Rapid Screening and Quantification of PFAS Enabled by SPME-DART-MS.

Per- and polyfluoroalkyl substances (PFAS), an emerging class of toxic anthropogenic chemicals persistent in the environment, are currently regulated at the low part-per-trillion level worldwide in drinking water. Quantification and screening of these compounds currently rely primarily on liquid chromatography hyphenated to mass spectrometry (LC-MS). The growing need for quicker and more robust analysis in routine monitoring has been, in many ways, spearheaded by the advent of direct ambient mass spectrometry (AMS) technologies.

COVID-19, Personal Protective Equipment, and Human Performance.

Clinicians who care for patients infected with coronavirus disease 2019 (COVID-19) must wear a full suite of personal protective equipment, including an N95 mask or powered air purifying respirator, eye protection, a fluid-impermeable gown, and gloves. This combination of personal protective equipment may cause increased work of breathing, reduced field of vision, muffled speech, difficulty hearing, and heat stress. These effects are not caused by individual weakness; they are normal and expected reactions that any person will have when exposed to an unusual environment.

Solvent-free, Noncontact Electrostatic Sampling for Rapid Analysis with Mass Spectrometry: Application to Drugs and Explosives.

A hand-held Van de Graaf generator is used to apply a high voltage, negligible current electrostatic potential to a wire mesh positioned in close proximity to a particle-laden surface in order to collect those particles for analysis. The electrostatic field effects transfer particles to the mesh without a requirement for mechanical contact between mesh and surface. Analysis of chemicals present in the sampled particles is completed by thermal desorption electrospray ionization.

Rapid fingerprinting of source and environmental microplastics using direct analysis in real time-high resolution mass spectrometry.

Microplastics are ubiquitous in the aquatic and terrestrial environment. To prevent further contamination, methods to determine their sources are needed. Techniques to quantify and characterize microplastics in the environment are still evolving for polymers and the additives and leachable substances embedded therein, which constitute the "chemical fingerprint" of an environmental microplastic.

Effect of reducing sample volume on the detection of drugs in urine by transmission mode direct analysis in real time mass spectrometry.

Rationale: Matrix interference attributed to urea and other nitrogenous substances in unprocessed urine is significant. In this study desorption ionization of sub-microliter volume samples is performed in an effort to improve the detection of drugs in unprocessed urine using transmission mode-direct analysis in real time mass spectrometry (TM-DART-MS).

Methods: Urine samples were spiked with analytical standards of two drugs of abuse, codeine and methadone.

High-Throughput Extraction and Detection of Drugs in Urine: Parallel Sampling with Solid-Phase Microextraction (SPME) Fibers Coupled with Direct Analysis in Real Time-Mass Spectrometry (DART-MS) Detection.

Determination of drugs of abuse in urine is routinely accomplished by utilizing solid-phase extraction to isolate the drugs and gas chromatography/mass spectrometry (GC/MS) for their detection. Although robotic systems are employed, throughput is limited by the extraction process and GC chromatographic separation.A method that utilizes an array of 12 solid-phase microextraction (SPME) fibers for simultaneous isolation of drugs of abuse from urine is provided as a means to increase productivity.

A method for rapid sampling and characterization of smokeless powder using sorbent-coated wire mesh and direct analysis in real time - mass spectrometry (DART-MS).

Improvised explosive devices (IEDs) are often used by terrorists and criminals to create public panic and destruction, necessitating rapid investigative information. However, backlogs in many forensic laboratories resulting in part from time-consuming GC-MS and LC-MS techniques prevent prompt analytical information. Direct analysis in real time - mass spectrometry (DART-MS) is a promising analytical technique that can address this challenge in the forensic science community by permitting rapid trace analysis of energetic materials.

Direct analysis in real time-Mass spectrometry (DART-MS) in forensic and security applications.

Over the last decade, direct analysis in real time (DART) has emerged as a viable method for fast, easy, and reliable "ambient ionization" for forensic analysis. The ability of DART to generate ions from chemicals that might be present at the scene of a criminal activity, whether they are in the gas, liquid, or solid phase, with limited sample preparation has made the technology a useful analytical tool in numerous forensic applications. This review paper summarizes many of those applications, ranging from the analysis of trace evidence to security applications, with a focus on providing the forensic scientist with a resource for developing their own applications.

Detection of "bath salt" synthetic cathinones and metabolites in urine via DART-MS and solid phase microextraction.

A rapid and sensitive method, direct analysis in real time mass spectrometry (DART-MS) was applied to the characterization and semiquantitative analysis of synthetic cathinones and their metabolites in urine. DART-MS was capable of detecting three different cathinones and three metabolites down to sub-clinical levels directly without any sample preparations. The process produced a spectrum within seconds because no extraction or derivatization was required for analysis and the high mass accuracy of the instrumentation allowed analysis without the need for lengthy chromatographic separations.

Evaluating a direct swabbing method for screening pesticides on fruit and vegetable surfaces using Direct Analysis in Real Time (DART) coupled to an Exactive benchtop orbitrap mass spectrometer.

Rapid screening of pesticides present on the surfaces of fruits and vegetables has been facilitated by using a Direct Analysis in Real Time (DART(®)) open air surface desorption ionization source coupled to an Exactive(®) high-resolution accurate mass benchtop orbitrap mass spectrometer. The use of cotton and polyester cleaning swabs to collect and retain pesticides for subsequent open air desorption ionization is demonstrated by sampling the surface of various produce to which solutions of pesticides have been applied at levels 10 and 100 times below the tolerance levels established by the United States Environmental Protection Agency (US EPA). Samples analyzed include cherry tomatoes, oranges, peaches and carrots each chosen for their surface characteristics which include: smooth, pitted, fuzzy, and rough respectively.

Increasing the rate of sample vaporization in an open air desorption ionization source by using a heated metal screen as a sample holder.

Rapid vaporization of sample into the ionizing gas exiting a direct analysis in real time (DART®) source has been enabled by directing a high electrical current through a metal wire screen to which sample has been applied. This direct heating of the screen enables rapid vaporization of sample as the wire temperature rises from room temperature to greater than 400°C in less than 20 s. Positioning the screen between the DART source and atmospheric pressure inlet of the mass spectrometer ensures that the ionizing gas is in close proximity to the sample molecules, resulting in efficient ionization while significantly reducing the time required for mass spectrometric analysis.

Direct analysis in real time coupled with dried spot sampling for bioanalysis in a drug-discovery setting.

Background: Conventional mouse or rat pharmacokinetic/toxicokinetic (PK/TK) studies frequently require sacrifice or use of multiple animals for a full time-course in order to obtain adequate blood volume. Currently accepted LC-MS/MS analyses require tedious sample preparation and large blood volume, therefore, a bioanalytical method with a simpler blood-sampling procedure using fewer animals, lower sample volume and no additional sample preparation is desirable.

Results: We have developed a method that combines the direct analysis in real time (DART) open-air ambient ionization source and MS/MS to directly analyze dried blood spots (DBS) on glass from low volume whole blood samples without additional sample preparation or manipulation of the spots.

Principal component directed partial least squares analysis for combining nuclear magnetic resonance and mass spectrometry data in metabolomics: application to the detection of breast cancer.

Nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) are the two most commonly used analytical tools in metabolomics, and their complementary nature makes the combination particularly attractive. A combined analytical approach can improve the potential for providing reliable methods to detect metabolic profile alterations in biofluids or tissues caused by disease, toxicity, etc. In this paper, (1)H NMR spectroscopy and direct analysis in real time (DART)-MS were used for the metabolomics analysis of serum samples from breast cancer patients and healthy controls.

Bioanalysis without sample cleanup or chromatography: the evaluation and initial implementation of direct analysis in real time ionization mass spectrometry for the quantification of drugs in biological matrixes.

Two key bottlenecks in pharmaceutical bioanalysis are sample cleanup and chromatographic separations. Although multiple approaches have been developed in the past decade to either shorten or multiplex these steps, they remain the rate limiting steps as ADME (Absorption, Distribution, Metabolism, and Excretion) property screening is being routinely incorporated into the drug discovery process. In this work, a novel system incorporating an automated Direct Analysis in Real Time (DART) ionization source coupled with a triple-quadrupole mass spectrometer has been developed and evaluated for quantitative bioanalysis.

Direct analysis in real time for reaction monitoring in drug discovery.

Direct analysis in real time (DART) is a novel ionization technique that provides for the rapid ionization of small molecules under ambient conditions. In this study, several commercially available drugs as well as actual compounds from drug discovery research were examined by LC/UV/ESI-MS and DART interfaced to a quadrupole mass spectrometer. For most compounds, the molecular ions observed by ESI-MS were observed by DART/MS.

Atmospheric pressure laser desorption/ionization on porous silicon.

A recently developed commercial atmospheric pressure matrix-assisted laser desorption/ionization (AP-MALDI) source (MassTech, Inc.) was modified to adopt commercially available DIOS plates (Mass Consortium Corp.) for the studies of laser desorption from the surface of porous silicon under atmospheric pressure conditions.