Dual Ambient Sampling Hollow Cathode Discharge Ionization-Mass Spectrometry System: An Approach for Detecting Explosives and Drugs of Abuse at Trace to Ultratrace Levels.

Detection of illicit compounds like explosives and drugs of abuse at trace levels is crucial to provide public security and health safety. A dual ambient sampling system hollow cathode discharge (HCD) ion source was developed to investigate its performance. Here, trinitrotoluene (TNT), trinitrobenzene (TNB), hexamethylene triperoxide diamine (HMTD), and triacetone triperoxide (TATP) as explosives and methamphetamine (MA) as drugs of abuse were taken as model compounds.

Mass Spectrometry Imaging Techniques: Non-Ambient and Ambient Ionization Approaches.

Molecular information can be acquired from sample surfaces in real time using a revolutionary molecular imaging technique called mass spectrometry imaging (MSI). The technique can concurrently provide high spatial resolution information on the spatial distribution and relative proportion of many different compounds. Thus, many scientists have been drawn to the innovative capabilities of the MSI approach, leading to significant focus in various fields during the past few decades.

A Facile Determination of Herbicide Residues and Its Application in On-Site Analysis.

Abuse of herbicides in food safety is a vital concern that has an influence on the sustainable development of the world. This work presents, a modified ionization method with separation of the sample and carrier gas inlets, which was utilized for efficient ionization and analyte transfer of herbicides in crops. The working parameters of voltage, injective distance, desorption temperature, and the carrier gas flow rate were optimized to achieve the high efficiency of the transfer and ionization of the analyte.

Oriented Self-assembly of Flexible MOFs Nanocrystals into Anisotropic Superstructures with Homogeneous Hydrogels Behaviors.

Building of metal-organic frameworks (MOFs) homogeneous hydrogels made by spontaneous crystallization remains a significant challenge. Inspired by anisotropically structured materials in nature, an oriented super-assembly strategy to construct micro-scale MOFs superstructure is reported, in which the strong intermolecular interactions between zirconium-oxygen (Zr─O) cluster and glutamic acid are utilized to drive the self-assembly of flexible nanoribbons into pumpkin-like microspheres. The confined effect between water-flexible building blocks and crosslinked hydrogen networks of superstructures achieved a mismatch transformation of MOFs powders into homogeneous hydrogels.

Toxic effects of isofenphos-methyl on zebrafish embryonic development.

Isofenphos-methyl (IFP) is widely used as an organophosphorus for controlling underground insects and nematodes. However, excessive use of IFP may pose potential risks to the environment and humans, but little information is available on its sublethal toxicity to aquatic organisms. To address this knowledge gap, the current study exposed zebrafish embryos to 2, 4, and 8 mg/L IFP within 6-96 h past fertilization (hpf) and measured mortality, hatching, developmental abnormalities, oxidative stress, gene expressions, and locomotor activity.

On-site Simultaneous Determination of Neonicotinoids, Carbamates, and Phenyl Pyrazole Insecticides in Vegetables by QuEChERS Extraction on Nitrogen and Sulfur co-doped Carbon Dots and Portable Mass Spectrometry.

In food safety monitoring, on-site and simultaneous detection of a variety of insecticides with different concentrations in the same matrix is necessary. However, the task remains challenging. In this study, a novel nitrogen and sulfur co-doped carbon dot (N, S-CD) was synthesized and used as a QuEChERS clean-up reagent to reduce matrix interferences in the determination of insecticides in vegetables.

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.

Combining portable mass spectrometer with bamboo stir bar sorptive extraction for the on-site detection of malachite green, crystal violet and their metabolites in fishes.

In this work, a disposable and inexpensive bamboo stir bar containing an organic membrane was constructed to perform stir bar sorptive extraction (SBSE), followed by portable mass spectrometry to achieve on-site detection of four residual drugs (malachite green, crystal violet and their metabolites) in fishes. The entire method uses only microliter quantities of organic solvents, enabling environmentally friendly pretreatment. The portable mass spectrometer can simultaneously detect four target analytes in a sample in approximately ten seconds.

Thermal desorption bridged the gap between dielectric barrier discharge ionization and dried plasma spot samples for sensitive and rapid detection of fentanyl analogs in mass spectrometry.

The urgent threat of new psychoactive substances worldwide promotes rapid detection and identification demand for public security. Ambient ionization mass spectrometry (AIMS) has become mainstream among various detection techniques. Still, scant successful applications have been fulfilled toward dried blood spot (DBS) or plasma spot (DPS) as an easy-to-implement sampling format in AIMS.

[Detection of drugs in urine by ambient direct ionization mass spectrometry].

According to the Report of Drug Situation in China (2020), the growth rate of the number of drug abusers in China has decreased, but the number of drug abusers is still large. An efficient screening method is necessary for controlling drug abuse. As an important type of biological sample, urine is widely used for the rapid screening of drug addicts.

Multilayer Self-Assemblies for Fabricating Graphene-Supported Single-Atomic Metal via Microwave-Assisted Emulsion Micelle.

Inspired by molecular self-assemblies in nature, this article reports a versatile strategy for confined encapsulation of single-atomic metal into high-quality rGO nanosheets by the microwave-assisted emulsion micelle method. Multilayer self-assembly of organometallics-surfactants micelles into the interlayer of nanosheets can not only promote microwave exfoliation and reduction of GO but also precisely control loading and distribution of single-metal atoms. With this synthetic strategy, the simultaneous trinity of exfoliation, reduction, and composition are achieved for 1 min.

Hollow Cathode Discharge Ionization Mass Spectrometry: Detection, Quantification and Gas Phase Ion-Molecule Reactions of Explosives and Related Compounds.

Mass spectrometry (MS) has become an essential analytical method in every sector of science and technology. Because of its unique ability to provide direct molecular structure information on analytes, an extra method is rarely required. This review describes fabrication of a variable-pressure hollow cathode discharge (HCD) ion source for MS in detection, quantification and investigation of gas-phase ion molecule reactions of explosives and related compounds using air as a carrier gas.

Gas phase ion-molecule reactions of nitroaromatic explosive compounds studied by hollow cathode discharge ionization-mass spectrometry.

In this study, we have developed a variable pressure operating hollow cathode discharge (HCD) ion source to investigate the gas phase ion-molecule reactions of nitroaromatic explosive compounds. The developed HCD ion source coupled MS system has also been validated as an analytical method to analyze explosives at trace levels. The ion source was designed in such a way that the plasma can be generated alternatively at high pressure (~30 Torr), medium pressure (~5 Torr) and low pressure (~1 Torr) regions.

Simultaneous detection and quantification of explosives by a modified hollow cathode discharge ion source.

Detection of explosives at trace levels is crucial for security purposes because of increasing worldwide terrorist threats at public places. Previously, a hollow cathode discharge (HCD) ion source has been fabricated for detection of explosives. Recently, the HCD ion source has been modified for a dual pressures operating system and coupled to a linear ion trap MS to analyze explosives simultaneously.

[Rapid detection of sulfonamides by heat assisted desorption-dielectric barrier discharge ionization mass spectrometry].

Sulfanilamide is a common antibacterial drug that is used in clinical practice and in the industry. However, its abuse has emerged as a serious problem in the aquaculture industry, and more predominantly in the poultry industry, where it is administered for therapeutic purposes or as a growth promoter. In this study, a novel technical platform, heat-assisted desorption-dielectric barrier discharge ionization mass spectrometry (HAD-DBDI-MS), was used to detect sulfanilamide .

Single Cell Mass Spectrometry With a Robotic Micromanipulation System for Cell Metabolite Analysis.

Objective: The increasing demand for unraveling cellular heterogeneity has boosted single cell metabolomics studies. However, current analytical methods are usually labor-intensive and hampered by lack of accuracy and efficiency.

Methods: we developed a first-ever automated single cell mass spectrometry system (named SCMS) that facilitated the metabolic profiling of single cells.

Challenges and Strategies of Chemical Analysis of Drugs of Abuse and Explosives by Mass Spectrometry.

In analytical science, mass spectrometry (MS) is known as a "gold analytical tool" because of its unique character of providing the direct molecular structural information of the relevant analyte molecules. Therefore, MS technique has widely been used in all branches of chemistry along with in proteomics, metabolomics, genomics, lipidomics, environmental monitoring etc. Mass spectrometry-based methods are very much needed for fast and reliable detection and quantification of drugs of abuse and explosives in order to provide fingerprint information for criminal investigation as well as for public security and safety at public places, respectively.

Ultra-trace level detection of nonvolatile compounds studied by ultrasonic cutter blade coupled with dielectric barrier discharge ionization-mass spectrometry.

In analytical mass spectrometry, an efficient desorption is needed for nonvolatile compounds at ultra-trace level detection. In this paper, an ultrasonic cutter-assisted non-thermal desorption method for ultra-trace level detection of different types of nonvolatile compounds such as drugs of abuse, explosives, pharmaceuticals, spinosad, cholesterol, rhodamine B, glucose and amino acids has been described. The relevant compounds were deposited on the ultrasonic blade except pharmaceutical tablets that were used directly, and gently touched on perfluoroalkoxy (PFA) made substrate with oscillation frequency about 40 kHz in order to desorb the solid molecules.

Calculation of the overlap factor for scanning LiDAR based on the tridimensional ray-tracing method.

The overlap factor is used to evaluate the LiDAR light collection ability. Ranging LiDAR is mainly determined by the optical configuration. However, scanning LiDAR, equipped with a scanning mechanism to acquire a 3D coordinate points cloud for a specified target, is essential in considering the scanning effect at the same time.

An interface for online coupling capillary electrophoresis to dielectric barrier discharge ionization mass spectrometry.

The online combination of capillary electrophoresis (CE) with mass spectrometry (MS) has long been desired for the capability of direct and simultaneous separation and detection with high efficiency, accuracy, and throughput. In this work, a novel CE-MS interface was developed, using dielectric barrier discharge ionization (DBDI). The interface employed a spray tip with a coaxial three-layer structure, into which the CE sample solution, the sheath liquid, and the nebulizing gas were introduced.

A dielectric barrier discharge ionization based interface for online coupling surface plasmon resonance with mass spectrometry.

The online combination of surface plasmon resonance (SPR) with mass spectrometry (MS) could be beneficial for accurately acquiring molecular interaction data simultaneously with their structural information at high throughputs. In this work, a novel SPR-MS interface was developed using a dielectric barrier discharge ionization (DBDI) source. The DBDI source was placed in front of the MS inlet, generating an ionization plasma jet.