Plasmion at ASMS
Plasmion is grateful for the opportunity to have participated in the ASMS conference 2024 from June 2–6 in Anaheim, California!
It was a brilliant event to discuss mass spectrometry, and exchange innovations and new ideas. We proudly presented our SICRIT ion source at our booth (spot 235) and at the Agilent Hospitality Suite, where we also showcased the new version of our HaVoc Sensory System. Thank you to everyone who visited us and engaged in scientific discussions!
We are proud to have had poster presentations about the latest projects with SICRIT, which many of you attended. Below, you can find summaries of these presentations.
We look forward to seeing you next year!
Poster Presentations & Talks:
MONDAY, JUNE 03
SICRIT-HRMS for Metabolic Profiling through Direct Breath Analysis
MP 004, Jan-Christoph Wolf
SICRIT-HRMS for Metabolic Profiling through Direct Breath Analysis
Mass spectrometry has become an essential tool to characterize pesticides and their metabolites, when coupled to liquid chromatography or gas chromatography. However, it remains a challenging task to detect the compound of interest in complex matrix at trace level. Many improvements in limit of detection can be attributed to technology advancements driven by various research groups and vendors. The ionization efficiency is a major factor for sensitivity no matter what ion sources are employed. Recently, we noticed that an ion source, Soft Ionization by Chemical Reaction In Transfer (SICRIT) based on dielectric barrier discharge ionization has been commercialized by Plasmion LLC. This work is to evaluate the applications and scope of this tool in the crop protection field.
Methods
All the experiments were conducted on a Sciex QTRAP 6500 mass spectrometer system. The SICRIT interface with proper mounting bracket was obtained from Plasmion. Method parameters were adjusted to accommodate differences in samples and variation of HPLC conditions for optimal results. These parameters typically consist of voltage, frequency, and temperature of the SICRIT source, and gas flows and collision parameters of the MS. Most data were acquired in full scan mode with mass range adjusted to cover precursor ions. During the initial familiarization stage, samples were directly infused with syringe pump for quick optimization and troubleshooting purposes. Later, samples were introduced either through flow injection or liquid chromatography (condition details will be presented with the results).
Preliminary Data
We have screened a series of compounds with various structure motifs including thiazoles, pyridines, hydrazines, pyrimidines, 7‑ethoxycoumarin (7‑EC), thyroid hormones, steroid hormones, and short chain aliphatic acids. The thiazoles, pyridines, and hydrazines typically showed moderate to significant sensitivity increase when using the SICRIT source compared to equivalent ESI conditions (i.e. similar or same gas parameters, and same analyzer and detector parameters). Other compounds including aliphatic acids, 7‑EC, and small molecule hormones have given mixed results with an equivalent signal at best and little to no signal at worst. We will continue to optimize conditions to investigate the advantages and limitations of the tool. Other works include the investigation of solvent effects, additive effects, and matrix effects etc.
Novel Aspect
The work demonstrated the applications and scope of the SICRIT ion source for the detection of small molecule organic compounds.
Portable Mass Spectrometer with Dielectric Barrier Discharge Ionization for the Direct Analysis of Controlled Substancesand Explosives
MP 011, Taylor Hayward
Portable Mass Spectrometer with Dielectric Barrier Discharge Ionization for the Direct Analysis of Controlled Substancesand Explosives
Rapid and accurate detection of controlled substances and explosives is crucial for public health, safety, and the efficiency of law enforcement efforts. Utilizing mass spectrometry with ambient ionization, such as the dielectric barrier discharge ionization source, provides a viable method for real-time analysis. Thermal desorption is employed to swiftly introduce liquid and solid samples, vaporizing analytes before ionization to minimize matrix effects. Advances in miniaturization and portable mass spectrometry enable swift screening, assisting law enforcement in timely intervention and harm prevention. This comprehensive approach not only deters illicit activities but also enhances overall public health and safety, furnishing immediate evidence for streamlined legal processes.
Methods
A dielectric barrier discharge ionization source (SICRIT, Plasmion) was seamlessly integrated with a portable mass spectrometer (Continuity, BaySpec) through an interface, facilitating a continuous flow of ambient air for sampling and ionization. Liquid samples containing controlled substance and explosive standards were introduced into the thermal desorber attached to the SICRIT device, swiftly vaporizing them for gas-phase ionization. Positive and negative ionization modes were selectively employed based on the analytes of interest. Substance confirmation relied on internal libraries and tandem mass spectrometry, utilizing fragmentation patterns. This setup ensures efficient and precise analysis, enhancing the instrument’s capability to identify and confirm substances rapidly and accurately.
Preliminary Data
Ionization of specific controlled substances and explosives using the dielectric barrier discharge ionization source generated distinctive precursor ions, subsequently compared with a pre-established spectral library. Using the method described above single-digit nanogram amounts of targeted analytes were successfully detected, including controlled substances like cocaine, MDMA, methamphetamine, and fentanyl, as well as explosives including TNT, RDX, HMX, and PETN. Notably, the system exhibited a linear response over a minimum of three orders of magnitude. Moreover, accurate identification of mixtures containing multiple compounds was achieved without the need for chromatographic separation, facilitating rapid and efficient sample analysis. This approach demonstrates the method’s robustness and versatility in the detection of a diverse range of substances.
Novel Aspect
Qualitative and quantitative detection of controlled substances and explosives with a portable mass spectrometer and dielectric barrier discharge ionization.
TUESDAY, JUNE 04
Evaluation of Dielectric Barrier Discharge Ionization (DBDI) for the Identification of Xenobiotic Environmental Metabolites and Degradation Products
MP 194, Jeffrey Gilbert
Evaluation of Dielectric Barrier Discharge Ionization (DBDI) for the Identification of Xenobiotic Environmental Metabolites and Degradation Productsontrolled Substancesand Explosives
Identification of xenobiotic metabolites is a requirement for the registration of agrochemicals around the world. Decreasing application rates, an increasing number of required regulatory studies, and a lack of extraction/purification methods often create challenges for the identification of these metabolites using mass spectrometry. In addition, these trace level metabolites can often produce electrospray (ESI) or atmospheric pressure chemical ionization (APCI) spectra with low molecular ion signal intensity for conclusive identification. To address this challenge, we will present an evaluation of the performance of a Dielectric Barrier Discharge Ionization (DBDI) using a ‘Soft Ionization by Chemical Reaction in Transfer (Sicrit®) source across a small molecule library to help improve our understanding of the role that DBDI can play in metabolite identification.
Methods
A soft Ionization by chemical reaction in Transfer (Sicrit®) source was evaluated vs. a conventional ESI and APCI sources on a Thermo Q Exactive+ quadrupole-orbitrap liquid chromatography (LC/MS) system. The library compounds of interests were prepared at approximately 10 ug/ml (10ppm) concentrations, and analyzed using reverse-phase gradient liquid chromatography (LC) on a Shimadzu Nextera X2 binary LC. Positive and negative DBDI MS and MS/MS spectra were acquired under typical operating parameters for the Sicrit® source of [15 kV DC current at 15 kHz on the electrode, while heating the SPME liner to 500°C].
Preliminary Data
In this poster we describe the results of comparing DBDI ionization with ESI for a series of challenging environmental compounds, and across a library of over 1,000 small molecules. Both positive and negative DBDI and ESI MS and MS/MS spectra were evaluated for these library compounds using normal LC/MS operating conditions. The resulting MS and MS/MS spectra will be discussed based on observation of molecular ion adducts, fragment ions, etc. that can make them most useful for structural elucidation. Data analysis will include feature detection, adduct identification and relative peak integration using Compound Discoverer. Importantly, we can add various adducts unique to DBDI to the adduct list, ensuring proper peak integration. Another critical analytical property we will monitor in an automated fasion using CD is chromatographic S/N. Early data supports a significant S/N improvement when moving to methanol mobile phases that we will explore more.We plan to calculate various common chemical properties (pKa, total molecular surface area, number of basic atoms) and will attempt to relate those properties to correlations with DBDI. Additionally, using cheminformatics tools we hope to identify common chemical functional groups that are especially sensitive to DBDI. The goal of this work is to gain a better understanding of how to predict when DBDI will be likely to produce an intact molecular ion for compounds which generally produce only fragment ion species (i.e. protonation with water loss) using ESI.
Novel Aspect
Comparison of DBDI vs ESI ionization mass spectrometry for the detection and structure elucidation of environmental metabolites using LC/MS.
Overcoming Sampling Challenges in Analyzing Retained Tea Flavor Using Soft Ionization by Chemical Reaction in Transfer (SICRIT)
TP 119, Xinwei Feng
Overcoming Sampling Challenges in Analyzing Retained Tea Flavor Using Soft Ionization by Chemical Reaction in Transfer (SICRIT)
The flavor profile of tea is a complex interplay of various chemical compounds. Notably, the flavor retained in the tea cup after brewing offers a unique and delightful sensory experience. However, analyzing these retained flavors presents a unique challenge due to their complexity and the difficulty in sampling. This study employs Soft Ionization by Chemical Reaction in Transfer (SICRIT) in conjunction with High-Resolution Mass Spectrometry to overcome these challenges, providing a novel perspective on the flavor analysis of post-brewing tea.
Methods
Tea was brewed in a standard cup and consumed in a typical manner. The cup without further treatment has the retained flavors. These samples were analyzed using a Thermo LTQ Orbitrap equipped with a SICRIT ion source, a soft ionization technique that minimizes loss of flavors and allows for the detection and analysis of volatile compounds, making it particularly suitable for challenging sampling situations.
Preliminary Data
Initial analysis revealed a distinct difference between the flavor profile of the retained flavor in the tea cup and the original tea soup. Volcano plots indicated that the retained flavor contained high intensities of two specific chemicals (6‑Methyl-5-hepten-2-one and β‑damascenone). These chemicals were found to have a positive and joyful impact on the flavor profile, significantly contributing to the residual sensory experience of tea. Further analysis is ongoing to fully characterize these compounds and theirspecific contributions to the overall sensory experience. We would like to express our gratitude to ASPEC Technologies for their support in this research. Special thanks to Jiang Zhou and Wen Zhou from the Analytical Instrumental Center of Peking University for their invaluable contributions to this study.
Novel Aspect
Use of SICRIT and HRMS to analyze the retained flavors in post-brewing tea cup, revealing the most contributed chemicals.
GC-SICRIT-MS for Rapid Chemical Analysis of Electronic Cigarette Liquid
TP 020, Xiaoqing Wang
THURSDAY, JUNE 06
Illicit Drug Desorption and Chemical Profiling of Fingerprints using SICRIT Ion Source: A Rapid Analysis Approach
ThP 280, Ciara Conway
Illicit Drug Desorption and Chemical Profiling of Fingerprints using SICRIT Ion Source: A Rapid Analysis Approach
Forensic toxicology is a multi-disciplinary field that encompasses a variety of analyses, from biological sample differentiation to illicit analyte identification. In order to analyze the variety, there are various sample preparation techniques that can be time-consuming, requiring multiple analytical instruments. The focus of this study centers around fingerprints and how to conduct targeted and non-targeted analysis of analytes on this complex matrix by combining novel instrumental and computational approaches. With recent advancements in ambient ionization mass spectrometry (MS), plasma-based dielectric barrier discharge ionization (DBDI) sources, such as the SICRIT Ion Source, have been demonstrated to cover a wide range of these analytes. This ionization source, in combination with thermal desorption sampling allows for a rapid analysis while minimizing sample prep.
Methods
Standards (Polar and Non-Polar Lipids, Fentanyl, Cocaine, Heroin) and Fingerprints, underwent thermal desorption using a custom-built device flushed with dry nitrogen, excluding surrounding air. The desorbed samples were ionized by a SICRIT ionization source. Detection and quantification utilized a high-resolution LTQ Orbitrap XL mass spectrometer with specified parameters. Extracted ion chromatograms (EICs) were processed with Xcalibur for calibration curves and LOD calculation. Lipidomic samples, standards, and fingerprints underwent processing using an R‑script and Python machine learning pipeline. The pipeline involved dimension reduction methods, classifiers, and cross-validation grid search to identify optimal models for differentiating individuals based on their spectral data, showcasing potential applications in forensic analysis.
Preliminary Data
The study employed a high-resolution mass spectrometer to identify unknown compounds based on exact mass, focusing on three drugs (Fentanyl, Heroin, Cocaine) in varying absolute amounts. Direct thermal desorption of samples, completed in just 2 minutes, revealed ionization of all three compounds as protonated molecules. The limit of detection (LOD) for pure substances and spiked fingerprints, even with a complex matrix of lipids and amino acids, demonstrated sensitivity suitable for detecting trace amounts found in forensic samples. Although manual sample introduction and instrument limitations led to relatively high relative standard deviations (RSDs), the sensitivity was deemed sufficient for qualitative or semi-quantitative measurements. The technology’s forensic potential expanded to differentiate individuals based on chemical fingerprint profiles, proving effective even for non-volatile compounds like lipids. Principal component analysis (PCA) and a machine learning pipeline demonstrated the ability to distinguish fingerprints from different individuals, even across multiple days, with promising accuracy. The study concludes that this ambient ionization technique has potential forensic applications, offering rapid and effective differentiation of individuals based on chemical composition, particularly in cases involving smeared fingerprints on crime scenes. Further investigation with diverse demographics and extended time frames is recommended to explore its suitability for broader forensic use and comparisons with public databases. The ability to assign smeared fingerprints to potential suspects presents a valuable tool for forensic applications, showcasing the technique’s potential impact in crime scene analysis.The study introduces a thermal desorption SICRIT Ionization setup for rapid forensic sample analysis, identifying drugs in fingerprints within 2 min. The method is suitable for mobile systems, offers low power consumption, and enables personalized fingerprint identification, beneficial for smeared prints. Thermal desorption SICRIT-MS provides comprehensive forensic information without complex preparation.
Novel Aspect
Study introduces a rapid SICRIT Ionization Desorption setup for forensic analysis, identifying analytes within minutes, ideal for mobile systems.
Flow modulated GCxGC in combination with atmospheric pressure mass spectroscopy using the SICRIT ionization source
Flow modulated GCxGC in combination with atmospheric pressure mass spectroscopy using the SICRIT ionization source
An ambient ionization source, SICRIT, has been developed that utilizes a plasma-based core to provide a dielectric barrier discharge ionization to gaseous analytes. The SICRIT ionization source directly attaches to the inlet of any atmospheric pressure MS, and can be combined with chromatographic techniques such as gas chromatography. These mass spectrometers have more powerful vacuum systems that can therefore handle higher flow rates than a typical GC-MS, making it a perfect fit for flow modulated GC×GC. Further, hydrogen can be used as a carrier gas without a loss in sensitivity.
Methods
A flow modulated GC×GC was coupled to both an LC-QTOF and triple quadrupole via the SICRIT ionization source for volatile analysis. Hydrogen is used as a carrier gas, with second dimension flow rates greater than 20 mL/min. The entire effluent is directed to the mass spectrometer for sensitive detection and identification of analytes. Various column combinations were used to demostrate the application range of this setup.
Preliminary Data
Hydrocarbon analysis was used to investigate the response characteristics of the GC×GC-SICRIT-MS instrumentation. At the highest acquisition rates, at leaks 5 points per peak in the modulation cuts were achieved. Further, the soft ionization allowed for parent ions on n‑alkanes to be observed, which was also demonstrated in a diesel analysis.
Novel Aspect
Comibination of ambient ionization to flow modulated GC×GC. All hydrogen flow directed to the MS.
Comparison of Exhaled Breath Condensate Markers Using Two Ionization Methods: Electrospray Ionization and Dielectric Barrier Discharge Ionization
MP 797, Tatiana Rodriguez
Evaluation of soft ionization by chemical reaction in transfer for the detection of small molecule organic compounds
MP 008, Chengli Zu