Development of a fully automated toxicological LC-MSn screening system in urine using online extraction with turbulent flow chromatography

[Highly sensitive determination of three kinds of amanitins in urine and plasma by ultra performance liquid chromatography-triple quadrupole mass spectrometry coupled with immunoaffinity column clean-up]

Cases of toxic mushroom poisoning occur frequently in China every year. In particular, mushrooms containing amanitins can cause acute liver damage, with high mortality rates. The symptoms of acute liver damage are experienced 9-72 h after consumption of the mushrooms. At this time, the concentration of amanitins in blood and urine is too low to be detected even by the highly sensitive ultra performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MS/MS), thus rendering clinical diagnosis and treatment difficult. To this end, a method was developed for the determination of α-amanitin, β-amanitin and γ-amanitin in urine and plasma by UPLC-MS/MS. Urine and plasma samples were extracted and cleaned up by using an immunoaffinity column. A sample of 2.00 mL urine or 1.00 mL of plasma was diluted with 8.00 mL of phosphate buffer solution (PBS) and then loaded onto the immunoaffinity column at a flow rate of 0.5-1.0 mL/min. After washing the column with 10 mL of PBS and 13 mL of water successively, the bound amanitins were eluted with 3.00 mL of methanol-acetone (1∶1, v/v). The eluent was dried under nitrogen at 55 ℃. The residue was dissolved in 100 μL of 10% (v/v) methanol aqueous solution. The amanitins in urine were concentrated 20 times, while those in plasma were concentrated 10 times. Chromatographic separation was performed on a Kinetex Biphenyl column (100 mm × 2.1 mm, 1.7 μm) with gradient elution using methanol and 0.005% (v/v) formic acid aqueous solution as mobile phases. The three amanitins were detected by negative electrospray ionization tandem mass spectrometry in the multiple reaction monitoring (MRM) mode and quantified by the solvent standard curve external standard method. Method validation was performed as recommended by the European Drug Administration (EMEA). Four levels of quality control (QC) samples were prepared, which covered the calibration curve range, viz., the limit of quantification (LOQ), within three times the LOQ (low QC), medium QC, and at 85% of the upper calibration curve range (high QC), and used to test the accuracy, precision, matrix effect, extraction recovery, and stability. The calibration curves for the three amanitins showed good linear relationships in the range of 0.1-200 ng/mL, and the correlation coefficients (r) were greater than 0.999. The matrix effects and extraction efficiencies of the three amanitins in urine and plasma were 92%-108% and 90%-103%, respectively, and the coefficients of variation were less than 13%. The accuracies of the three amanitins in urine were within -9.4%-8.0%. The repeatability and intermediate accuracies were 3.0%-14% and 3.5%-18%, respectively. When the sampling volume was 2.00 mL, the limits of detection of the three amanitins in urine were 0.002 ng/mL. The accuracies of the three amanitins in plasma were within -13%-8.0%. The repeatability and intermediate accuracies were 3.9%-9.7% and 5.5%-12%, respectively. When the sampling volume was 1.00 mL, the limits of detection of the three amanitins in plasma were 0.004 ng/mL. The developed method is simple, sensitive, and accurate. During toxic mushroom poisoning detection, 0.0067 ng/mL of α-amanitin and 0.0059 ng/mL of β-amanitin were detected in the urine of poisoned patients 138 h after ingesting poisonous mushrooms. This method has successfully solved the problem of detecting ultra-trace levels of amanitins in the urine and plasma of poisoned patients. It has important practical significance for the early diagnosis, early treatment, and mortality reduction of suspected poisoning patients. This method can also provide reliable technical support for future research on the toxicological effects and in vivo metabolism of these toxins.

Online Turbulent Flow Extraction and Column Switching for the Confirmatory Analysis of Stimulants in Urine by Liquid Chromatography-Mass Spectrometry

Stimulants are often used to treat attention deficit disorders and nasal congestion. As they can be misused and overdosed, the detection of stimulants is relevant in the toxicological field as well as in the doping control field. The effects of stimulants can indeed be beneficial for athletes. Therefore, their in-competition use is prohibited by the World Anti-Doping Agency (WADA). As stimulants represent one of the most detected categories of prohibited substances, automation of methods to detect and confirm their presence is desirable. Previous work has shown the advantages of using turbulent flow online solid-phase extraction liquid chromatography-tandem mass spectrometry (online SPE LC-MS-MS) for the detection and confirmation of diuretics and masking agents. Hence, a turbulent flow online SPE LC-MS-MS method, compliant with the WADA's identification criteria, was developed and validated for the detection and confirmation of 80 stimulants or metabolites with limits of identification varying between 10 (or possibly lower) and 100 ng/mL. As several metabolites are common metabolites for multiple administered stimulants, this means that with this method, misuse of well over 100 compounds can be detected. As the developed method uses the same columns and mobile phases as our turbulent flow online SPE LC-MS-MS method for the confirmation of diuretics and masking agents, there is no need to change the configuration of the instrument when switching between the diuretics method and the developed stimulants method.

MASS SPECTROMETRY ANALYSIS OF DRUGS OF ABUSE: CHALLENGES AND EMERGING STRATEGIES

Mass spectrometry has been the "gold standard" for drugs of abuse (DoA) analysis for many decades because of the selectivity and sensitivity it affords. Recent progress in all aspects of mass spectrometry has seen significant developments in the field of DoA analysis. Mass spectrometry is particularly well suited to address the rapidly proliferating number of very high potency, novel psychoactive substances that are causing an alarming number of fatalities worldwide. This review surveys advancements in the areas of sample preparation, gas and liquid chromatography-mass spectrometry, as well as the rapidly emerging field of ambient ionization mass spectrometry. We have predominantly targeted literature progress over the past ten years and present our outlook for the future. © 2020 Periodicals, Inc. Mass Spec Rev.

Fast Quantification Without Conventional Chromatography, The Growing Power of Mass Spectrometry

Mass spectrometry (MS) in hyphenated techniques is widely accepted as the gold standard quantitative tool in life sciences. However, MS possesses intrinsic analytical capabilities that allow it to be a stand-alone quantitative technique, particularly with current technological advancements. MS has a great potential for simplifying quantitative analysis without the need for tedious chromatographic separation. Its selectivity relies on multistage MS analysis (MSⁿ), including tandem mass spectrometry (MS/MS), as well as the ever-growing advancements of high-resolution MS instruments. This perspective describes various analytical platforms that utilize MS as a stand-alone quantitative technique, namely, flow injection analysis (FIA), matrix assisted laser desorption ionization (MALDI), including MALDI-MS imaging and ion mobility, particularly high-field asymmetric waveform ion mobility spectrometry (FAIMS). When MS alone is not capable of providing reliable quantitative data, instead of conventional liquid chromatography (LC)-MS, the use of a guard column (i.e., fast chromatography) may be sufficient for quantification. Although the omission of chromatographic separation simplifies the analytical process, extra procedures may be needed during sample preparation and clean-up to address the issue of matrix effects. The discussion of this manuscript focuses on key parameters underlying the uniqueness of each technique for its application in quantitative analysis without the need for a chromatographic separation. In addition, the potential for each analytical strategy and its challenges are discussed as well as improvements needed to render them as mainstream quantitative analytical tools. Overcoming the hurdles for fully validating a quantitative method will allow MS alone to eventually become an indispensable quantitative tool for clinical and toxicological studies.

Development of a high-throughput screening analysis for 288 drugs and poisons in human blood using Orbitrap technology with gas chromatography-high resolution accurate mass spectrometry

The screening analysis for drugs and poisons always symbolizes the capabilities of a forensic laboratory. Due to the rapid emergence of new compounds in clinical and forensic intoxication cases, sensitive and specific methods are necessary for the screening of wide range of target compounds. A novel high-throughput screening method has been developed for the toxicological analysis of 288 drugs and poisons in human blood using Orbitrap technology with gas chromatography-high resolution mass spectrometry (GC-HRMS). This method allows for the fast detection and identification of high-throughput forensically important drugs and poisons, e.g., drugs of abuse (cocaine, amphetamines, synthetic cannabinoids, opiates, hallucinogen), sedative-hypnotics, antidepressants, non-steroidal anti-inflammatory drugs, pesticides (acaricides, fungicides, insecticides, nematicides), and cardiovascular agents in one single GC-Q Exactive run. After a simple extraction with ethyl ether and buffer, following centrifugation, the supernatant was injected into the system. For detection, spiked blood samples were analyzed by Orbitrap-GC-HRMS using an electrospray ionization in full scan mode with a scan range from 40 to 650 (m/z). The identification of drugs and poisons in the samples was carried out by searching the accurate molecular mass of characteristic fragment ions, ion rations and retention time (RT) against the in-house library that we developed with 70 ev electron energy. The limit of detection (LOD) for most compounds (249 in a total of 288 compounds) was below 100 ng/mL. For selectivity, no substances have been identified in drug-free blood samples from six different sources, and the method was suitable for the recovery and the carryover. The coefficient of variation (CV) of the RTs was below 0.99% in all reproducibility experiments. Mass accuracy was always better than 3 ppm, corresponding to a maximum mass error of 1.04 millimass units (mmu). The developed method was applied to 136 real samples from forensic cases, demonstrating its suitability for the sensitive and fast screening of high-throughput drugs in human blood samples.

Critical assessment of different methods for quantitative measurement of metallodrug-protein associations

Quantitative screening for potential drug-protein binding is an essential step in developing novel metal-based anticancer drugs. ICP-MS approaches are at the core of this task; however, many applications lack in the capability of large-scale high-throughput screenings and proper validation. In this work, we critically discuss the analytical figures of merit and the potential method-based quantitative differences applying four different ICP-MS strategies to ex vivo drug-serum incubations. Two candidate drugs, more specifically, two Pt(IV) complexes with known differences of binding affinity towards serum proteins were selected. The study integrated centrifugal ultrafiltration followed by flow injection analysis, turbulent flow chromatography (TFC), and size exclusion chromatography (SEC), all combined with inductively coupled plasma-mass spectrometry (ICP-MS). As a novelty, for the first time, UHPLC SEC-ICP-MS was implemented to enable rapid protein separation to be performed within a few minutes at > 90% column recovery for protein adducts and small molecules. Graphical abstract Quantitative screening for potential drug-protein binding is an essential step in developingnovel metal-based anticancer drugs.

Identification and confirmation of diuretics and masking agents in urine by turbulent flow online solid-phase extraction coupled with liquid chromatography-triple quadrupole mass spectrometry for doping control

Diuretics can be misused to force diuresis to achieve weight loss or to mask the intake of a prohibited substance and are therefore prohibited by the World Anti-Doping Agency (WADA). For similar reasons other masking agents (vaptans, probenecid, etc.) are also prohibited by the WADA. The currently employed methods to detect diuretics in urine use extraction or dilute-and-shoot, combined with 1D- liquid chromatography (LC) high resolution mass spectrometry (MS) or LC-triple quadrupole MS. Dilute-and-shoot methods save time and work, but these methods encounter some problems (e.g., peak drift and matrix effect). Therefore, a 2D-LC-MS/MS application was developed, validated and evaluated as an alternative. The effect of a turbulent flow rate was studied by loading samples under different conditions and the turbulent flow rate was found to be more effective in removing matrix interferences. A correlation with the specific gravity was observed. A turbulent flow online solid phase extraction (SPE) method combined with LC-MS/MS for the detection of 50 diuretics and masking agents was developed and validated for identification purposes. This method combines the advantages of dilute-and-shoot while solving the issues of matrix effect and retention time shift. Furthermore, the presented method is compliant with WADA's identification criteria and can hence be used for screening and/or confirmation.

Blood plasma level determination using an automated LC-MSn screening system and electronically stored calibrations exemplified for 22 drugs and two active metabolites often requested in emergency toxicology

Fast and comprehensive qualitative and quantitative methods preferably by gas chromatography-mass spectrometry (GC-MS) and/or liquid chromatography-mass spectrometry (LC-MS) are needed to support the (differential) diagnosis of acute poisonings in emergency toxicology. One option is a commercially available qualitative screening solution based on LC-MSⁿ (Bruker Daltonik Toxtyper™, TT). Identified and toxicologically relevant compounds should be quantified to assess severity of poisonings. The aim of the present study was to test the TT system for quantification simultaneous with the screening process in blood plasma exemplified for 22 relevant drugs and two active metabolites. A standard liquid-liquid extraction was used for sample work-up followed by 1:5 dilution of the final extracts. They were analyzed using the TT system consisting of a Bruker amaZon speed ion trap and a Thermo Fisher Dionex Ultimate 3000 LC system. Plasma levels were assessed using full-scan data and an electronically stored five-point calibration. The calibration model was linear for the studied ranges and could be used for at least two months. The method was validated according to international guidelines. The acceptance criteria recommended for emergency toxicology for accuracy and precision were fulfilled for all tested compounds, but bromazepam, lorazepam, oxycodone, and prothipendyl could reliably be determined only above the therapeutic range. In conclusion, the presented procedure allowed the combination of a comprehensive LC-MSⁿ screening with fast automated assessment of plasma levels for emergency toxicology of tested compounds.

LC-HR-MS/MS standard urine screening approach: Pros and cons of automated on-line extraction by turbulent flow chromatography versus dilute-and-shoot and comparison with established urine precipitation

Comprehensive urine screening for drugs and metabolites by LC-HR-MS/MS using Orbitrap technology has been described with precipitation as simple workup. In order to fasten, automate, and/or simplify the workup, on-line extraction by turbulent flow chromatography and a dilute-and-shoot approach were developed and compared. After chromatographic separation within 10min, the Q-Exactive mass spectrometer was run in full scan mode with positive/negative switching and subsequent data dependent acquisition mode. The workup approaches were validated concerning selectivity, recovery, matrix effects, process efficiency, and limits of identification and detection for typical drug representatives and metabolites. The total workup time for on-line extraction was 6min, for the dilution approach 3min. For comparison, the established urine precipitation and evaporation lasted 10min. The validation results were acceptable. The limits for on-line extraction were comparable with those described for precipitation, but lower than for dilution. Thanks to the high sensitivity of the LC-HR-MS/MS system, all three workup approaches were sufficient for comprehensive urine screening and allowed fast, reliable, and reproducible detection of cardiovascular drugs, drugs of abuse, and other CNS acting drugs after common doses.

Acute Toxicity Associated With the Recreational Use of the Novel Psychoactive Benzofuran N-methyl-5-(2 aminopropyl)benzofuran

N-methyl-5-(2 aminopropyl)benzofuran (5-MAPB) is a novel psychoactive benzofuran, created by N-methylation of 5-(2-aminopropyl)benzofuran (5-APB), which shares structural features with methylenedioxymethamphetamine (MDMA). To our knowledge, no case of 5-MAPB-related toxicity has been published in the scientific literature. We report a case of oral 5-MAPB exposure confirmed by liquid chromatography-tandem mass spectrometry in a 24-year-old previously healthy white man. Observed symptoms and signs such as paleness, cold and clammy skin, hypertension, elevated high-sensitive troponin T level, tachycardia, ECG change, diaphoresis, mild hyperthermia, mydriasis, tremor, hyperreflexia, clonus, agitation, disorientation, hallucinations, convulsions, reduced level of consciousness, and creatine kinase level elevation (305 IU/L) were compatible with undesired effects related to 5-APB or MDMA exposure. Signs and symptoms resolved substantially within 14 hours with aggressive symptomatic treatment, including sedation with benzodiazepines, external cooling, analgesia and sedation with fentanyl-propofol, and treatment with urapidil, an α-receptor-blocking agent. 5-MAPB showed first-order elimination kinetics with a half-life of 6.5 hours, comparable to the half-life of MDMA. According to the chemical structure, this case report, and users' Web reports, 5-MAPB appears to have an acute toxicity profile similar to that of 5-APB and MDMA, with marked vasoconstrictor effect.

Validated multi-drug determination using liquid chromatography with tandem mass spectrometry for the evaluation of a commercial drug disposal product

Currently, there are limited effective means of drug disposal for consumers, and this creates a gateway to illicit use and environmental contamination. Here, we evaluated the efficacy of a new drug disposal product, composed from a slurry of activated carbon, which claims to sequester up to 100% of a drug's active ingredient when the loading capacity is not exceeded, making it safe to dispose in landfill. High-performance liquid chromatography with tandem mass spectrometry was applied to quantify as many as 24 drugs (opiates, barbiturates, statins, amphetamine, and benzodiazepine drugs) in the residual solvent solution from the product. Calibration curves were established in the concentration ranges of 0.25-7.0 μg/mL and showed good linearity. The limits of detection varied from 0.001 to 0.02 μg/mL, depending on the drug. Accuracy ranged from 80 to 111% for quality control samples, with a few minor exceptions. Precision overall varied between 0.2 to 12.7%. In sample bottles tested, where active ingredient of the loaded drug was below the maximum sorption capacity stated on the label, 98 to >99.9% of the active ingredient was sequestered. Percent active ingredient adsorbed was slightly lower in bottles loaded in excess of label specifications.

Multiple stage MS in analysis of plasma, serum, urine and in vitro samples relevant to clinical and forensic toxicology

This paper reviews MS approaches applied to metabolism studies, structure elucidation and qualitative or quantitative screening of drugs (of abuse) and/or their metabolites. Applications in clinical and forensic toxicology were included using blood plasma or serum, urine, in vitro samples, liquids, solids or plant material. Techniques covered are liquid chromatography coupled to low-resolution and high-resolution multiple stage mass analyzers. Only PubMed listed studies published in English between January 2008 and January 2015 were considered. Approaches are discussed focusing on sample preparation and mass spectral settings. Comments on advantages and limitations of these techniques complete the review.

Topical Timolol for Infantile Hemangiomas: Evidence for Efficacy and Degree of Systemic Absorption

BACKGROUND

Topical use of timolol for infantile hemangiomas has recently emerged with promising results. It is unknown whether topical β-blockers act locally or if their effect is partly due to systemic absorption. This study investigates whether topically applied timolol is absorbed and reports on the efficacy of this treatment.

METHODS

We treated 40 infants with small proliferating hemangiomas with topical timolol gel 0.5% twice daily and assessed urinary excretion and serum levels in a proportion of patients. Clinical response was evaluated on a visual analog scale of standardized photographs after 1, 2, 3, and 5 months.

RESULTS

Forty infants with a median age of 18 weeks (range 2-35 wks) were included; 23 (58%) had superficial and 17 (42%) mixed-type hemangiomas. The median size was 3 cm(2) (range 0.1-15 cm(2) ) and nine hemangiomas were ulcerated. The hemangiomas improved significantly during treatment, with a median increase in visual analog scale of 7 points after 5 months (p < 0.001). Urinalysis for timolol was performed in 24 patients and was positive in 20 patients (83%). In three infants, serum levels of timolol were also measured and were all positive (median 0.16 ng/mL [range 0.1-0.18 ng/mL]). No significant side effects were recorded.

CONCLUSION

Topical therapy with timolol is effective for infantile hemangiomas, but systemic absorption occurs. Serum levels in our patients were low, suggesting that using timolol for small hemangiomas is safe, but caution is advised when treating ulcerated or large hemangiomas, very young infants, or concomitantly using systemic propranolol.

Recent approaches for on-line analysis of residues and contaminants in food matrices: A review

This review highlights recent developments for on-line determination of residues and contaminants in complex matrices such as food samples. This involves the on-line coupling of a sample preparation technique (as the first "dimension") with a chromatographic system (second "dimension"), usually followed by mass spectrometry. Although frequently treated as quite distinct techniques, the role of all devices utilized as the first dimension in this approach aims to decrease the sample complexity while eliminating as much as possible the matrix contaminants to facilitate the qualitative and quantitative determination of the compounds of interest. This review will focus on the following techniques as the first dimension: (i) on-line solid-phase extraction; (ii) in-tube solid-phase microextraction; (iii) matrix solid-phase dispersion; and (iv) turbulent flow chromatography. The second dimension is usually performed using a chromatographic column to isolate the analyte(s) of interest for further mass spectrometry determination. A description of the basis of this on-line approach and its distinct set up possibilities is presented, which is followed by a critical review of the literature covering this subject in the last ten years (focusing on the last five years) with emphasis on the analysis of residue and contaminants in food samples.

Fully automated semi-quantitative toxicological screening in three biological matrices using turbulent flow chromatography/high resolution mass spectrometry

BACKGROUND

In clinical and forensic toxicology, fast and specific methods are needed for the screening of different classes of drugs. A complete general unknown screening procedure was developed using turbulent flow chromatography with electrospray ionization and Orbitrap mass spectrometry.

METHODS

After protein precipitation, samples were injected directly into the turbulent flow chromatographic system and analyzed with an Orbitrap mass spectrometer. The Exactive® operated in positive and negative modes with alternated high collision dissociation in order to obtain characteristic fragments. We built a library containing 616 compounds by analyzing a reference standard for all the molecules.

RESULTS

Identification was based on retention time, accurate measured mass, isotopic pattern and presence of specific fragments. For each substance, we set a calibration range encompassing infra-therapeutic, therapeutic, supra-therapeutic and toxic concentrations in order to generate semi-quantitative result. For 65% of the components, the limit of detection was below 5 ng/mL. The validation process showed the approach to be selective, sensitive, accurate and precise.

CONCLUSION

The method has been accredited by COFRAC (French Accreditation Committee) according to the ISO 15189 standard. Applicability was successfully tested by analyzing authentic serum, urine and whole blood samples.

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

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

Cardiovascular drug determination in bioanalysis: an update

The great impact of cardiovascular diseases in human health has led to the development of a huge number of drugs and therapies to improve the treatment of these diseases. Cardiovascular drug analysis in biological fluids constitutes an important challenge for analytical scientists. There is a clear need for reliable methods to carry out both qualitative and quantitative analysis in a short time of analysis. Different problems such as drug monitoring, analysis of metabolites, study of drugs interactions, drugs residues or degradation products, chiral separation, and screening and confirmation of drugs of abuse in doping control must be solved. New trends in sample preparation, instrumental and column technology advances in LC and innovations in MS are described in this work.

Development and validation of a rapid turboflow LC-MS/MS method for the quantification of LSD and 2-oxo-3-hydroxy LSD in serum and urine samples of emergency toxicological cases

Lysergic acid diethylamide (LSD) is a widely used recreational drug. The aim of the present study is to develop a quantitative turboflow LC-MS/MS method that can be used for rapid quantification of LSD and its main metabolite 2-oxo-3-hydroxy LSD (O-H-LSD) in serum and urine in emergency toxicological cases without time-consuming extraction steps. The method was developed on an ion-trap LC-MS/MS instrument coupled to a turbulent-flow extraction system. The validation data showed no significant matrix effects and no ion suppression has been observed in serum and urine. Mean intraday accuracy and precision for LSD were 101 and 6.84%, in urine samples and 97.40 and 5.89% in serum, respectively. For O-H-LSD, the respective values were 97.50 and 4.99% in urine and 107 and 4.70% in serum. Mean interday accuracy and precision for LSD were 100 and 8.26% in urine and 101 and 6.56% in serum, respectively. For O-H-LSD, the respective values were 101 and 8.11% in urine and 99.8 and 8.35% in serum, respectively. The lower limit of quantification for LSD was determined to be 0.1 ng/ml. LSD concentrations in serum were expected to be up to 8 ng/ml. 2-Oxo-3-hydroxy LSD concentrations in urine up to 250 ng/ml. The new method was accurate and precise in the range of expected serum and urine concentrations in patients with a suspected LSD intoxication. Until now, the method has been applied in five cases with suspected LSD intoxication where the intake of the drug has been verified four times with LSD concentrations in serum in the range of 1.80-14.70 ng/ml and once with a LSD concentration of 1.25 ng/ml in urine. In serum of two patients, the O-H-LSD concentration was determined to be 0.99 and 0.45 ng/ml. In the urine of a third patient, the O-H-LSD concentration was 9.70 ng/ml.

Acute toxicity associated with the recreational use of the novel dissociative psychoactive substance methoxphenidine

INTRODUCTION

Methoxphenidine is a novel dissociative designer drug of the diarylethylamine class which shares structural features with phencyclidine (PCP), and is not at present subject to restrictive regulations. There is very limited information about the acute toxicity profile of methoxphenidine and the only sources are anonymous internet sites and a 1989 patent of the Searle Company. We report a case of analytically confirmed oral methoxphenidine toxicity.

CASE DETAILS

A 53-year-old man was found on the street in a somnolent and confusional state. Observed signs and symptoms such as tachycardia (112 bpm), hypertension (220/125 mmHg), echolalia, confusion, agitation, opisthotonus, nystagmus and amnesia were consistent with phencyclidine-induced adverse effects. Temperature (99.1°F (37.3°C)) and peripheral oxygen saturation while breathing room air (99%) were normal. Laboratory analysis revealed an increase of creatine kinase (max 865 U/L), alanine aminotransferase (72 U/L) and gamma-glutamyl transpeptidase (123 U/L). Methoxphenidine was identified by a liquid chromatography tandem mass spectrometry toxicological screening method using turbulent flow online extraction in plasma and urine samples collected on admission. The clinical course was favourable and signs and symptoms resolved with symptomatic treatment.

CONCLUSION

Based on this case report and users' web reports, and compatible with the chemical structure, methoxphenidine produces effects similar to those of the arylcyclohexylamines, as PCP.

The current role of on-line extraction approaches in clinical and forensic toxicology

In today's clinical and forensic toxicological laboratories, automation is of interest because of its ability to optimize processes, to reduce manual workload and handling errors and to minimize exposition to potentially infectious samples. Extraction is usually the most time-consuming step; therefore, automation of this step is reasonable. Currently, from the field of clinical and forensic toxicology, methods using the following on-line extraction techniques have been published: on-line solid-phase extraction, turbulent flow chromatography, solid-phase microextraction, microextraction by packed sorbent, single-drop microextraction and on-line desorption of dried blood spots. Most of these published methods are either single-analyte or multicomponent procedures; methods intended for systematic toxicological analysis are relatively scarce. However, the use of on-line extraction will certainly increase in the near future.

Detection and identification of drugs and toxicants in human body fluids by liquid chromatography-tandem mass spectrometry under data-dependent acquisition control and automated database search

Systematic toxicological analysis (STA) is aimed at detecting and identifying all substances of toxicological relevance (i.e. drugs, drugs of abuse, poisons and/or their metabolites) in biological material. Particularly, gas chromatography-mass spectrometry (GC/MS) represents a competent and commonly applied screening and confirmation tool. Herein, we present an untargeted liquid chromatography-tandem mass spectrometry (LC/MS/MS) assay aimed to complement existing GC/MS screening for the detection and identification of drugs in blood, plasma and urine samples. Solid-phase extraction was accomplished on mixed-mode cartridges. LC was based on gradient elution in a miniaturized C18 column. High resolution electrospray ionization-MS/MS in positive ion mode with data-dependent acquisition control was used to generate tandem mass spectral information that enabled compound identification via automated library search in the "Wiley Registry of Tandem Mass Spectral Data, MSforID". Fitness of the developed LC/MS/MS method for application in STA in terms of selectivity, detection capability and reliability of identification (sensitivity/specificity) was demonstrated with blank samples, certified reference materials, proficiency test samples, and authentic casework samples.

Clinical applications of fast liquid chromatography: a review on the analysis of cardiovascular drugs and their metabolites

One of the major challenges facing the medicine today is developing new therapies that enhance human health. To help address these challenges the utilization of analytical technologies and high-throughput automated platforms has been employed; in order to perform more experiments in a shorter time frame with increased data quality. In the last decade various analytical strategies have been established to enhance separation speed and efficiency in liquid chromatography applications. Liquid chromatography is an increasingly important tool for monitoring drugs and their metabolites. Furthermore, liquid chromatography has played an important role in pharmacokinetics and metabolism studies at these drug development stages since its introduction. This paper provides an overview of current trends in fast chromatography for the analysis of cardiovascular drugs and their metabolites in clinical applications. Current trends in fast liquid chromatographic separations involve monolith technologies, fused-core columns, high-temperature liquid chromatography (HTLC) and ultra-high performance liquid chromatography (UHPLC). The high specificity in combination with high sensitivity makes it an attractive complementary method to traditional methodology used for routine applications. The practical aspects of, recent developments in and the present status of fast chromatography for the analysis of biological fluids for therapeutic drug and metabolite monitoring, pharmacokinetic studies and bioequivalence studies are presented.

Rapid and semiautomated method for the analysis of veterinary drug residues in honey based on turbulent-flow liquid chromatography coupled to ultrahigh-performance liquid chromatography-Orbitrap mass spectrometry (TFC-UHPLC-Orbitrap-MS)

A simple and rapid method is described for the determination of veterinary drug (VD) residues in honey samples using turbulent flow chromatography coupled to ultrahigh-performance liquid chromatography-Orbitrap mass spectrometry (TFC-UHPLC-Orbitrap-MS). Honey samples were diluted with an aqueous solution of Na(2)EDTA (0.1 M). Then, they were injected into the chromatographic system including a TFC column. Afterward, the analytes were transferred to an UHPLC analytical column, where they were determined by UHPLC-Orbitrap-MS. Mean recoveries were obtained at three concentration levels (5, 10, and 50 μg/kg), ranging from 68 to 121% for most compounds. Repeatability (intraday precision) and interday precision (expressed as relative standard deviation, RSD) were <25% for most compounds. Limits of quantification (LOQs) ranged from 5 to 50 μg/kg and limits of identification (LOIs) from 0.1 to 50 μg/kg. The developed method was applied in honey samples, and it was fast and nonlaborious.

Acute neurotoxicity associated with recreational use of methylmethaqualone confirmed by liquid chromatography tandem mass spectrometry

Methylmethaqualone is a sedative designer drug created by adding a methyl group to the 3-phenyl ring of methaqualone, and is at present not subject to restrictive regulation in many countries. To our knowledge, no case of methylmethaqualone abuse has been published to date in the scientific literature, and the only sources of information are users' reports on Web discussion forums and data from preclinical animal studies. We report a case of oral methylmethaqualone abuse confirmed by liquid chromatography tandem mass spectrometry in a 24-year-old previously healthy Caucasian male. Observed symptoms and signs such as central nervous system depression alternating with excitation, psychomotor agitation, muscle hyperactivity, and tachycardia were compatible with methaqualone-induced adverse effects. Except for the mild tachycardia (115 beats/min), other vital signs were normal: blood pressure 134/89 mmHg, body temperature 36.2°C (97.16°F), and peripheral oxygen saturation 99% while breathing room air. The ECG showed no prolongation of the QT interval and the QRS duration was normal. Laboratory analysis revealed a slight increase in creatine kinase (368 U/L) and alanine aminotransferase (90 U/L) serum concentrations. Blood alcohol concentration was 0.32 g/L. Methylmethaqualone was identified in a serum sample collected on admission which was analyzed by a liquid chromatography tandem mass spectrometry toxicological screening method using turbulent flow online extraction. After a few days the patient ingested the same amount of substance with identical symptoms. Based on the chemical structure and animal data, and according to this case report and users' Web reports, methylmethaqualone appears to have a similar acute toxicity profile to methaqualone, with marked psychomotor stimulation. Symptoms of acute toxicity can be expected to resolve with supportive care.

Online microchannel preconcentrator for carbofuran detection

A simple and rapid online microchannel preconcentrator coupled with an amperometric detection for the analysis of carbofuran using polyethylene glycol coated onto magnetic particle (PEG-magnetic particles) sorbents was developed. This simple-to-prepare microchannel preconcentrator used an external magnet to retain the PEG-magnetic particle sorbents inside the microchannel. Under optimum conditions, the system provided two linear ranges, from 0.01 to 10.0 mg L(-1) and from 10.0 to 130.0 mg L(-1) with a limit of detection of 8.7 ± 0.1 μg L(-1). The microchannel preconcentrator provided very good stability; it can be used for up to 326 consecutive injections of 5.0 mg L(-1) carbofuran with a relative standard deviation of less than 3%. The developed system provided a good microchannel-to-microchannel and a good electrode-to-electrode reproducibility (n = 6, %RSD < 1). It also provided an excellent selectivity when it was tested with two other carbamate pesticides, carbaryl and methomyl, with a 43 and 256 times higher detection sensitivity for carbofuran, respectively. The developed system was successfully applied to detect carbofuran in surface water samples obtained near vegetable plantation areas. The concentrations of carbofuran in these samples were found to be in the range of non-detectable to 0.047 ± 0.001 mg L(-1). The developed system is easy to operate and easy to couple with other analytical instruments and it could be easily adapted for the analysis of other polar organic contaminants.

Direct bioanalytical sample injection with 2D LC–MS

New analytical platforms have been developed in response to the need for attaining increased peak capacity for multicomponent complex analysis with higher sensitivity and characterization of the analytes, and high-throughput capabilities. This review outlines the fundamental principles of target and comprehensive 2D LC method development and encompasses applications of LC–LC and LC × LC coupled to MS in bioanalysis using a variety of online analytical procedures. It also provides a rationale for the usage of the most employed mass analyzers and ionization sources on these platforms.

How can analytical diagnostics in clinical toxicology be successfully performed today?

This article discusses current strategies for efficient analytical diagnostics in clinical toxicology. The tasks for such diagnostics, different analytical strategies and various methods were reviewed. They cover mainly gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry procedures for target or comprehensive screening for drugs (of abuse) and poisons, and for quantification in blood. Quality control aspects and strategies for competent interpretation of the analytical result in correlation with the clinical signs presented by the patient are discussed.