM-MS) were found to be positively correlated with overactive bladder syndrome score (OABSS) and APOA1 levels with urinary RBC, WBC, OABSS and numeric pain rating scale in KA. Collectively, our results may aid in developing new molecular tool(s) for management of ketamine-induced bladder dysfunction. Moreover, information regarding the differentially regulated proteins in urine of KA provides valuable clues to establish the molecular mechanisms underlying ketamine-induced cystitis.

On-line microdialysis coupled solid-phase extraction to decrease matrix interference in the HPLC analysis of urinary ketamine and its metabolites.

A microdialysis sampling (MDS) on-line SPE (MDS/SPE) has been applied to redeem the detection after dilution to decrease matrix interference in the analysis of ketamine (K) and its two main metabolites, norketamine (NK) and dehydronorketamine (DHNK) in urine by HPLC. After being filtrated, diluted and adjusting the pH, K and its metabolites in the diluted sample solution were collected through MDS and then trapped on an on-line SPE for HPLC analysis. The optimal conditions for MDS/SPE were investigated and then applied to real sample analysis. Experimental results indicated that the MDS/SPE by using regenerated cellulose hollow fiber (8-cm length) and 1 mM sulfuric acid as the perfusate at 20 microL/min flow-rate to collect analytes from 100-fold diluted urine sample (20 mL at pH 6.0), and then having been trapped in octadecyl-modified silica phase SPE for 30 min, offered the optimum efficiency. The concentration levels of 41, 42 and 28% (m/m) for K, NK and DHNK, respectively, in urine were redeemed for determination. The detection limits were 0.38, 0.33 and 0.34 ng/mL (in 100-fold diluted sample) for K, NK and DHNK, respectively. The method provides a very simple, inexpensive and eco-friendly procedure to determine K, NK and DHNK in urine.