Direct Analysis of Amphetamine Stimulants in a Whole Urine Sample by Atmospheric Solids Analysis Probe Tandem Mass Spectrometry

Analysis of 15 anti-obesity drugs in urine using thermal-assisted paper spray mass spectrometry

Anti-obesity drugs, used to suppress appetite and reduce fat absorption, have been circulated and traded illegally worldwide. The traditional methods of liquid chromatography tandem mass spectrometry (LC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) for analyzing these drugs in in vivo samples require complex sample pretreatment and time-consuming procedures. To address this issue, a thermal-assisted paper spray mass spectrometry (PS-MS) method was developed in this study to analyze anti-obesity drugs in raw urine. By incorporating a heat source and optimizing the spray solvent and paper substrate, this technique demonstrates reduced matrix effect and higher sensitivity compared to traditional PS-MS methodology for direct analysis of anti-obesity drugs in urine samples. A temperature range of 100-200 °C can be set for screening anti-obesity drugs in urine samples, with the flexibility to adjust the temperature according to the specific drug being analyzed. The limits of detection (LODs) for these 15 anti-obesity drugs in urine ranged between 1 and 500 ng mL-1. Furthermore, the thermal-assisted PS-MS method exhibited good linearities (R2, 0.9903-0.9997) within the range from 10-100 to 1000 ng mL-1 for the direct quantitation of anti-obesity drugs in urine samples with an internal standard. Therefore, the thermal-assisted PS-MS technique may provide a novel approach for the direct analysis of drugs in complex samples.

Impact of Ambient Vapors on Spectra of 4-Nitroaniline Recorded under Atmospheric Solids Analysis Probe (ASAP) Mass Spectrometric Conditions

Thermally desorbed 4-nitroaniline (4-NA), upon atmospheric pressure chemical ionization (APCI), generates gaseous ions for its protonated species. The APCI mass spectrum recorded under mild in-source ion-activating conditions from 4-NA showed a peak at m/z 139, whereas that acquired under high ion-activating conditions showed two additional peaks at m/z 122 (^•OH loss) and 92 (^•NO loss). The spectrum changed instantaneously when acetonitrile vapor was introduced to the source. In the new spectrum, both m/z 122 and 92 peaks were absent, while a new peak appeared at m/z 93. Ion-mobility separation carried out with the m/z 139 ion revealed that the initial ion represented the thermodynamically favored nitro-protonated tautomer. The ion population changed to an ensemble dominated by the less-favored amino-protomer when acetonitrile vapor was introduced to the ion source. The amino-protomer, upon collisional activation, loses ^•NO₂ to generate an m/z 93 ion, which was confirmed to be the 4-dehydroanilinium ion. Ion mobility provided a practical way to monitor the changes secured by acetonitrile vapor because the two protomers showed different arrival times. Under spray-ionization conditions, the formation of the thermodynamically less favored protomer has been attributed to kinetic trapping. Our study demonstrated that the less favored amino-protomer could be generated by introducing acetonitrile vapor under nonspray conditions. Apparently, under APCI conditions, protonated water vapor attaches to the nitro group to generate a proton-bound heterodimer, which upon activation dissociates to yield the nitro-protomer. In contrast, protonated acetonitrile makes a tighter complex preferentially with the amino group, which upon activation breaks to the amino-protomer.

Ambient ionization mass spectrometry applied to new psychoactive substance analysis

In the past decade a plethora of drugs with similar effects to controlled psychoactive drugs, like cannabis, amfetamine (amphetamine), or lysergic acid diethylamide, have been synthesized. These drugs can collectively be classified under the term new psychoactive substances (NPS) and are used for recreational purposes. The novelty of the substances, alongside the rapid rate of emergence and structural variability, makes their detection as well as their legal control highly challenging, increasing the demand for rapid and easy-to-use analytical techniques for their detection and identification. Therefore, interest in ambient ionization mass spectrometry applied to NPS has grown in recent years, which is largely because it is relatively fast and simple to use and has a low operating cost. This review aims to provide a critique of the suitability of current ambient ionization techniques for the analysis of NPS in the forensic and clinical toxicology fields. Consideration is given to analytical performance and ease of implementation, including ionization efficiency, selectivity, sensitivity, quantification, analyte chemistry, molecular coverage, validation, and practicality.

Ambient Ionization Mass Spectrometry: Application and Prospective

Mass spectrometry (MS) is a formidable analytical tool for the analysis of non-polar to polar compounds individually and/or from mixtures, providing information on the molecular weights and chemical structures of the analytes. During the last more than one-decade, ambient ionization mass spectrometry (AIMS) has developed quickly, producing a wide range of platforms and proving scientific improvements in a variety of domains, from biological imaging to quick quality control. These methods have made it possible to detect target analytes in real time without sample preparation in an open environment, and they can be connected to any MS system with an atmospheric pressure interface. They also have the ability to analyze explosives, illicit drugs, disease diagnostics, drugs in biological samples, adulterants in food and agricultural products, reaction progress, and environmental monitoring. The development of novel ambient ionization techniques, such as probe electrospray ionization, paper spray ionization, and fiber spray ionization, employed even at picolitre to femtolitre solution levels to provide femtogram to attogram levels of the target analytes. The special characteristic of this ambient ion source, which has been extensively used, is the noninvasive property of PESI of examination of biological real samples. The results in the current review supports the idea that AIMS has emerged as a pioneer in MS-based approaches and that methods will continue to be developed along with improvements to existing ones in the near future.

Simplified screening approach of anabolic steroid esters using a compact atmospheric solid analysis probe mass spectrometric system

Due to the absence of chromatographic separation, ambient ionization mass spectrometry had the potential to improve the throughput of control laboratories in the last decades and will soon be an excellent approach for on-site use as well. In this study, an atmospheric solids analysis probe (ASAP) with a single quadrupole mass analyzer has been evaluated to identify anabolic steroid esters rapidly. Sample introduction, applied scan time, and probe temperature were optimized for sensitivity. The in-source fragmentations of seventeen selected steroid esters, commonly found in illicit samples, were determined by applying different cone voltages (12, 20, 30, and 40 V). A spectral library was created for these steroid esters based on the four stages of in-source fragmentation spectra. The applicability of this method was demonstrated for the rapid identification of steroid esters in oily injection solutions, providing test results in less than 2 min.

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.

Rapid, in situ detection of chemical warfare agent simulants and hydrolysis products in bulk soils by low-cost 3D-printed cone spray ionization mass spectrometry

Chemical warfare agents (CWAs) are toxic chemicals that have been used as disabling or lethal weapons in war, terrorist attacks, and assasinations. The Chemical Weapons Convention (CWC) has prohibited the use, development, production, and stockpiling of CWAs since its initiation in 1997, however, the threat of deployment still looms. Detection of trace CWAs post-deployment or post-remediation, in bulk matrices such as soil, often requires lengthy sample preparation steps or extensive chromatographic separation times. 3D-printed cone spray ionization (3D-PCSI), an ambient ionization mass spectrometric (MS) technique, provides a rapid, simple, and low-cost method for trace CWA analysis in soil matrices for both in-laboratory and in-field detection. Described here is the utilization of conductive 3D-printed cones to perform both rapid sampling and ionization for CWA simulants and hydrolysis products in eight solid matrices. The analysis of trace quantities of CWA simulants and hydrolysis products by 3D-PCSI-MS coupled to both a commercial benchtop system and a field-portable MS system is detailed. Empirical limits of detection (LOD) for CWA simulants on the benchtop MS ranged from 100 ppt to 750 ppb and were highly dependant on solid matrix composition, with the portable system yielding similar spectral data from alike matrices, albeit with lower sensitivity.

Development of surface ionization mass spectrometry for detection of stimulants in human urine

This paper demonstrates direct detection of stimulants such as amphetamine, methamphetamine and cocaine spiked with untreated urine and a real world sample using surface ionization mass spectrometry. Spiked samples were analyzed without preliminary chromatographic separation and extraction procedure using the developed method. Moreover, in order to check the analytical capabilities of the method non-extracted real world sample was analyzed. After liquid-liquid extraction, the same sample was analyzed using the method for comparative study. Limit of detection of spiked samples was in the range of 10 pg (10 ng/ml) to 100 pg (100 ng/ml). Linear ranges of samples were two orders of magnitude or more than two orders of magnitude. It was revealed these spiked samples and real world sample can be analyzed without preliminary chromatographic separation and preliminary extraction procedure due to high selectivity of the method and the presence of the indicator lines of studied analytes in the mass spectra. The surface ionization mass spectrometry data was attested by the GC/MS analysis of these samples.

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.

Utilization of atmospheric solids analysis probe mass spectrometry for analysis of fatty acids on seed surface

Atmospheric solids analysis probe mass spectrometry (ASAP-MS) was used for the first time for direct surface analysis of plant material. It can be readily used for surface analysis of whole and intact pea seeds and their seed coats, and for the study of the profile of fatty acids on the outer surface. Furthermore, ASAP-MS in combination with multivariate statistics allowed classification of pea genotypes with respect to physical dormancy and investigation of related biological markers. Hexacosanoic and octacosanoic acids were suggested to be important markers likely influencing water transport through the seed coat into the embryo (with the highest significance for dormant L100 genotype). ASAP-MS provided higher selectivity and better signal of fatty acids compared to (MA)LDI-MS (laser desorption ionization mass spectrometry either matrix free or matrix assisted) providing on the other hand spatial distribution information and results obtained by both methods are mutually supportive. The developed ASAP-MS method and obtained results can be widely utilized in biological, food, and agricultural research. Graphical abstract ᅟ.

Atmospheric Solid Analysis Probe and Modified Desorption Electrospray Ionization Mass Spectrometry for Rapid Screening and Semi-Quantification of Zilpaterol in Urine and Tissues of Sheep

Ambient ionization mass spectrometric methods including desorption electrospray ionization (DESI) and atmospheric solid analysis probe (ASAP) have great potential for applications requiring real-time screening of target molecules in complex matrixes. Such techniques can also rapidly produce repeatable semiquantitative data, with minimal sample preparation, relative to liquid chromatography-mass spectrometry (LC-MS). In this study, a commercial ASAP probe was used to conduct both ASAP-MS and modified DESI (MDESI) MS analyses. We conducted real-time qualitative and semiquantitative analysis of the leanness-enhancing agent zilpaterol in incurred sheep urine, kidney, muscle, liver, and lung samples using ASAP-MS and MDESI MS. Using ASAP, limits of detection (LOD) and quantitation (LOQ) in urine were 1.1 and 3.7 ng/mL, respectively, while for MDESI MS they were 1.3 and 4.4 ng/mL, respectively. The LODs for tissues were 0.1-0.4 ng/g using ASAP, and 0.2-0.6 ng/g with MDESI MS. The LOQs of the tissues in ASAP were 0.4-1.2 ng/g and 0.5-2.1 ng/g in MDESI MS. Trace levels of zilpaterol were accurately analyzed in urine and tissues of sheep treated with dietary zilpaterol HCl. The correlation coefficient ( R²) between semiquantitative ASAP-MS and MDESI MS results of urine samples was 0.872. The data from ASAP and MDESI MS were validated using LC-MS/MS; urinary zilpaterol concentrations ≥5.0 ng/mL or tissue zilpaterol concentrations ≥1.5 ng/g were detected by ASAP and MDESI MS, respectively, 100% of the time. Forty samples could be analyzed in triplicate, directly from biological matrixes in under an hour.

Rapid analysis of forensic-related samples using two ambient ionization techniques coupled to high-resolution mass spectrometers

RATIONALE

This paper highlights the versatility of interfacing two ambient ionization techniques, Laser Diode Thermal Desorption (LDTD) and Atmospheric Solids Analysis Probe (ASAP), to high-resolution mass spectrometers and demonstrate the method's capability to rapidly generate high-quality data from multiple sample types with minimal, if any, sample preparation.

METHODS

For ASAP-MS analysis of solid and liquid samples, the material was transferred to a capillary surface before being introduced into the mass spectrometer. For LDTD-MS analysis, samples were solvent extracted, spotted in a 96-well plate, and the solvent was evaporated before being introduced into the mass spectrometer. All analyses were performed using Atmospheric Pressure Chemical Ionization in positive mode.

RESULTS

Seven consumer "Spice" packets were combined and analyzed by both ASAP and LDTD, which identified 11 synthetic cannabinoids/cathinones by full MS and MS/MS experiments. To further show the usefulness of these techniques, black tar heroin was analyzed, which resulted in the identification of heroin and its impurities (monoacetylmorphine, papaverine, and noscapine). These experiments were performed on the LTQ-Orbitrap to demonstrate the ability to perform both parallel and serial MS and MSⁿ experiments.

CONCLUSIONS

Interfacing LDTD and ASAP to high-resolution mass spectrometers allows for expeditious analysis of a wide range of samples, with minimal or no sample preparation. Both allow for rapid full scan, MS/MS, and/or MSⁿ experiments from a single sample introduction. Published in 2017. This article is a U.S. Government work and is in the public domain in the USA.