Here we describe a state-of-the-art, integrated, multi-instrument automated system designed to execute methods involved in mass spectrometry characterization of biotherapeutics. The system includes liquid and microplate handling robotics and utilities, integrated LC-MS, along with data analysis software, to perform sample purification, preparation, and analysis as a seamless integrated unit. The automated process begins with tip-based purification of target proteins from expression cell-line supernatants, which is initiated once the samples are loaded onto the automated system and the metadata are retrieved from our corporate data aggregation system. Subsequently, the purified protein samples are prepared for MS, including deglycosylation and reduction steps for intact and reduced mass analysis, and proteolytic digestions, desalting, and buffer exchange via centrifugation for peptide map analysis. The prepared samples are then loaded into the LC-MS instrumentation for data acquisition. The acquired raw data are initially stored on a local area network storage system that is monitored by watcher scripts that then upload the raw MS data to a network of cloud-based servers. The raw MS data are processed with the appropriately configured analysis workflows such as database search for peptide mapping or charge deconvolution for undigested proteins. The results are verified and formatted for expert curation directly in the cloud. Finally, the curated results are appended to sample metadata in the corporate data aggregation system to accompany the biotherapeutic cell lines in subsequent processes.

Per- and polyfluoroalkyl substances (PFAS) are a class of manufactured chemicals that have been extensively utilized worldwide. We hypothesize that the presence, uptake, and accumulation of PFAS in aquatic vegetation (AV) is dependent upon several factors, such as the physiochemical properties of PFAS and proximity to potential sources. In this study, AV was collected from eight locations in Florida to investigate the PFAS presence, accumulation, and spatiotemporal distribution. PFAS were detected in AV at all sampling locations, with a range from 0.18 to 55 ng/g sum (∑)PFAS. Individual PFAS and their concentrations varied by sampling location, time, and AV species. A total of 12 PFAS were identified, with the greatest concentrations measured in macroalgae. The average bioconcentration factor (BCF) among all samples was 1225, indicating high PFAS accumulation in AV from surface water. The highest concentrations, across all AV types, were recorded in the Indian River Lagoon (IRL), a location with a history of elevated PFAS burdens. The present study represents the first investigation of PFAS in naturally existing estuarine AV, filling an important gap on PFAS partitioning within the environment, as well as providing insights into exposure pathways for aquatic herbivores. Examining the presence, fate, and transport of these persistent chemicals in Florida’s waterways is critical for understanding their effect on environmental, wildlife, and human health.

Since the beginning of the industrial revolution, humans have burned enormous quantities of coal, oil, and natural gas, rivaling nature’s elemental cycles of C, N, and S. The result has been a disruption in a steady state of CO2 and other greenhouse gases in the atmosphere, a warming of the planet, and changes in master variables (temperature, pH, and pε) of the sea affecting critical physical, chemical, and biological reactions. Humans have also produced copious quantities of N and P fertilizers producing widespread coastal hypoxia and low dissolved oxygen conditions, which now threaten even the open ocean. Consequently, our massive alteration of state variables diminishes coral reefs, fisheries, and marine ecosystems, which are the foundation of life on Earth. We point to a myriad of actions and alternatives which will help to stem the tide of climate change and its effects on the sea while, at the same time, creating a more sustainable future for humans and ecosystems alike.

Mass spectrometry analysis can be performed by introducing samples directly to mass spectrometry, allowing the increase of the analysis throughput; however, some disadvantages of direct-to-mass spectrometry analysis include susceptibility to matrix effects and risk of instrument contamination from inadequate sample preparation. Solid-phase microextraction is one of the most suitable sample preparation methods for direct-to-mass spectrometry analysis, as it offers matrix-compatible coatings which ensure analyte enrichment with minimal or no interference from matrix. One of the ways solid-phase microextraction can be coupled directly to mass spectrometry is via a microfluidic open interface. This manuscript reports improvements made to the initial microfluidic open interface design, where the system components have been simplified to mostly commercially available materials. In addition, the analysis of samples has been automated by implementing software that fully controls the analysis workflow, where the washing procedure is optimized to completely reduce the carryover. Herein, the extraction and desorption time profiles from thin and thick SPME devices was studied where the overall workflow consisted of high-throughput sample preparation of 1.3 min per 96 samples and <1 min per sample instrumental analysis.

Developing advanced onsite wastewater treatment systems (OWTS) requires accurate and consistent water quality monitoring to evaluate treatment efficiency and ensure regulatory compliance. However, off-line parameters such as chemical oxygen demand (COD), total suspended solids (TSS), and Escherichia coli (E. coli) require sample collection and time-consuming laboratory analyses that do not provide real-time information of system performance or component failure. While real-time COD analyzers have emerged in recent years, they are not economically viable for onsite systems due to cost and chemical consumables. This study aimed to design and implement a real-time remote monitoring system for OWTS by developing several multi-input and single-output soft sensors. The soft sensor integrates data that can be obtained from well-established in-line sensors to accurately predict key water quality parameters, including COD, TSS, and E. coli concentrations. The temporal and spatial water quality data of an existing field-tested OWTS operated for almost two years (n = 56 data points) were used to evaluate the prediction performance of four machine learning algorithms. These algorithms, namely, partial least square regression (PLS), support vector regression (SVR), cubist regression (CUB), and quantile regression neural network (QRNN), were chosen as candidate algorithms for their prior application and effectiveness in wastewater treatment predictions. Water quality parameters that can be measured in-line, including turbidity, color, pH, NH4+, NO3–, and electrical conductivity, were selected as model inputs for predicting COD, TSS, and E. coli. The results revealed that the trained SVR model provided a statistically significant prediction for COD with a mean absolute percentage error (MAPE) of 14.5% and R2 of 0.96. The CUB model provided the optimal predictive performance for TSS, with a MAPE of 24.8% and R2 of 0.99. None of the models were able to achieve optimal prediction results for E. coli; however, the CUB model performed the best with a MAPE of 71.4% and R2 of 0.22. Given the large fluctuation in the concentrations of COD, TSS, and E. coli within the OWTS wastewater dataset, the proposed soft sensor models adequately predicted COD and TSS, while E. coli prediction was comparatively less accurate and requires further improvement. These results indicate that although water quality datasets for the OWTS are relatively small, machine learning-based soft sensors can provide useful predictive estimates of off-line parameters and provide real-time monitoring capabilities that can be used to make adjustments to OWTS operations.

The American Society for Mass Spectrometry was founded in 1969. (1) Over the years, the Society has experienced rapid growth and is composed of >7500 members, representing a diverse group of individuals from varied industry, government, and academic settings. The stated goal of ASMS is “to promote and disseminate knowledge of mass spectrometry and allied topics”. (1) One component of that mission is the publication of the Journal of the American Society for Mass Spectrometry (JASMS). As the publication industry is adapting to rapidly evolving policies, JASMS seeks to ensure it fully represents the diverse interests of all subdisciplines of mass spectrometry while aligning to modern publication standards. We hope this editorial helps to inspire and provide you with an opportunity to help shape JASMS to suit the needs of each ASMS member. As a 501(c)(3) charitable organization duly formed in the United States, ASMS is bound by laws that dictate aspects of the Society, including membership and governing structure. ASMS is led by a nine-member Board of Directors who have been elected by the members of the Society. As the Board of Directors provides governance through directing Society functions and ensuring financial security, it is critical to the success of ASMS. To manage specific aspects of the Society, the Board relies on committees. The board structure consists of the offices of President, Vice President for Programs, Vice President for Arrangements, Treasurer, Secretary, and Past President. In addition to these individuals, three Members-at-Large direct the efforts of the Membership, Education, and Publication committees. The members of the committees serve two-year terms and are selected from the ASMS membership as recommended by the committee members and approved by the Board of Directors. Here, we introduce you to the current members of the Publications Committee. Stephen Valentine, ASMS Member-at-Large for Publications, is an Associate Professor of Chemistry at West Virginia University where he develops new MS instrumentation and techniques for ‘omics analyses. Vanessa Phelan is an Assistant Professor of Pharmaceutical Science at University of Colorado Anschutz Medical Campus, where she develops new methods to investigate microbial metabolomics. Mowei Zhou (PNNL) is a national lab staff scientist who specializes in native top-down MS. Stefani Thomas (University of Minnesota Medical School) is an Assistant Professor of Laboratory Medicine and Pathology who applies mass spectrometry-based proteomics methods to elucidate the biology of ovarian cancer; she is also a Clinical Chemist serving as the Associate Medical Director of the M Health Fairview West Bank Laboratory. Joe Cannon is a Scientific Associate Director of Biotransformation at Bristol Myers Squibb. The Publications Committee is chaired by the ASMS Member-at-Large for Publications. The committee performs several main functions, namely: (1) review content and assist with testing of online conference proceedings; (2) act as liaison between ASMS and JASMS; (3) develop educational publications (with the Education Committee) such as brochures and posters on specific topics; (4) contribute content to the Society Web site; and (5) meet at the annual conference and prepare a report for the ASMS Board of Directors. While all of this work is important, for the remainder of this informational editorial, we focus on our efforts to interface with the board and the JASMS team. In performing its liaison duties mentioned above, the Publications Committee meets regularly with Professor Vicki Wysocki, the current Editor-in-Chief (EIC) of JASMS. This interaction provides an effective channel for bidirectional information flow between the ASMS Board of Directors and the EIC. In these meetings, specific concerns are discussed such as suggested actions to recompose the Editorial Board. The Publications Committee also holds discussions regarding the performance of JASMS. One topic of consideration is how to increase the impact factor of the journal while not sacrificing its commitment to represent all relevant MS topics. Still other discussions are concerned with plans to increase the visibility of JASMS. As part of these efforts, the committee has worked with outstanding JASMS Twitter account managers. Past managers include graduate students Cameron Worthington and Tiffany Cummings (UNC Chapel Hill); the current managers are graduate students Liam Dugan (Carnegie Mellon University) and Kimberly Fabijanczuk (Purdue University). These individuals have volunteered numerous hours to provide increased visibility (with a dash of fun) for JASMS. Because board governance is only as good as the support received from the members of the Society, in closing we issue a call to arms. We ask, “what can you do to help us in our service?” First, it is important to become/maintain membership in ASMS. The Society benefits from all perspectives and the work performed by each of the members. Second, get to know the individual members of the committee, which enables you to make appropriate suggestions to improve JASMS. Third, make suggestions for new committee members as well as the Member-at-Large position. The suggestions for new committee members can be provided to the current committee members; the suggestion for the latter position can be made to members of the ASMS Board of Directors. While making such suggestions, please note the commitment by the society to ensure that the members of the board and each standing committee reflect its diverse membership. Finally, vote! We recently held elections to replace outgoing Board of Directors members, including the Member-at-Large for Publications. We are excited to welcome Kelly Hines (University of Georgia) as the newly elected Member-at-Large for Publications. We know that the work of this committee is in good hands. We also wish to thank you all for all your efforts and your support. Sincerely, This article references 1 other publications. This article has not yet been cited by other publications. This article references 1 other publications.

The mass distribution of ions influences separations in ion mobility spectrometry-mass spectrometry (IMS-MS). Herein, we introduce a method to induce mass distribution shifts for various analytes using hydrogen-deuterium exchange (HDX) immediately prior to ionization using a dual syringe approach. By replacing labile hydrogens on analytes with deuteriums, we were able to differentiate isomers using separations of isotopologues. For each analyte studied, every possible level of deuteration (from undeuterated to fully deuterated) was generated and then separated using cyclic ion mobility spectrometry-mass spectrometry (cIMS-MS). The information gained from such separations (relative arrival times; tRel. values) was found to be orthogonal to conventional IMS-MS separations. Additionally, the observed shifts were linearly additive with increasing deuteration, suggesting that this methodology could be extended to analytes with a larger number of labile hydrogens. For one isomer pair, as few as two deuteriums were able to produce a large enough mass distribution shift to differentiate isomers. In another experiment, we found that the mass distribution shift was large enough to overcome the reduced mass contribution, resulting in a “flipped” arrival time where the heavier deuterated isotopologue arrived before the lighter one. In this work, we present a proof-of-concept demonstration that mass-distribution-based shifts, tRel. values, could potentially act as an added dimension to characterize molecules in IMS-MS. We anticipate, along with future work in this area, that mass-distribution-based shifts could enable the identification of unknown molecules through a database-driven approach in an analogous fashion to collision cross section (CCS) measurements.

A mechanism of unusual tandem (MS/MS) fragmentation of protonated species of N-(triphenyl-λ5-phosphanylidene) derivatives, [M + H]+ to generate triphenylphosphine oxide (TPPO) within the mass spectrometer has been investigated and reported. Collision-induced dissociation of these molecules resulted in the generation of TPPO as a signature fragment. This fragment suggested the presence of a P–O bond in the structure which was contrary to the structure of the compound identified by nuclear magnetic resonance spectrometry (NMR) and single-crystal X-ray diffractometry (SXRD) techniques with a P═N bond rather than a P–O bond. In order to confirm the generation of the TPPO fragment within the mass spectrometer, 14 different N-(triphenyl-λ5-phosphanylidene) derivatives containing amide, 18O-labeled amide, thiamide, and nonacyl phosphazene derivatives were synthesized and their MS/MS behavior was studied by liquid chromatography–high-resolution mass spectrometry. Fragmentation of these amide derivatives generated TPPO/TPPS or their 18O-labeled analogues as the major fragment in almost all cases under similar MS conditions. Based on the outcome of these experiments, a plausible mechanism for such fragmentation, involving the intramolecular shifting of oxygen from carbon to phosphorus, has been proposed. DFT calculations for the protonated species at B3LYP-D3/6-31+G(d,p) further supported the proposed mechanism involving a four-membered ring, P–O–C–N, as the transition state. Details of this work are presented here.

The aggregation of islet amyloid polypeptide (IAPP) is associated with β-cell dysfunction in type 2 diabetes (T2D) in humans. One possible mechanism of toxicity is the interaction of IAPP oligomers with lipid membranes to disrupt the bilayer integrity and/or homeostasis of the cell. Amino acid sequence variations of IAPPs between species can greatly decrease their propensity for aggregation. For example, human IAPP is toxic to β-cells, but rat and pig IAPP are not. However, it is not clear how these differences affect membrane association. Using native mass spectrometry with lipid nanodiscs, we explored the differences in the association of human, rat, and pig IAPP with lipid bilayers. We discovered that human and rat IAPP bound nanodiscs with anionic dipalmitoyl-phosphatidylglycerol (DPPG) lipids, but pig IAPP did not. Furthermore, human and rat IAPP interacted differently with the membrane. Human IAPP show potential tetramer complexes, but rat IAPP associated with the membrane sequentially. Thus, overall IAPP–bilayer interactions are not necessarily related to disease, but small differences in oligomeric behavior at the membrane may instead play a role.

Glyphosate (GLY), a synthetic, nonselective systemic herbicide that is particularly effective against perennial weeds, is the most used weedkiller in the world. There are growing concerns over GLY accumulation in the environment and the attendant human health-associated risks, and despite increased attention in the media, GLY and its breakdown product aminomethylphosphonic acid (AMPA) remain elusive to many analytical strategies. Chemical derivatization coupled with high-performance liquid chromatography-mass spectrometry (HPLC-MS) addresses the challenge of quantifying low levels of GLY and AMPA in complex samples. Here we demonstrate the use of in situ trimethylation enhancement using diazomethane (iTrEnDi) to derivatize GLY and AMPA into permethylated products ([GLYTr]+ and [AMPATr]+, respectively) prior to analysis via HPLC-MS. iTrEnDi produced quantitative yields and resulted in a 12–340-fold increases in HPLC-MS-based sensitivity for [GLYTr]+ and [AMPATr]+, respectively, compared with underivatized counterparts. The limits of detection of derivatized compounds were found to be 0.99 ng/L for [GLYTr]+ and 1.30 ng/L for [AMPATr]+, demonstrating significant sensitivity improvements compared to previously established derivatization techniques. iTrEnDi is compatible with the direct derivatization of Roundup formulations. Finally, as proof of principle, a simple aqueous extraction followed by iTrEnDi enabled the detection of [GLYTr]+ and [AMPATr]+ on the exterior of field-grown soybeans that were sprayed with Roundup. Overall, iTrEnDi ameliorates issues relating to low proton affinity and chromatographic retention, boosting HPLC-MS-based sensitivity and enabling the elucidation of elusive analytes such as GLY and AMPA within agricultural systems.

Common sampling methods for mass spectrometry such as sectioning are undesirably damaging to cultural heritage objects. A liquid microjunction sampling technique is developed that uses minimal solvent volume for analysis. Painted illustrations on a 17th century parchment manuscript from Spain were analyzed to identify the organic red pigment throughout its pages. By extracting with 0.1 μL solvent, the pigment was supplied for direct infusion electrospray MS, and the resulting disruption to the object surface was practically invisible to the naked eye.

The analysis of large molecules is challenging, as they often have salts and adducts retained through the electrospray process, which increase the observed mass and compromise the achievable mass resolution. Mild collisional activation has been shown to be very effective for the removal of adducts and increases both measurement accuracy and mass resolution of large (>100 kDa) protein complexes. Collisionally activated protein ions are more completely desolvated due to the increased number of collisions when trapped following activation. A short square quadrupole maintained at 300 mTorr by a mechanical pump was added between the ion funnel and transmission quadrupole. This configuration and operation effectively removed adducts from the 800 kDa tetradecamer GroEL as well as fragmented smaller protein complexes like C-reactive protein. Due to the gas high pressure, ions of low size-to-charge ratio, such as those in charge reducing buffers, had low ejection efficiency. We show that segmenting the quadrupole rods greatly improves signal intensity for charge reduced GroEL D398A mutant compared to nonsegmented rods when operating at high pressure.

Between 2003 and 2017, four reports were published that demonstrated the intrinsic ability of the native iron-containing proteins cytochrome c and ferritin to undergo radical-based backbone fragmentation in the gas phase without the introduction of exogenous electrons. For cytochrome c in particular, this effect has so far only been reported to occur in the ion source, preventing the in-depth study of reactions occurring after gas-phase isolation of specific precursors. Here, we report the first observation of this intrinsic native electron capture dissociation behavior after quadrupole isolation of specific charge states of the cytochrome c dimer and trimer, providing direct experimental support for key aspects of the mechanism proposed 20 years ago. Furthermore, we provide evidence that, in contrast to some earlier proposals, these oligomeric states are formed in bulk solution rather than during the electrospray ionization process and that the observed fragmentation site preferences can be rationalized through the structure and interactions within these native oligomers rather than the monomer. We also show that the observed fragmentation pattern─and indeed, whether or not fragmentation occurs─is highly sensitive to the provenance and history of the protein samples, to the extent that samples can show distinct fragmentation behavior despite behaving identically in ion mobility experiments. This rather underexplored method therefore represents an exquisitely sensitive conformational probe and will hopefully receive more attention from the biomolecular mass spectrometry community in the future.

As one of the most critical steps in process development for protein therapeutics, clone selection and cell culture optimization require a large number of samples to be screened for high titer and desirable molecular profiles. Typical analytical techniques, such as chromatographic approaches, often take minutes per sample which are inefficient for large-scale screenings. Droplet microfluidics coupled to mass spectrometry (MS) represents an attractive approach due to its low volume requirements, high-throughput capabilities, label-free nature, and ability to handle complex mixtures. In this work, we coupled a modified protein cleanup protocol with a droplet-MS workflow for mAb titer screening to guide clone selection. With this droplet approach we achieved a throughput of 0.04 samples/s with an LoD of 0.15 mg/mL and an LoQ of 0.45 mg/mL. To test its performance in a real-world setting, this workflow was applied to a 35-clone screen, where the top 20% producing clones were identified. In addition, we coupled our sample cleanup protocol to a high-resolution MS and compared the glycan profiles of the high titer clones. This work demonstrates that droplet-MS provides a rapid way of clone screening and cell culture optimization based on titer and molecular structure of the expressed proteins. Future work is aimed at increasing the throughput and automation of this droplet-MS technique.

To capture the structure of assembled hemagglutinin (HA) nanoparticles at single-particle resolution, HA-specific antigen binding fragments (Fabs) were labeled by fluorescent (FLR) dyes as probes to highlight the HA trimers displayed on the assembled tetravalent HA nanoparticles for a qualitative localization microscopic study. The FLR dyes were conjugated to the Fabs through N-hydroxysuccinimide (NHS) ester mediated amine coupling chemistry. The labeling profile, including labeling ratio, distribution, and site-specific labeling occupancy, can affect the imaging results and introduce inconsistency. To evaluate the labeling profile so as to evaluate the labeling efficiency, a combination of intact mass measurement by MALDI-MS and peptide mapping through LC-MS/MS was implemented. At the intact molecular level, the labeling ratio and distribution were determined. Through peptide mapping, the labeled residues were identified and the corresponding site-specific labeling occupancy was measured. A systematic comparative investigation of four different FLR-labeled 1H01-Fabs (generated from H1 strain HA specific mAb 1H01) allowed accurate profiling of the labeling pattern. The data indicate that the labeling was site-specific and semiquantitative. This warrants the consistency of single-particle fluorescent imaging experiments and allows a further imaging characterization of the single nanoparticles.

The diversity of ubiquitin modifications calls for methods to better characterize ubiquitin chain linkage, length, and morphology. Here, we use multiple linear regression analysis coupled with ion mobility mass spectrometry (IM-MS) to quantify the relative abundance of different ubiquitin dimer isomers. We demonstrate the utility and robustness of this approach by quantifying the relative abundance of different ubiquitin dimers in complex mixtures and comparing the results to the standard, bottom-up ubiquitin AQUA method. Our results provide a foundation for using multiple linear regression analysis and IM-MS to characterize more complex ubiquitin chain architectures.

Global environmental change is real in the Anthropocene. Global warming is happening now, caused by anthropogenic activities with the emission of greenhouse gases. The latest reading of “the Keeling curve” has topped 424 ppm of carbon dioxide, which represents the highest record in continuous measurements of CO2 at Mauna Loa Observatory in Hawaii since 1960. (1) Climate change has become more prominent and more evident that we experience it even in our daily life. Weather events have intensified with record-shattering climate extremes. (2) This winter, we experienced record-breaking rainfall and snowfall associated with the atmospheric river in the West of the United States, while facing off against heat in the East of the United States. Biomass burning and wildfires have increased with higher frequency, longer durations, and longer seasons. (3) Hurricanes have become more frequent and stronger, causing flooding in various places around the globe. These extreme events in a warming planet disrupt and negatively impact our society, restructuring our lifestyles in a myriad of ways, e.g., in sports: a recent study showed that global warming causes a reduction in ballpark air density, promoting more home runs in Major League Baseball games (4) (bad news for pitchers!). Even though they are managed separately, climate change is coupled with air quality. There are cobenefits of climate regulations on improving air quality, but so far there is a lack of tools to rigorously evaluate the implications of addressing these challenges simultaneously. Sebastian D. Eastham and colleagues developed a computationally efficient approach to quantify how combined climate and air quality interventions affect air quality outcomes. Their approach captures spatial heterogeneity and complex atmospheric chemistry involving ozone, nitrogen oxides, volatile organic compounds, ammonia, and particulate matter, enabling rapid assessments modeling air quality–climate interactions. They demonstrate that air quality impact of climate policy depends on precursor emission stringency. In addition to greenhouse gases, particulate matter containing chromophores, so-called brown carbon, affects the climate by posing positive radiative forcing and serving as cloud condensation nuclei (CCN). The chemical composition and climate-relevant properties of brown carbon are highly dynamic, as they evolve upon chemical transformation in the atmosphere. Borduas-Dedekind and colleagues tackle this problem by irradiating lab-generated and field-collected brown carbon samples. They specifically focused on investigating photomineralization, a photodegradation process that fragments organic molecules to CO and CO2. They found that the rates of photomineralization were fastest for lab-generated samples and slowest for ambient brown carbon samples. Despite photobleaching and composition changes in the brown carbon, its CCN abilities did not change substantially. There are three more exciting publications in this issue. Kanel, Nadagouda, and colleagues review the groundwater contamination of arsenic (As), which can pose serious health risks. They summarize the origin, geochemistry, occurrence, mobilization, and microbial interaction of natural and anthropogenic-As, and common remediation technologies for As removal from groundwater. Pickering, Julian, and colleagues systematically reviewed the prevalence and concentrations of fecal indicator microorganisms and enteric pathogens on hands, and highlighted the importance of standardizing hand sampling methods. Finally, Guest and colleagues introduced an open-source multicriteria decision analysis package that enables users to transparently compare sanitation and resource recovery alternatives and characterize the opportunity space for early stage technologies. We sincerely thank these authors and reviewers for their contributions to these publications. We hope you enjoy reading these interesting articles in our latest issue. This article references 4 other publications. This article has not yet been cited by other publications. This article references 4 other publications.

N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD)-quinone (6PPD-Q), a transformation byproduct of 6PPD used in tires as an antiozonant and antioxidant, was recently discovered as the chemical primarily responsible for the acute lethal toxicity of urban storm runoff to coho salmon. The asphalt concrete (AC) surface layer is the primary medium to contact 6PPD-Q immediately upon its release from tires, and the addition of recycled tire rubber (RTR) to the asphalt binder and mixture is a widely accepted practice in asphalt production. Therefore, it is urgent to understand the fate of 6PPD-Q at the asphalt concrete surface layer–water interface. This study analyzed the sorption and desorption of 6PPD-Q by compacted and crushed loose (loose particles, ∼5 mm) rubberized asphalt mixtures and their mobilization from compacted asphalt mixtures during simulated rainfall events. It should be noted that the crushed loose asphalt mixtures demonstrated the physicochemical properties of the asphalt materials, while the compacted asphalt mixtures represent in-service AC layers. Sorption of 6PPD-Q by crushed loose and compacted asphalt mixtures reached equilibrium within 12 days, with a sorption coefficient of 151.57–257.51 L/kg for compacted asphalt mixtures. Within 12 days, desorption of 6PPD-Q from crushed loose and compacted rubberized asphalt mixtures (20 g particles/L) to the double deionized (DDI) water and synthetic stormwater was 0.01–0.09 and 0.025–0.05 μg/L, respectively. Through the rainfall simulation experiments, 0.0015–0.0049 μg/L 6PPD-Q was detected in the runoff water, much lower than the lethal concentration (LC50) of 6PPD-Q of 0.095 μg/L and 308.67 μg/L for coho salmon and zebrafish larvae. Our results indicate that, while the release of 6PPD-Q from compacted rubberized asphalt mixtures is minor, the mixtures can serve as sorbents for tire-derived 6PPD-Q and retain this emerging contaminant.

Glycosylation is an important protein post-translational modification that plays a pivotal role in the bioactivity of therapeutic proteins and in the infectivity of viral proteins. Liquid chromatography with tandem mass spectrometry readily identifies protein glycans with site specificity. However, the overnight incubation used in conventional in-solution proteolysis leads to high turnaround times for glycosylation analysis, particularly when sequential in-solution digestions are needed for site-specific glycan identification. Using bovine fetuin as a model glycoprotein, this work first shows that in-membrane digestion in ∼3 min yields similar glycan identification and quantitation when compared to overnight in-solution digestion. Protease-containing membranes in a spin column enable digestion of therapeutic proteins (trastuzumab and erythropoietin) and a viral protein (SARS-CoV-2 receptor binding domain) in ∼30 s. Glycan identification is similar after in-solution and in-membrane digestion, and limited in-membrane digestion enhances the identification of high-mannose glycans in trastuzumab. Finally, stacked membranes containing trypsin and chymotrypsin allow fast sequential proteolytic digestion to site-specifically identify the glycans of SARS-CoV-2 receptor binding domain. One can easily assemble the protease-containing membranes in commercial spin columns, and spinning multiple columns simultaneously will facilitate parallel analyses.

Products and starting materials containing volatile organic compounds (VOCs) can easily be found in a variety of businesses, making them a common source of occupational exposure. To prevent negative impacts on employee health, field industrial hygienists must conduct regular sampling to ensure exposures remain below the regulatory limits set by governmental and professional associations. As such, the need for sensitive and reliable exposure assessment techniques becomes evident. Over the preceding decade, the industrial hygiene research group at the University of Alabama at Birmingham (UAB) has been working on the development of an emerging, preanalytical technique known as photothermal desorption (PTD) to improve upon the analytical sensitivity of currently employed methods. PTD’s novel design uses pulses of high-energy light to desorb analytes from thermally conductive, carbonaceous sorbents, to be delivered to downstream analytical detectors. Since PTD’s conception, the theoretical framework and advances in sorbent fabrication have been investigated; however, further work is needed to produce a field-ready sampling device for use with PTD. As such, objectives of the present work were to design a PTD-compatible diffusive sampler prototype and characterize the prototype’s sampling efficiencies for toluene, n-hexane, trichloroethylene, and isopropyl alcohol. In pursuit of these objectives, the study empirically quantified the sampled masses of toluene, n-hexane, trichloroethylene, and isopropyl alcohol, at occupationally relevant air concentrations, to be 12.17 ± 0.06, 8.2 ± 0.1, 3.97 ± 0.06, and 8.0 ± 0.1 mg, respectively. Moreover, the analyte sampling efficiencies were found to be 2.2 ± 0.1, 1.7 ± 0.1, 1.2 ± 0.1, and 0.51 ± 0.05 (unitless) when comparing empirically (i.e., laboratory observed) sample mass values to theoretically predicted values. The sampling efficiencies and collected sample masses reported herein demonstrate the promising design of PTD-compatible diffusive samplers. When used in conjunction with the PTD method, the prototype samplers present strong evidence for improving analytical sensitivity in exposure assessments of VOCs in the workplace.