Direct drug analysis from oral fluid using medical swab touch spray mass spectrometry

Influence of Solvent Relative Permittivity in Swab Spray Mass Spectrometry

The influence of solvent properties on ion generation by swab spray ionization was investigated. The ability of a variety of solvents of different relative permittivity, surface tension, and viscosity to form a stable and reproducible electrospray was examined. It is demonstrated that in swab spray ionization, a crucial balance between solvent composition, applied potential, and the solvent flow fed to the swab head must be maintained. The solvent composition was found to significantly affect the shape of the Taylor cone and the emerging cone jet, which eventually have an impact on the resulting ion yield. The results indicate that the relative permittivity of solvents measured under standard conditions is the main factor governing jet shaping, and consequently, the ionization efficacy. Short jets, which are required for maximum ion yield, were observed for solvents with relative permittivity εr higher than 25. Solvents exhibiting lower relative permittivity required the addition of 20% to 60% methanol to limit the jet length and to avoid the ineffective dripping pulsation. The observed effects were compared to conventional electrospray ionization and paper spray ionization.

Swab-in-Capillary Electrospray Ionization and a Miniature Mass Spectrometer for In Situ Drug Analysis

In situ analysis of drugs has been in increasing demand in many fields. As an updated version of capillary-in-capillary electrospray ionization (CC-ESI) developed previously, a disposable swab-in-capillary electrospray ionization (SC-ESI) source was designed in this study. With a micro medical swab for sampling and an integrated filter membrane for online filtration, SC-ESI was able to directly sample and MS analyze complex samples without the need for pretreatment. Coupled with a miniature mass spectrometer, SC-ESI was applied for direct analysis of effective ingredients in therapeutic drugs (in tablet, capsule, and liquid droplet) and drugs in saliva and quantitation of therapeutic drugs in blood. The limits of detection in absolute amounts were obtained as 1 ng for fentanyl and 0.5 ng for cocaine in saliva. Combining with an internal standard method, SC-ESI acquired linear quantitation ranges of 100-5000 ng/mL for imatinib in whole blood and 100-2000 ng/mL for clozapine in serum with high accuracies and precisions. The entire analysis process, from sampling to data acquisition, can be completed in less than 2 min. As demonstrated as a cheap, portable, and sampling-effective ionization source, SC-ESI has shown great potential for in situ drug analysis, especially in border drug screening and clinical therapeutic drug monitoring.

Analysis of Pesticide Residues on Fruit Using Swab Spray Ionization Mass Spectrometry

The vast quantity and high variety of pesticides globally used in agriculture entails considerable risks for the environment and requires ensuring the safety of food products. Therefore, powerful analytical tools are needed to acquire qualitative and quantitative data for monitoring pesticide residues. The development of ambient ionization mass spectrometry methods in the past two decades has demonstrated numerous ways to generate ions under atmospheric conditions and simultaneously to reduce the need for extended sample preparation and circumvent chromatographic separation prior to mass analysis. Swab spray ionization enables the generation of ions directly from swabs via the application of high voltage and solvent flow. In this study, swab sampling of fruit surfaces and subsequent ionization directly from the swab in a modified electrospray ion source was employed for the screening and quantitation of pesticide residues. Aspects regarding sample collection, sampling efficacy on different surfaces, and swab background are discussed. The effect of solvent composition on pesticide-sodium adduct formation and the suppression of ionization by the background matrix have been investigated. Furthermore, a novel approach for the quantitation of pesticide residues based on depletion curve areas is presented. It is demonstrated that swab spray ionization is an effective and quick method for spectral library-based identification and the quantitative analysis of polar contact pesticide residues on food.

From the laboratory to the field: Chemical analysis of colored smoke pyrotechnic formulations via mass spectrometry techniques

Smoke dyes are complex molecular systems that have the potential to form many molecular derivatives and fragments when deployed. The chemical analysis of smoke samples is challenging due to the adiabatic temperature of the pyrotechnic combustion and the molecular complexity of the physically dispersed reaction products. Presented here is the characterization of the reaction byproducts of a simulant Mk124 smoke signal on a multigram scale, which contain the dye disperse red 9 (1-(methylamino)anthraquinone), by ambient ionization mass spectrometry. Our previous work has examined the thermal decomposition of a simplified smoke system consisting of disperse red 9, potassium chlorate, and sucrose by anaerobic pyrolysis gas chromatography mass spectrometry performed at the laboratory milligram scale. The results from the lab scale test were compared with a fully functioned Mk124 in the field. To achieve this, Mk124 smokes were functioned in the presence of sampling swabs that collected byproduct residues from the smoke plume in the ambient environment. These swabs were then analyzed using ambient ionization mass spectrometry to identify the expended pyrotechnic residues, with particular interest in halogenated species. Previous work determined the toxicity of unforeseen byproducts identified on the laboratory scale, which were also detected in the field demonstrating the correlation of the laboratory testing to the fielded systems. By understanding the chemical composition of smokes and their reaction products, potential toxicity effects can be easily assessed, leading to safer formulations with improved performance. These results can help assess how smoke byproducts may impact Warfighter performance, personnel health, and the environment.

Rapid quality evaluation of Chinese herbal medicines using a miniature mass spectrometer: Lygodium japonicum (Thunb.) Sw. as an example

The quality of Chinese herbal medicine (CHM) raw materials is essential, and mass spectrometry (MS)-based technologies have been playing key roles in the quality control of CHMs. However, the use of miniature mass spectrometry (mini-MS) for quality control of CHMs has rarely been reported. In this work, we developed a rapid analytical method for the quality evaluation of CHMs based on paper spray ionization (PSI)-mini-MS/MS. The quality evaluation of Lygodium japonicum (Thunb.) Sw. was used as an example. Following a "multi-component" quality evaluation strategy, nine active constituents of L. japonicum were selected to be used as analytes for quality control. We confirmed that the precursor-product ion information in the MS/MS spectra of each analyte in the herbal extracts was consistent with the standards. Also, we developed a mini-MS-based quantitative method for each analyte using its quantification ion. The quantitative methodology was rigorously validated using quality control samples. Finally, the quality evaluation of L. japonicum was carried out using the established MS/MS method combined with statistical analysis. A wide range of common quality issues with L. japonicum can be effectively determined, including whether it is adulterated with sand and distinguishing among different parts and species. This study demonstrates that mini-MS for quality evaluation of CHMs is feasible. Mini-MS for quality evaluation of herbal medicines will potentially have a good prospect due to its many advantages such as low cost, low power consumption, and portability in the future.

Direct adsorption sampling and ambient mass spectrometry analysis of tobacco smoke with porous paper strips

Chemical analysis of atmospheric aerosols by conventional analytical methods is usually required to perform complicated and time-consuming sample preparation processes. In recent decades, ambient ionization mass spectrometry (AI-MS) methods have been proven to be simple, rapid, and effective analytical tools for direct analysis of various complex samples. In this work, we applied porous paper filters for direct adsorptive sampling of tobacco smoke, and then the sampled paper filters were performed the emitters of the paper spray ionization (PSI) device. An auto-sampling device was made to control the generation and collection of tobacco smoke. Nicotine, the typical compound of tobacco smoke, was used to optimize the key conditions of auto-sampling. Moreover, different types of tobacco smoke were also compared with multivariate variable analysis, and the makers of tobacco smoke from different sources of tobacco smoke were investigated. By using this method, direct sampling and analysis of a single tobacco sample can be completed within minutes. Overall, our results show that PSI-MS is a powerful tool that integrates collection, extraction, ionization, and identification analytes in smoke.

Electrospray ionization mass spectrometry with wooden tips: A review

Electrospray ionization (ESI) is a powerful ionization technique in mass spectrometry (MS). There has been an increasing interest for the new development of ESI technique to extend its applications. ESI-MS with wooden tips (wooden-tip ESI-MS), an ESI technique invented in 2011, enabled not only new applications but also new insights into the ESI mechanism. In this review, the technical aspects of wooden-tip ESI-MS are described, the new features of wooden-tip ESI-MS for sampling and ionization of analytes are highlighted, and the important applications of wooden-tip ESI-MS in various fields in the past 10 years, including food safety, forensic investigation, environmental analysis, biomedical analysis and protein study, are summarized. The perspectives on the further development and applications of wooden-tip ESI-MS are also discussed.

Online SPE UPLC-MS/MS method for the simultaneous determination of 33 psychoactive drugs from swab-collected human oral fluid samples

Oral fluid is easy and safe to collect and allows the detection of drugs of abuse after local exposure by oral, smoked, and/or inhaled intake, or systemic exposure. A routine online solid-phase extraction UPLC-MS/MS method was developed for the simultaneous determination of 33 psychoactive drugs in oral fluid. The selected drugs were fourteen fentanyl analogs and nineteen other abused psychoactive compounds, including classical narcotics, which were analyzed in a run of 10 min. Limits of detection and of quantification ranged from 0.02 to 1 ng/mL and from 0.02 to 5 ng/mL depending on the analyte, respectively. Matrix effect was in the range - 17 to + 15.7% for all analytes having a deuterated analog. Accuracy ranged from 82.7 to 113.4% and precision CV was at worst of 18.6%. Carryover was below 0.8% for all analytes. Recovery from FLOQSwabs™ showed high variability between analytes with THC, D2FF, 4-ANPP, ocfentanil, and valerylfentanyl being recovered below 40%. A stability study performed over 2 weeks on collecting devices loaded with artificial oral fluid showed huge variation between analytes with morphine, BZE, and norfentanyl being the more stable. Storage at 4 °C allowed drug detection for 1 week except for THC and remifentanil. The method was successfully applied to the detection of abused psychoactive compounds in oral fluid samples from 6 patients admitted to an addiction department.

Spherical Sampler Probes Enhance the Robustness of Ambient Ionization Mass Spectrometry for Rapid Drugs Screening

Ambient ionization mass spectrometry has become one of the most promising approaches for rapid and high-throughput screening of small molecules in complex biological matrices for emergency medicine, forensics, and food and agriculture applications. The simple procedures for sample collection and ionization without additional pretreatment are vital in these fields. Many efforts have been devoted to modifying various ambient ionization techniques to simplify the procedures and improve the robustness and sensitivity of the methods. Here, we demonstrate the implementation of rigid spherical sampler probes to improve the robustness of touch spray ionization mass spectrometry. The sphericity of the probes increases the stability of the cone-jet mode of electrospray, reduces the requirements for fine positioning of a sampler in the ion source, and decreases the possibility of corona discharge occurrence. The utilization of spherical sampler probes allows fast, non-invasive sampling, followed by rapid analysis for various drugs of different chemical classes in complex biological matrices, such as the whole blood or sebum collected from the skin surface. The linearity of the analytical signal response from drug concentration confirms the possibility of creating a simple semiquantitative method for small molecules monitoring using spherical sampler probes.

Direct analysis of naphthenic acids in produced water and crude oil by NH2-surface-modified wooden-tip electrospray ionization mass spectrometry

This work describes the surface coating of wooden toothpicks with amino groups (NH₂) for electrospray ionization mass spectrometry (MS) analysis of naphthenic acids (NAs) in produced water samples and crude oil fractions. NH₂ was introduced into the cellulosic material through a silanization reaction using aminopropyltriethoxysilane. An NH₂-modified toothpick was inserted into the analyte extraction sample and was subsequently used as an electrospray emitter for MS analysis. The extraction conditions were optimized by analyzing NAs (benzoic acid, 1-naphthoic acid, decanoic acid, 3,5-dimethyladamantane-1-carboxylic acid, and 3,5-dimethyladamantane-1-acetic acid) in pure water, and the best condition was using 5 min of extraction time with the samples under agitation. Modified and unmodified wooden toothpicks were compared, and the intensities of all NAs were higher when using the modified substrates than when using the unmodified ones. Limit of detection (LOD), limit of quantification (LOQ), linearity, precision, and recovery were determined by analyzing decanoic acid in seawater samples. The LOD and LOQ were 2 and 5 μg mL^-1, respectively, and a linear correlation (R² = 0.9927) was obtained with concentrations ranging from 5 to 250 μg mL^-1. Precision values ranged from 6 to 13% and recoveries from 89 to 106%. The technique was also employed to analyze three produced water samples, in which decanoic acid was semi-quantified, and the concentrations ranged from 10 to 13 μg mL^-1. High abundances of acidic compounds of class O2 with DBEs (double bond equivalents) ranging from 1 to 3 and carbon numbers going from 8 to 12 were detected in the produced water samples. The results suggest that the modification of wooden toothpicks with NH₂ might offer a significant advancement in the knowledge of cheap substrates that can improve the sensitivity of analysis of NAs in water samples.

FIELDABLE MASS SPECTROMETRY FOR FORENSIC SCIENCE, HOMELAND SECURITY, AND DEFENSE APPLICATIONS

Mass spectrometry is commonly used in forensic chemistry laboratories for sensitive, definitive analysis. There have been significant efforts to bring mass spectrometry analysis on-site through the development of ruggedized, fieldable instruments. Testing samples in the field is of particular interest in forensic science, homeland security, and defense applications. In forensic chemistry, testing seized drugs in the field can significantly improve efficiencies in processing of related criminal cases. The screening of passengers and luggage at transportation hubs is a critical need for homeland security for which mass spectrometry is well suited to provide definitive answers with low false positive rates. Mass spectrometry can yield reliable data for military personnel testing sites for potential chemical weapons release. To meet the needs of the forensic and security communities fieldable mass spectrometers based on membrane inlet systems and hybrid gas chromatography systems have been developed and commercialized. More recently developed ambient ionization mass spectrometry methods can eliminate the time, equipment, and expertise associated with sample preparation, and so are especially appealing for on-site analysis. We describe the development of fieldable mass spectrometry systems, with emphasis on commercially available systems that have been deployed for on-site analysis of seized drugs, chemical warfare agents, explosives, and other analytes of interest to the forensic and security communities. © 2020 John Wiley & Sons Ltd. Mass Spec Rev.

The key role of mass spectrometry in comprehensive research on new psychoactive substances

New psychoactive substances (NPS) are a wide group of compounds that try to mimic the effects produced by the 'classical' illicit drugs, including cannabis (synthetic cannabinoids), cocaine and amphetamines (synthetic cathinones) or heroin (synthetic opioids), and which health effects are still unknown for most of them. Nowadays, more than 700 compounds are being monitored by official organisms, some of which have been recently identified in seizures and/or intoxication cases. Toxicological analysis plays a pivotal role in NPS research. A comprehensive investigation on NPS, from the first identification of a novel substance until its detection in drug users to help in diagnostics and medical treatment, requires the use of a wide variety of instruments and analytical strategies. This paper illustrates the key role of mass spectrometry (MS) along a comprehensive investigation on NPS. The synthetic cannabinoid XLR-11 and the synthetic cathinone 5-PPDi have been chosen as representative substances of the most consumed NPS families. Moreover, both compounds have been investigated at our laboratory in different stages of the three-step strategy considered in this article. The initial identification and characterisation of the compound in consumption products, the first reported metabolic pathway and the development of analytical methodologies for its determination (and/or their metabolites) in different toxicological samples are described. The analytical strategies and MS instruments are briefly discussed to show the reader the possibilities that MS instrumentation offer to analytical scientists. This publication aims to be a starting point for those interested on the NPS research field from an analytical chemistry point of view.

In vivo solid-phase microextraction swab-mass spectrometry for multidimensional analysis of human saliva

Solid phase microextraction (SPME) is one of the most powerful sample preparation techniques for analyte extraction and enrichment from complex matrices. SPME fibers are commonly used to extract analytes from collected samples. Following our recent work on development of in vivo SPME swab that integrates an SPME fiber and a medical swab (Anal Chim Acta, 2020, 1124, 71-77), the multiple SPME fibers inserted into a medical swab (multiple-SPME swab) is further developed to couple with different mass spectrometry (MS) approaches for multidimensional analysis of human saliva in this work. The new features of cotton ball and SPME fiber of multiple-SPME swab are investigated. Biomarker discovery and disease diagnosis using multiple-SPME swab are also demonstrated. The present study shows that direct coupling multiple-SPME swab with different MS-based approaches could be simple and versatile in vivo method to expand the classes of analytes extracted simultaneously from human saliva.

Advances in drugs of abuse testing

Drugs of abuse testing is widely used clinically and forensically. Urine is the preferred type of specimen for drugs of abuse screening, but saliva, sweat, hair, and meconium are emerging types of specimens. GC-MS has been used as a gold standard for confirmatory drug testing, but LC-tandem-MS can analyze more diverse types of analytes than GC-MS. Thus, LC-tandem-MS becomes a new gold standard for confirmatory drug testing. Unlike GC-MS, LC-tandem-MS is not suited for non-targeted comprehensive drug screening. But with the advent of high-resolution-MS such as Tof-MS, which can discriminate the compounds of similar molecular masses but with different formulas, LC-hybrid-Tof-MS is usable for non-targeted comprehensive drug screening. Another technical advancement is the advent of miniature ambient ionization MS, which can analyze biological specimens including urine within one minute. Thus these mass spectrometers are promising for rapid drugs of abuse testing in a POC setting.

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.

The current role of mass spectrometry in forensics and future prospects

Mass spectrometry (MS) techniques are highly prevalent in crime laboratories, particularly those coupled to chromatographic separations like gas chromatography (GC) and liquid chromatography (LC). These methods are considered "gold standard" analytical techniques for forensic analysis and have been extensively validated for producing prosecutorial evidentiary data. However, factors such as growing evidence backlogs and problematic evidence types (e.g., novel psychoactive substance (NPS) classes) have exposed limitations of these stalwart techniques. This critical review serves to delineate the current role of MS methods across the broad sub-disciplines of forensic science, providing insight on how governmental steering committees guide their implementation. Novel, developing techniques that seek to broaden applicability and enhance performance will also be highlighted, from unique modifications to traditional hyphenated MS methods to the newer "ambient" MS techniques that show promise for forensic analysis, but need further validation before incorporation into routine forensic workflows. This review also expounds on how recent improvements to MS instrumental design, scan modes, and data processing could cause a paradigm shift in how the future forensic practitioner collects and processes target evidence.

Direct and Fast Screening of New Psychoactive Substances Using Medical Swabs and Atmospheric Solids Analysis Probe Triple Quadrupole with Data-Dependent Acquisition

New psychoactive substances (NPS) have become a serious public health problem, as they are continuously changing their structures and modifying their potency and effects on humans, and therefore, novel compounds are unceasingly appearing. One of the major challenges in forensic analysis, particularly related to the problem of NPS, is the development of fast screening methodologies that allow the detection of a wide variety of compounds in a single analysis. In this study, a novel application of the atmospheric solids analysis probe (ASAP) using medical swabs has been developed. The swab-ASAP was coupled to a triple quadrupole mass analyzer working under a data-dependent acquisition mode in order to perform a suspect screening of NPS in different types of samples as well as on surfaces. The compounds were automatically identified based on the observed fragmentation spectra using an in-house built MS/MS spectra library. The developed methodology was applied for the identification of psychoactive substances in research chemicals and herbal blends. The sensitivity of the method, as well as its applicability for surface analysis, was also assessed by identifying down to 1 μg of compound impregnated onto a laboratory table. Another remarkable application was the identification of cathinones and synthetic cannabinoids on the fingers of potential consumers. Interestingly, our data showed that NPS could be identified on the fingers after being in contact with the product and even after cleaning their hands by shaking off with a cloth. The methodology proposed in this paper can be applied for routine analyses of NPS in different matrix samples without the need to establish a list of target compounds prior to analysis.

In vivo solid-phase microextraction swab sampling of environmental pollutants and drugs in human body for nano-electrospray ionization mass spectrometry analysis

In vivo sampling and sensitive detection of environmental pollutants and drugs in human body play a crucial role in understanding human health. In this study, in vivo solid-phase microextraction (SPME) swab was fabricated using a SPME fiber and a medical cotton swab for noninvasive sampling and extraction of environmental pollutants and drugs in human oral cavity, nasal cavity and on skin surface. After sampling, SPME was coupled with nano-electrospray ionization mass spectrometry (nanoESI-MS) for desorption, ionization, and detection of the extracted analytes. As a result, limit of detection (LOD) and limit of quantification (LOQ) of nicotine in oral fluid were found to be 1.0 pg/mL (S/N ≥ 3) and 4.0 pg/mL (S/N ≥ 10), respectively. Linear dynamic signal responses of nicotine exhibited excellent linearity (R² = 0.9996) in human oral fluid ranging from 0.1 to 50 ng/mL. The coefficient of variation (CV) values of SPME swab for five measurements from sample vials and human body were 5.1-6.7% and 22.7-32.6%, respectively. Rapid analysis of a single sample could be completed within 10 min. Overall, our results demonstrated that SPME swab-MS is a promising noninvasive method for enhanced detection of analytes in human body.

Application of probe electrospray ionization-tandem mass spectrometry to ultra-rapid determination of glufosinate and glyphosate in human serum

Glufosinate and glyphosate, which are non-selective herbicides that include an amino acid moiety in their structures, are frequently used worldwide to control unwanted vegetation. Unfortunately, these readily available herbicides are also used by people to commit suicide, and thus represent important chemicals of interest in the fields of clinical medicine and forensics. Because of the high water solubility of these herbicides, most analytical methods for their detection require a derivatization step, which results in longer analysis times. Therefore, derivatization-based methods do not currently contribute to judgements on treatment decisions in emergency medicine. In this study, we addressed this limiting factor by developing an ultra-rapid and simple analytical technique using a combination of probe electrospray ionization (PESI) and tandem mass spectrometry (MS/MS), which gives quantitative results within 0.3 min. Herbicide standards were added to human serum that was then subjected to analysis (N = 5 per concentration). The analysis was repeated daily over eight consecutive days. The limit of detection (LOD) was 0.59 μg/mL for glufosinate and 0.20 μg/mL for glyphosate. The limit of quantitation (LOQ), i.e., the lowest point on the calibration curves, was 1.56 μg/mL for both the herbicides. The matrix effects were observed at three different concentrations (between 95.7%-104% for glufosinate, and between 90.7%-95.7% for glyphosate). When applied to samples taken from actual poisoning cases (six samples for each herbicide), the present method gave almost the same quantitative values as those obtained by conventional high-performance liquid chromatography with fluorescence detection. Thus, we believe that PESI-MS/MS could emerge as a rapid diagnosis method in the clinical emergency field.

Oral Cavity Fluid as an Investigative Approach for Qualitative and Quantitative Evaluations of Drugs in Postmortem Subjects

A relatively overlooked aspect of forensic science is the potential of oral cavity fluid for contributing to a forensic diagnosis. Although traditional specimens, like blood and urine, are routinely evaluated for forensic toxicology testing, fluid from the oral cavity has not been investigated as a matrix in postmortem cases. Our laboratory developed and validated qualitative and quantitative analytical methods for determining 47 medicinal and illicit drugs from oral cavity fluid. These developed methods aimed to compare results from liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) analyses of oral cavity fluid to those of traditional matrices collected from the same postmortem subjects. Of 34 cadavers studied, 32 (including two decomposed and two drowned subjects) had detectable and quantifiable drugs in the oral cavity fluid and/or blood, urine, bile, vitreous fluid and/or liver tissue. The most significant finding was that 6-acetylmorphine (6-AM) was detected more frequently in oral cavity fluid (11 cases) than in blood and urine combined (6 cases). Compounds with a short window of detection, like the heroin metabolite, 6-AM and even heroin, could be detected more readily in oral cavity fluid than in urine. In 2017, the incidence of heroin-related overdose deaths increased to 15,958. Those data have shed light on the practicality of testing oral cavity fluid postmortem and its significance in forensic toxicology. In conclusion, this study showed that oral cavity fluid could be useful for detecting and quantifying drugs in postmortem subjects; moreover, oral cavity fluid may be particularly suitable when other matrices are limited or difficult to collect, due to body condition or putrefaction.

The Relevance of Mass Spectrometry Analysis for Personalized Medicine through Its Successful Application in Cancer "Omics"

Mass spectrometry (MS) is an essential analytical technology on which the emerging omics domains; such as genomics; transcriptomics; proteomics and metabolomics; are based. This quantifiable technique allows for the identification of thousands of proteins from cell culture; bodily fluids or tissue using either global or targeted strategies; or detection of biologically active metabolites in ultra amounts. The routine performance of MS technology in the oncological field provides a better understanding of human diseases in terms of pathophysiology; prevention; diagnosis and treatment; as well as development of new biomarkers; drugs targets and therapies. In this review; we argue that the recent; successful advances in MS technologies towards cancer omics studies provides a strong rationale for its implementation in biomedicine as a whole.

Direct coupling of solid phase microextraction with electrospray ionization mass spectrometry: A Case study for detection of ketamine in urine

Electrospray ionization mass spectrometry (ESI-MS) is a commonly used technique for analysis of various samples. Solid phase microextraction (SPME) is a simple and efficient technique that combines both sampling and sample preparation into one consolidated step, preconcentrating extracted analytes for ultra-sensitive analysis. Historically, SPME has been coupled with chromatography-based techniques for sample separation prior to analysis, however more recently, the chromatographic step has been omitted, with the SPME device directly coupled with the mass spectrometer. In this study, direct coupling of SPME with ESI-MS was developed, and extensively validated to quantitate ketamine from human urine, employing a practical experimental workflow and no extensive hardware modification to the equipment. Among the different fibers evaluated, SPME device coated with C₁₈/benzenesulfonic acid particles was selected for the analysis due to its good selectivity and signal response. Different approaches, including desorption spray, dripping, desorption ESI and nano-ESI were attempted for elution and ionization of the analytes extracted using the SPME fibers. The results showed that the desorption spray and nano-ESI methods offered better signal response and signal duration than the others that were evaluated. The analytical performance of the SPME-nano-ESI-MS setup was excellent, including limit of detection (LOD) of 0.027 ng/mL, limit of quantitation (LOQ) of 0.1 ng/mL, linear range of 0.1-500.0 ng/mL (R² = 0.9995) and recoveries of 90.8-109.4% with RSD 3.4-10.6% for three validation points at 4.0, 40.0 and 400.0 ng/mL, far better than the performance of conventional methods. The results herein presented, demonstrated that the direct coupling of SPME fibers with ESI-MS-based systems allowed for the simple and ultra-sensitive determination of analytes from raw samples such as human urine.

Rapid detection and quantitation of drugs-of-abuse by wooden-tip electrospray ionization mass spectrometry

Determination of drugs-of-abuse in body fluids of drug abusers is important for the law enforcement as well as the treatment and rehabilitation. In this study, wooden-tip electrospray ionization mass spectrometry (WT-ESI-MS), a simple and cost-effective technique, was developed for rapid detection and quantitation of common drugs-of-abuse, including methamphetamine, methylenedioxymethamphetamine (MDMA), cocaine, heroin and tetrahydrocannabinol (THC), in urine and oral fluid, following our previous successful demonstration for rapid and sensitive detection of ketamine and nor-ketamine in urine and oral fluid by this technique. It was found that the limit-of-detection for methamphetamine could fully fulfill the cut-off value requirements of the international standards, and those of MDMA and cocaine could fulfill some of the requirements. The linear range, accuracy and precision for quantitation of the drugs were generally satisfactory, except for THC for which the analytical performance still needs to be improved. Analysis of one sample could typically be completed within minutes. These results indicated that WT-ESI-MS could be used for rapid screening of drugs-of-abuse in urine, oral fluid as well as other body fluids.

Direct sampling mass spectrometry for clinical analysis

Direct sampling mass spectrometry (MS) has been advancing aggressively, showing immense potential in translating MS into the clinical field. Unlike traditional MS analysis involving extensive sample preparation and chromatographic separation, quick and simple procedures with minimal sample pretreatment or purification became available with direct sampling. An overview of the development in this field is provided, including some representative ambient ionization and fast extraction methods. Quantitative applications of these methods are emphasized and their efficacy are highlighted from a clinical aspect; non-quantitative applications in clinical analysis are also discussed. This review also discusses the integration of direct sampling MS with miniature mass spectrometers and its future outlook as an emerging clinical tool for point-of-care analysis.

Analysis of human gliomas by swab touch spray-mass spectrometry: applications to intraoperative assessment of surgical margins and presence of oncometabolites

Touch spray mass spectrometry using medical swabs is an ambient ionization technique (ionization of unprocessed sample in the open air) that has potential intraoperative application in quickly identifying the disease state of tissue and in better characterizing the resection margin. To explore this potential, we studied 29 human brain tumor specimens and obtained evidence that this technique can provide diagnostic molecular information that is relevant to brain cancer. Touch spray using medical swabs involves the physical sampling of tissue using a medical swab on a spatial scale of a few mm² with subsequent ionization occurring directly from the swab tip upon addition of solvent and application of a high voltage. Using a tertiary mixture of acetonitrile, N,N-dimethylformamide, and ethanol, membrane-derived phospholipids and oncometabolites are extracted from the tissue, incorporated into the sprayed microdroplets, vacuumed into the mass spectrometer, and characterized in the resulting mass spectra. The tumor cell load was assessed from the complex phospholipid pattern in the mass spectra and also separately by measurement of N-acetylaspartate. Mutation status of the isocitrate dehydrogenase gene was determined via detection of the oncometabolite 2-hydroxyglutarate. The lack of sample pretreatment makes touch spray mass spectrometry using medical swabs a feasible intraoperative strategy for rapid surgical assessment.

New Advances in Toxicological Forensic Analysis Using Mass Spectrometry Techniques

This article reviews mass spectrometry methods in forensic toxicology for the identification and quantification of drugs of abuse in biological fluids, tissues, and synthetic samples, focusing on the methodologies most commonly used; it also discusses new methodologies in screening and target forensic analyses, as well as the evolution of instrumentation in mass spectrometry.

Fatty Acid Patterns Detected By Ambient Ionization Mass Spectrometry in Canine Invasive Urothelial Carcinoma From Dogs of Different Breeds

Background:

In early work ambient ionization mass spectrometry (MS) revealed lipid patterns distinguishing muscle invasive bladder cancer (invasive urothelial carcinoma, InvUC) from normal urothelium. A new ambient ionization MS approach, touch spray MS (TS-MS) can rapidly generate mass spectra in real time, potentially in a point-of-care setting. A tissue sample removed from a patient is touched by a probe, and mass spectra generated within seconds.

Objective:

To validate TS-MS methods using specimens from naturally-occurring InvUC in dogs where the cancer closely mimics the human condition, and to demonstrate proof-of-concept that TS-MS can elucidate lipid patterns distinguishing InvUC from normal urothelium.

Methods:

Samples of normal urothelium and InvUC from dogs of several breeds were analyzed by TS-MS with correlative histopathology across each sample. Results were compared to those obtained with desorption electrospray ionization mass spectrometry (DESI-MS), a more traditional method. Data were analyzed by Principal Component Analysis and Linear Discriminant Analysis.

Results:

Lipid patterns identified by TS-MS, as well as by DESI-MS, differed between InvUC and normal urothelium with m/z 281.5 (oleic acid) and m/z 563.5 (oleic acid dimer) substantially contributing to the differences. Using histologic diagnosis as the gold standard, TS-MS had a global prediction rate of 93%.

Conclusions:

TS-MS can be used to identify lipid patterns that differentiate canine InvUC from normal urothelium. Optimization of TS-MS could lead to a point-of-care approach to distinguish cancer from normal in ex vivo tissues in real time, and to define biochemical processes leading to cancer development and progression.

Direct ion generation from swabs

Medical swabs are used for biofluid and tissue sampling in clinical applications. The use of medical swabs as electrospray ionization probes for direct mass spectrometric analysis is a novel and potentially widely applicable development. Here we discuss ion generation, characterize ionization behavior via microscopic videography and describe some illustrative examples of applications.

Coated blade spray: shifting the paradigm of direct sample introduction to MS

Coated blade spray (CBS) is a solid-phase microextraction-based technology that can be directly coupled to MS to enable the rapid qualitative and quantitative analysis of complex matrices. The goal of this mini review is to concisely introduce CBS's operational fundamentals and to consider how it correlates/contrasts with existing direct-to-MS technologies suitable for bioanalytical applications. In addition, we provide a fair comparison of CBS to other existing solid-phase microextraction-to-MS approaches, as well as an overview of recent CBS applications/strategies that have been developed to analyze diverse compounds present in biofluids.

Simultaneous and Sequential MS/MS Scan Combinations and Permutations in a Linear Quadrupole Ion Trap

Methods of performing precursor ion scans as well as neutral loss scans in a single linear quadrupole ion trap have recently been described. In this paper we report methodology for performing permutations of MS/MS scan modes, that is, ordered combinations of precursor, product, and neutral loss scans following a single ion injection event. Only particular permutations are allowed; the sequences demonstrated here are (1) multiple precursor ion scans, (2) precursor ion scans followed by a single neutral loss scan, (3) precursor ion scans followed by product ion scans, and (4) segmented neutral loss scans. (5) The common product ion scan can be performed earlier in these sequences, under certain conditions. Simultaneous scans can also be performed. These include multiple precursor ion scans, precursor ion scans with an accompanying neutral loss scan, and multiple neutral loss scans. We argue that the new capability to perform complex simultaneous and sequential MSⁿ operations on single ion populations represents a significant step in increasing the selectivity of mass spectrometry.

Medical Swab Analysis Using Desorption Electrospray Ionization Mass Spectrometry: A Noninvasive Approach for Mucosal Diagnostics

Medical swabs are routinely used worldwide to sample human mucosa for microbiological screening with culture methods. These are usually time-consuming and have a narrow focus on screening for particular microorganism species. As an alternative, direct mass spectrometric profiling of the mucosal metabolome provides a broader window into the mucosal ecosystem. We present for the first time a minimal effort/minimal-disruption technique for augmenting the information obtained from clinical swab analysis with mucosal metabolome profiling using desorption electrospray ionization mass spectrometry (DESI-MS) analysis. Ionization of mucosal biomass occurs directly from a standard rayon swab mounted on a rotating device and analyzed by DESI MS using an optimized protocol considering swab-inlet geometry, tip-sample angles and distances, rotation speeds, and reproducibility. Multivariate modeling of mass spectral fingerprints obtained in this way readily discriminate between different mucosal surfaces and display the ability to characterize biochemical alterations induced by pregnancy and bacterial vaginosis (BV). The method was also applied directly to bacterial biomass to confirm the ability to detect intact bacterial species from a swab. These results highlight the potential of direct swab analysis by DESI-MS for a wide range of clinical applications including rapid mucosal diagnostics for microbiology, immune responses, and biochemistry.

Medical swab touch spray-mass spectrometry for newborn screening of nicotine and cotinine in meconium

Newborn screening is one of public health concerns designed to screen infants shortly after birth. Prenatal exposure to tobacco smoke such as nicotine has been reported to affect babies. Levels of nicotine and cotinine in meconium were widely used to evaluate the tobacco exposure of foetuses during pregnancy in a polluted environment. In this study, medical swabs were applied by using touch spray-mass spectrometry (TS-MS) to collect meconium from newborn infants for detection of nicotine and cotinine. Parameters such as choice of spray solvents, solvent volume and collision energy for screening of nicotine and cotinine were optimized. The limits of detection, reproducibility and matrix effect for analysis of meconium were also investigated. In this study, the levels of nicotine and cotinine in 54 puerpera volunteers were screened by TS-MS and were validated by using traditional liquid chromatography-mass spectrometry. These results showed that medical swab TS-MS would be useful for newborn screening of nicotine and cotinine in meconium with high reproducibility, speed, sensitivity and specificity. The use of disposable medical swabs involves no sample preparation and no chromatographic separation, significantly reducing the cost and time required for screening a large number of clinical sample. Copyright © 2016 John Wiley & Sons, Ltd.

Quantitative determination of methamphetamine in oral fluid by liquid-liquid extraction and gas chromatography/mass spectrometry

Methamphetamine abuse is one of the most medical and social problems many countries face. In spite of the ban on the use of methamphetamine, it is widely available in Iran's drug black market. There are many analytical methods for the detection of methamphetamine in biological specimen. Oral fluid has become a popular specimen to test for the presence of methamphetamine. The purpose of the present study was to develop a method for the extraction and detection of methamphetamine in oral fluid samples using liquid-liquid extraction (LLE) and gas chromatography/mass spectrometry (GC/MS) methods. An analytical study was designed in that blank and 50 authentic oral fluid samples were collected to be first extracted by LLE and subsequently analysed by GC/MS. The method was fully validated and showed an excellent intra- and inter-assay precision (reflex sympathetic dystrophy ˂ 10%) for external quality control samples. Recovery with LLE methods was 96%. Limit of detection and limit of quantitation were 5 and 15 ng/mL, respectively. The method showed high selectivity, no additional peak due to interfering substances in samples was observed. The introduced method was sensitive, accurate and precise enough for the extraction of methamphetamine from oral fluid samples in forensic toxicology laboratories.

Ionization Suppression and Recovery in Direct Biofluid Analysis Using Paper Spray Mass Spectrometry

Paper spray mass spectrometry is a method for the direct analysis of biofluid samples in which extraction of analytes from dried biofluid spots and electrospray ionization occur from the paper on which the dried sample is stored. We examined matrix effects in the analysis of small molecule drugs from urine, plasma, and whole blood. The general method was to spike stable isotope labeled analogs of each analyte into the spray solvent, while the analyte itself was in the dried biofluid. Intensity of the labeled analog is proportional to ionization efficiency, whereas the ratio of the analyte intensity to the labeled analog in the spray solvent is proportional to recovery. Ion suppression and recovery were found to be compound- and matrix-dependent. Highest levels of ion suppression were obtained for poor ionizers (e.g., analytes lacking basic aliphatic amine groups) in urine and approached -90%. Ion suppression was much lower or even absent for good ionizers (analytes with aliphatic amines) in dried blood spots. Recovery was generally highest in urine and lowest in blood. We also examined the effect of two experimental parameters on ion suppression and recovery: the spray solvent and the sample position (how far away from the paper tip the dried sample was spotted). Finally, the change in ion suppression and analyte elution as a function of time was examined by carrying out a paper spray analysis of dried plasma spots for 5 min by continually replenishing the spray solvent. Graphical Abstract ᅟ.