<p><strong>🎤Dr. Christopher Reid (Professor of Chemistry and Biochemistry at Bryant University in Rhode Island)</strong></p><p><strong>In this episode of Concentrating on Chromatography, host Dave Oliva sits down with Chris Reid to explore how chemical biology and LC-MS are being used to tackle one of the most urgent global challenges: antimicrobial resistance.</strong></p><p>As antibiotic resistance continues to rise—and new drug development struggles to keep pace—researchers are looking beyond traditional approaches. Instead of targeting how bacteria build their cell walls, Chris’s work focuses on how they break them down, opening the door to entirely new antimicrobial strategies.</p><h4><strong>What You’ll Learn in This Episode:</strong></h4><ul><li>Why antimicrobial resistance is accelerating globally</li><li>What peptidoglycan is and why it’s essential to bacterial survival</li><li>How targeting cell wall degradation differs from traditional antibiotics</li><li>The strategy behind designing small molecule probes and inhibitors</li><li>How LC-MS is used to analyze peptidoglycan fragments and enzyme activity</li><li>Key analytical challenges: complex mixtures, low-abundance species, and structural similarity</li><li>The importance of sample preparation and reproducibility in LC-MS workflows</li><li>How this research could lead to new antibiotic targets</li></ul><h3><strong>Video Transcription</strong></h3><h4><strong>The Growing Challenge of Antibiotic Resistance</strong></h4><p>According to Reid, antibiotic resistance is increasing across a broad spectrum of bacterial pathogens that were once readily treated with existing therapies. In some cases, clinicians must now rely on only a handful of last-line antibiotics, while resistance is also rising in diseases such as tuberculosis.</p><p>One of the major obstacles is the limited commercial incentive to develop entirely new antibiotics. Because bacterial resistance can emerge relatively quickly after a drug reaches the market, pharmaceutical companies often favor modifying existing antibiotics or combining them with resistance-modifying agents rather than investing in completely new drug classes. As a result, genuinely novel antibacterial targets remain urgently needed.</p><h4><strong>Why the Bacterial Cell Wall Remains an Attractive Target</strong></h4><p>The bacterial cell wall consists primarily of <strong>peptidoglycan</strong>, a highly cross-linked polymer that provides structural integrity, maintains cell shape, and enables bacterial growth and division.</p><p>Many widely used antibiotics—including the β-lactam antibiotics such as penicillins—target enzymes responsible for synthesizing or cross-linking peptidoglycan. These pathways have proven highly successful therapeutic targets because peptidoglycan is unique to bacteria and absent from human cells, minimizing unwanted effects on the host.</p><p>However, most existing antibiotics target only specific stages of peptidoglycan biosynthesis. Reid's research explores another part of this complex pathway: enzymes responsible for degrading the carbohydrate backbone of peptidoglycan during normal bacterial growth and remodeling. These enzymes may represent an underexplored class of antimicrobial targets capable of overcoming existing resistance mechanisms.</p><h4><strong>Targeting the Glycan Backbone</strong></h4><p>A key advantage of focusing on the carbohydrate backbone is its remarkable conservation across both Gram-positive and Gram-negative bacteria.</p><p>Whereas the peptide components of peptidoglycan vary considerably between bacterial species—and frequently acquire mutations associated with antibiotic resistance—the glycan backbone remains highly conserved and tolerates relatively few structural modifications.</p><p>This biological constraint makes enzymes acting on the glycan backbone particularly attractive targets. Reid's group developed a series of <strong>small-molecule probes and inhibitors</strong> designed to recognize enzymes known as <strong>N-acetylglucosaminidases</strong>, which cleave glycosidic bonds within peptidoglycan and generate soluble degradation products.</p><p>Rather than beginning with purified enzymes, the researchers adopted a <strong>top-down phenotypic screening strategy</strong>. Candidate compounds were first evaluated for their ability to inhibit bacterial growth before progressively narrowing the list of potential molecular targets through genetic studies, microscopy, enzyme assays, and biochemical characterization. This iterative workflow ultimately identified compounds capable of inhibiting the desired enzyme class while simultaneously providing valuable chemical probes for studying bacterial cell wall biology.</p><h4><strong>LC-MS as a Central Analytical Tool</strong></h4><p>Liquid chromatography coupled with mass spectrometry plays a central role throughout the project by enabling detailed characterization of structural changes occurring within peptidoglycan after bacterial cells are treated with candidate inhibitors.</p><p>Because intact peptidoglycan is an insoluble polymer, sample preparation begins with isolation of the bacterial cell wall through detergent extraction and differential centrifugation. Additional purification steps remove proteins, nucleic acids, and teichoic acids before enzymatic digestion converts the insoluble material into soluble fragments suitable for chromatographic analysis.</p><p>The resulting digest is analyzed by LC-MS to examine changes in the distribution of peptidoglycan fragments. Chromatographic retention times provide an immediate indication of changes in cross-linking, with larger oligomers such as trimers and tetramers generally eluting later than monomeric fragments. Mass spectrometry then confirms the identity of these fragments by measuring their intact molecular masses, while tandem MS experiments can provide further structural information when required.</p><h4><strong>Sample Preparation Determines Data Quality</strong></h4><p>Reid emphasized that sample preparation represents one of the most critical—and challenging—stages of the entire workflow.</p><p>Because peptidoglycan analysis involves multiple purification, digestion, and reduction steps, even minor procedural differences between samples can introduce analytical artifacts that complicate biological interpretation.</p><p>Maintaining strict consistency throughout sample preparation is therefore essential. Appropriate controls must accompany every experiment, ensuring that observed chromatographic and mass spectrometric differences truly reflect biological responses rather than experimental variability. The complexity of bacterial cell wall composition further increases the analytical challenge, as subtle differences in amino acid substitutions and low-abundance cross-linked species can complicate LC-MS data interpretation.</p><h4><strong>Chemical Biology for Future Antibiotic Discovery</strong></h4><p>Although the identified compounds may eventually serve as starting points for antibiotic development, Reid views them primarily as <strong>chemical biology tools</strong>.</p><p>By selectively inhibiting individual enzymes, these probes allow researchers to investigate previously unexplored aspects of bacterial cell wall remodeling that cannot easily be studied using classical genetic approaches alone.</p><p>The research team is now expanding this strategy by combining their probes with <strong>proximity-labeling proteomics and mass spectrometry</strong>, aiming to map protein interaction networks associated with bacterial cell wall degradation. Such studies may reveal entirely new antibacterial targets and provide deeper insight into the biological processes governing bacterial growth and division.</p><p>Ultimately, the work illustrates how integrating synthetic chemistry, microbiology, molecular biology, and advanced LC-MS can accelerate the search for innovative therapeutic strategies against antimicrobial resistance. As existing antibiotics become progressively less effective, multidisciplinary approaches such as these may play an increasingly important role in identifying the next generation of antibacterial targets.</p><blockquote><p><strong>This text has been automatically transcribed from a video presentation using AI technology. It may contain inaccuracies and is not guaranteed to be 100% correct.</strong></p></blockquote><blockquote><h4><strong>Concentrating on Chromatography Podcast</strong></h4><p>Dive into the frontiers of chromatography, mass spectrometry, and sample preparation with host David Oliva. Each episode features candid conversations with leading researchers, industry innovators, and passionate scientists who are shaping the future of analytical chemistry. From decoding PFAS detection challenges to exploring the latest in AI-assisted liquid chromatography, this show uncovers practical workflows, sustainability breakthroughs, and the real-world impact of separation science. Whether you’re a chromatographer, lab professional, or researcher you'll discover inspiring content!</p><p>You can find <strong>Concentrating on Chromatography Podcast </strong>in podcast apps:</p><ul><li><a target="_blank" rel="noopener noreferrer" href="https://open.spotify.com/show/1wZg67rCjoGju4yhqxI3tL"><strong>Spotify</strong></a></li><li><a target="_blank" rel="noopener noreferrer" href="https://podcasts.apple.com/tz/podcast/concentrating-on-chromatography/id1788429185"><strong>Apple podcast</strong></a></li><li><a target="_blank" rel="noopener noreferrer" href="https://podscan.fm/podcasts/concentrating-on-chromatography"><strong>podscan</strong></a></li></ul><p>and on <a target="_blank" rel="noopener noreferrer" href="https://www.youtube.com/@ChromatographyTalk/videos"><strong>YouTube channel</strong></a></p></blockquote>

 Fighting Antibiotic Resistance with LC-MS: Targeting Bacterial Cell Walls

<p><strong>This study compares a commercial ELISA assay with a validated UHPLC-MS/MS method for determining total ergot alkaloids in wheat and durum samples. In addition to method performance, the authors investigated cross-reactivity and matrix effects to explain differences between immunoassay and chromatographic results.</strong></p><p>While ELISA demonstrated good repeatability and is well suited for high-throughput screening, systematic biases were observed due to compound- and matrix-dependent cross-reactivity. The findings support ELISA as an effective screening tool, whereas UHPLC-MS/MS remains the preferred method for accurate quantification and regulatory confirmation of ergot alkaloids.</p><blockquote><h4><strong>The original article</strong></h4><h4><a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.jafc.6c05234"><strong>Comparative Evaluation of Total Ergot Alkaloids Determination by ELISA and UHPLC-MS/MS in Wheat: Implications of Cross-Reactivity and Matrix Effects</strong></a></h4><p>Chamali Kodikara*, Dainna Drul, Nandika Bandara, and Sheryl A. Tittlemier*</p><p>J. Agric. Food Chem. 2026, 74, 25, 20015–20027</p><p><a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1021/acs.jafc.6c05234">https://doi.org/10.1021/acs.jafc.6c05234</a></p><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/"><strong>CC-BY 4.0</strong></a></h6></blockquote><p><strong>Selected sections from the article follow. Formats and hyperlinks were adapted from the original.</strong></p><div><p>Ergot alkaloids (EAs) are a structurally diverse group of indole-derived mycotoxins produced primarily by phytopathogenic fungi of the genus <i>Claviceps</i>, most notably <i>Claviceps purpurea</i>. These fungi infect the flowering heads of cereal crops, replacing the developing grain with hardened fungal structures (sclerotia) that contain ergot alkaloids. Cereals such as rye, wheat, barley, oats, and triticale are particularly susceptible, with infection severity strongly influenced by environmental conditions during flowering, including rainfall and humidity. <a href="javascript:void(0);">(1−3)</a> Although improvements in agronomic practices and grain cleaning have reduced the prevalence of visible ergot sclerotia, ergot alkaloids can persist in cereals and cereal-based foods even in the absence of detectable sclerotia. This may occur because sclerotia can fragment during harvesting, handling, cleaning, or milling, producing small particles that are not visually detected but may still contribute ergot alkaloids to grain or processed products, continuing to pose food and feed safety concerns. <a href="javascript:void(0);">(4)</a> <a href="javascript:void(0);">(5)</a> Ergot alkaloids share a common tetracyclic ergoline backbone and occur as structurally related compounds, including ergometrine, ergotamine, ergosine, ergocristine, ergocryptine, and ergocornine, together with their corresponding C-8 epimers. These epimers occur as <i>R-</i> and <i>S-</i>configurations, commonly referred to as -ine and -inine forms, respectively. Epimerization at the C-8 position can occur during fungal metabolism and during sample extraction, storage, and analysis, complicating accurate quantification. <a href="javascript:void(0);">(6,7)</a> Although S-epimers were historically considered biologically inactive, recent evidence indicates that they may contribute to overall exposure and toxicity, supporting their inclusion in analytical and regulatory frameworks. <a href="javascript:void(0);">(3)</a></p><p>Dietary exposure to elevated levels of ergot alkaloids has been associated with a range of adverse health effects, collectively referred to as ergotism, including vasoconstriction, ischemia, neurological disturbances, and hallucinations. <a href="javascript:void(0);">(3)</a> These effects arise primarily from interactions with adrenergic, serotonergic, and dopaminergic receptors. <a href="javascript:void(0);">(8−10)</a> In response, regulatory limits for ergot alkaloids in food have been introduced or revised in several jurisdictions. In the European Union, maximum levels have been established for the sum of 12 ergot alkaloids in cereal milling products under Regulation (EU) 2021/1399, which was subsequently consolidated under Regulation (EU) 2023/915. This sum includes ergometrine, ergosine, ergotamine, ergocornine, ergocryptine, and ergocristine together with their corresponding -inine epimers, increasing the demand for reliable analytical methods to support routine monitoring and enforcement. <a href="javascript:void(0);">(1,11)</a></p><p>Liquid chromatography-tandem mass spectrometry (LC-MS/MS), particularly ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), is widely regarded as the reference technique for confirmatory determination of ergot alkaloids due to its sensitivity, selectivity, and ability to resolve epimeric forms. Recent methods routinely achieve low microgram-per-kilogram limits of quantification across a range of cereal matrices. <a href="javascript:void(0);">(12−17)</a> However, LC-MS/MS approaches are resource-intensive and typically confined to centralized laboratories, limiting their suitability for high-throughput screening or rapid decision-making in grain-handling and quality-control settings. Consequently, rapid screening methods, most notably enzyme-linked immunosorbent assays (ELISAs), are commonly employed as complementary tools to chromatographic analysis. <a href="javascript:void(0);">(18−21)</a> ELISAs offer reduced analysis time, simplified workflows, and lower per-sample costs, making them attractive for preliminary screening and sample triage. <a href="javascript:void(0);">(22−24)</a></p><p>In contrast to other regulated mycotoxins, however, the commercial availability of ELISAs for ergot alkaloids is limited. While multiple kits have been evaluated, performance has varied substantially across assays and matrices. <a href="javascript:void(0);">(1)</a> At present, the Randox Food Diagnostics Ergot Alkaloids ELISA is the only widely marketed microplate ELISA that quantifies the sum of 12 major ergot alkaloids, comprising ergometrine, ergosine, ergotamine, ergocornine, ergocryptine, and ergocristine together with their corresponding -inine epimers, consistent with the analyte scope used for EU maximum levels for ergot alkaloids in specified cereal products. <a href="javascript:void(0);">(25)</a></p><p>In addition, cereal matrix effects may influence antibody binding and signal generation, potentially resulting in biased quantification relative to LC-MS/MS reference methods. These limitations are particularly relevant given the compositional variability of ergot alkaloids across cereal species, geographic regions, and growing conditions. <a href="javascript:void(0);">(12)</a> Recent reviews emphasize the need for systematic, matrix-specific evaluation of immunoassay performance before such methods can be confidently integrated into regulatory or industrial monitoring programs. <a href="javascript:void(0);">(1,6,11)</a> However, independent evaluations of commercially available ergot alkaloid ELISAs, particularly those benchmarked against validated UHPLC-MS/MS methods using naturally infested wheat samples, remain limited.</p><p>In this context, we hypothesized that measurements of total ergot alkaloids obtained using a commercially available ELISA are influenced by matrix effects and antibody cross-reactivity, resulting in systematic differences compared to UHPLC-MS/MS, which provides compound-specific quantification. To test this, the objective of the present study was to conduct a comprehensive performance evaluation of a commercially available ELISA for the detection of ergot alkaloids in wheat, using UHPLC-MS/MS as a reference method. Specific aims included assessment of repeatability and intermediate precision, extraction efficiency and extract stability, the influence of test portion mass, method accuracy relative to UHPLC-MS/MS, and characterization of antibody cross-reactivity toward individual ergot alkaloids in both solvent and wheat matrix. The results provide data-driven guidance on the appropriate use of ELISA-based screening within tiered analytical strategies for regulatory monitoring and food safety decision-making.</p><h4><strong>2. Materials and Methods</strong></h4><h5><strong>2.3. UHPLC-MS/MS Reference Method</strong></h5><p>UHPLC-MS/MS analysis of ergot alkaloids was performed using the validated Canadian Grain Commission (CGC) method described by Tittlemier et al. (2015). Briefly, ground grain (10 g) was extracted with 50 mL of acetonitrile/aqueous ammonium carbonate (84:16, v/v; 3.03 mM ammonium carbonate) to provide alkaline extraction conditions, then shaken for 30 min and centrifuged at 2450<i>g</i> for 10 min at room temperature. An aliquot of extract (464 μL) was combined with internal standard solution (dihydroergotamine; 20 μL of 4 ng/μL) and aqueous ammonium carbonate (1536 μL), vortex-mixed, and filtered through a 0.45 μm polytetrafluoroethylene syringe filter before injection into the UHPLC-MS/MS system. As in the validated reference method, dihydroergotamine was added after extraction to correct for postextraction analytical variability; extraction recovery was evaluated during method validation. Chromatographic separation was achieved using a reversed-phase <strong>BEH C18 column</strong> (2.1 × 100 mm, 1.7 μm; Waters, Milford, MA, USA) with the autosampler maintained at 15 °C and the column at 30 °C. Mobile phases consisted of (A) 3.03 mM aqueous ammonium carbonate and (B) acetonitrile. The gradient program was as follows: initial, 75% A/25% B; 1.00 min, 60% A/40% B; 5.00 min, 40% A/60% B; 8.00 min, 22% A/78% B; 10.50–11.00 min, 10% A/90% B; and 13.00–16.00 min, 75% A/25% B, with a total run time of 16 min. Detection was performed using positive electrospray ionization in multiple reaction monitoring mode on a <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/554"><strong>Waters Xevo triple quadrupole mass spectrometer</strong></a> (Waters, Milford, MA, USA). Under the validated chromatographic conditions, dihydroergotamine did not coelute with ergotamine, ergotaminine, or the other target ergot alkaloids. Identification and quantification were based on retention-time criteria and compound-specific MRM transitions, thereby minimizing potential isotopic or coelution interference. Precautions to minimize epimerization, including controlled handling of standards and extracts and reduced light exposure, were followed as described in the reference method. UHPLC-MS/MS quantification was performed using analyte-specific, matrix-matched calibration curves prepared according to the validated CGC reference method, with calibration levels of 0.046, 0.2, 1, 2, 10, and 20 μg/kg. Dihydroergotamine was used as the internal standard, and concentrations were calculated from internal-standard-normalized analyte responses with method dilution factors applied. Total ergot alkaloid concentration was calculated as the arithmetic sum of all quantified ergot alkaloids and epimers included in the validated method. <a href="javascript:void(0);">(26)</a></p><h4><strong>3. Results and Discussion</strong></h4><h5><strong>3.4. Comparison of ELISA and UHPLC-MS/MS Results</strong></h5><p>For method comparison, UHPLC-MS/MS was used as the chemical reference method, providing compound-specific quantification of individual ergot alkaloids and their epimers. A total ergot alkaloid concentration was calculated as the arithmetic sum of all quantified alkaloids included in the method. This summed value represents a chemically defined total based on compound-specific quantification of each analyte, rather than an immunoreactivity-weighted response governed by antibody affinity. As such, the UHPLC-MS/MS total serves as a chemically defined comparator against which the immunoreactivity-weighted ELISA response can be interpreted. Agreement between the commercial ELISA and the validated UHPLC-MS/MS reference method was evaluated using wheat and durum wheat cargo samples (<i>n</i> = 102) collected over multiple crop years (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.jafc.6c05234#fig5">Figure 5</a>). Linear regression analysis demonstrated a positive association between ELISA and UHPLC-MS/MS results across the full concentration range, indicating that the ELISA was responsive to increasing ergot alkaloid levels. However, the regression slope deviated substantially from unity, with ELISA results systematically lower than UHPLC-MS/MS values, indicating an approximate 2-fold underestimation.&nbsp;</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/J_Agric_Food_Chem_2026_74_25_20015_20027_Figure_5_Linear_regression_analysis_comparing_total_ergot_alkaloid_concentrations_determined_by_ELISA_and_UHPLC_MS_MS_5d7b5c5c61.jpeg" alt="J. Agric. Food Chem. 2026, 74, 25, 20015–20027: Figure 5. Linear regression analysis comparing total ergot alkaloid concentrations determined by ELISA and UHPLC-MS/MS for wheat and durum wheat cargo samples (n = 102). Each point represents the mean of duplicate measurements (extracted from the same test portion) ELISA determinations for an individual cargo sample, plotted against the corresponding UHPLC-MS/MS result. Statistical analysis was performed using linear regression." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_J_Agric_Food_Chem_2026_74_25_20015_20027_Figure_5_Linear_regression_analysis_comparing_total_ergot_alkaloid_concentrations_determined_by_ELISA_and_UHPLC_MS_MS_5d7b5c5c61.jpeg 197w," sizes="100vw" width="992" height="784"></p><p>Bland-Altman analysis confirmed this proportional bias, showing a consistent negative mean difference between ELISA and UHPLC-MS/MS results across the concentration range (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.jafc.6c05234#fig6">Figure 6</a>). Importantly, the magnitude of disagreement did not increase randomly with concentration; rather, it reflected a systematic offset, indicating that the discrepancy was not driven by analytical imprecision or outliers but by fundamental differences in method response characteristics. This pattern indicates method-level bias rather than random analytical variability, which may arise from combined workflow effects including extraction, matrix response, and immunochemical cross-reactivity. The magnitude of the ELISA-UHPLC-MS/MS bias was substantially greater than the intermediate precision observed for the ELISA quality-control material, supporting the interpretation that the disagreement reflects systematic differences in method response rather than insufficient ELISA repeatability. Such behavior is well documented when immunoassays are compared with chromatographic methods for complex mycotoxin mixtures, including ergot alkaloids and other structurally diverse mycotoxins in cereals and feed. <a href="javascript:void(0);">(28,30,33)</a> These studies consistently report matrix- and profile-dependent bias in ELISA relative to LC-MS/MS, arising from differential antibody cross-reactivity and the summed immunoreactivity response of the assay, because ELISA produces an immunoreactivity-weighted total that depends on antibody affinity toward individual alkaloids and their relative abundance in the sample, whereas UHPLC-MS/MS quantifies compound-specific concentrations of each alkaloid and its epimers using compound-specific transitions and response factors, and total ergot alkaloid concentration is calculated as the sum of these targeted analytes. In contrast, ELISA produces an immunoreactivity-weighted total, determined by antibody affinity toward individual alkaloids and their competitive binding behavior within the assay format. Consequently, agreement between ELISA and UHPLC-MS/MS depends not only on total concentration, but also on the relative distribution of individual alkaloids within each sample. Although differences in extraction solvent composition and pH may influence ergot alkaloid recovery, stability, and epimeric distribution, each method was applied according to its intended analytical workflow. The ELISA was performed using the manufacturer-recommended acidic methanol/water extraction, whereas UHPLC-MS/MS was performed using the validated acetonitrile/aqueous ammonium carbonate extraction procedure. Therefore, the comparison reflects the performance of the complete methods as used in practice, rather than an isolated comparison of extraction solvents. The sequential extraction experiment further showed that repeating the ELISA extraction under the same kit conditions did not substantially increase the ELISA-measured response, supporting the adequacy of the kit extraction within the ELISA workflow while recognizing that it does not directly compare acidic and ammonium carbonate-based extraction conditions. Previous ELISA-LC-MS/MS comparison studies for ergot alkaloids have reported both under- and overestimation depending on assay design and matrix, including differences in alkaloid profile, cereal type, and antibody cross-reactivity. Turner et al. observed substantial overestimation of ergot alkaloids by ELISA relative to HPLC in rye field samples, attributed to strong antibody cross-reactivity toward alkaloids prevalent in rye matrices. Similar profile-dependent bias has also been reported in interlaboratory and method-comparison studies, <a href="javascript:void(0);">(33)</a> demonstrating that this behavior is not unique to a single data set.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/J_Agric_Food_Chem_2026_74_25_20015_20027_Figure_6_Bland_Altman_plot_comparing_ELISA_and_UHPLC_MS_MS_measurements_of_total_ergot_alkaloids_1be40cce50.jpeg" alt="J. Agric. Food Chem. 2026, 74, 25, 20015–20027: Figure 6. Bland-Altman plot comparing ELISA and UHPLC-MS/MS measurements of total ergot alkaloids for wheat and durum wheat cargo samples (n = 102)." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_J_Agric_Food_Chem_2026_74_25_20015_20027_Figure_6_Bland_Altman_plot_comparing_ELISA_and_UHPLC_MS_MS_measurements_of_total_ergot_alkaloids_1be40cce50.jpeg 230w," sizes="100vw" width="1437" height="977"></p><p>This study provides a comprehensive evaluation of a commercially available ELISA for total ergot alkaloids, using wheat samples as the primary application matrix, and integrates performance metrics with mechanistic insights into method behavior. While the assay demonstrated strong repeatability, calibration stability, and robustness to procedural factors such as test portion mass and extraction conditions, systematic differences relative to UHPLC-MS/MS were consistently observed. By linking these differences to compound-specific antibody cross-reactivity and matrix-dependent signal modulation, this work clarifies that ELISA-derived results reflect an immunochemically weighted response rather than a stoichiometric total. This distinction is critical for the appropriate interpretation of ELISA data and supports its use within tiered analytical strategies as a rapid screening tool, complemented by UHPLC-MS/MS for confirmatory quantification and regulatory decision-making.</p></div>

Comparative Evaluation of Total Ergot Alkaloids Determination by ELISA and UHPLC-MS/MS in Wheat: Implications of Cross-Reactivity and Matrix Effects

<p><strong>In the week of July 6, the following webinars await you in the field of liquid phase and especially HPLC and LC/MS.</strong></p><blockquote><h4><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinars"><strong>👉 DETAILS AND REGISTRATION IN THE WEBINARS SECTION</strong></a></h4><p><strong>👉 Search and filter in the largest global database</strong> with over <strong>5 500 GC, LC, MS and spectroscopy webinars</strong>.</p></blockquote><h5><strong>1. Waters Corporation: Characterizing Next-Generation Antibody Therapeutics: LC Strategies for Multispecifics, ADCs &amp; AOCs</strong></h5><ul><li>Tu, 7.7.2026 11:00 CEST</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/6317">Registration</a></li></ul><p>In this webinar, we share a pragmatic characterization roadmap using LC-based methods across intact, subunit, and peptide-mapping workflows.</p><h5><strong>2. Separation Science: Advances in Antibiotic Extraction from Water: An Automated SPE Approach</strong></h5><ul><li>We, 8.7.2026 09:00 CEST</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/6319">Registration</a></li></ul><p>Streamline water analysis workflows and gain practical insights for modern environmental monitoring.</p><h5><strong>3. SCIEX: Analysis of per- and polyfluoroalkyl substances (PFAS) in food substances using LC-MS/MS solutions</strong></h5><ul><li>We, 8.7.2026 15:00 CEST</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/6322">Registration</a></li></ul><p>Master PFAS analysis in food safety. Learn how SCIEX LC-MS/MS solutions and QTRAP workflows overcome analytical challenges to ensure accurate and compliant result confirmation.</p><h5><strong>4. Wiley: From liquids to solids: expand what your UV-Vis-NIR Spectrometer can do</strong></h5><ul><li>We, 8.7.2026 16:00 CEST</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/6367">Registration</a></li></ul><p>Discover how the Agilent Cary UV-Vis-NIR spectrometer, together with Specac accessories, enables reliable analysis of liquids, powders, films, pellets, and highly scattering solid samples.</p><h5><strong>5. Thermo Fisher Scientific: Advanced tools to maximize your sample throughput with Chromeleon Software and Vanquish UHPLC</strong></h5><ul><li>Th, 9.7.2026 11:00 CEST</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/6326">Registration</a></li></ul><p>Learn how Chromeleon software and the Vanquish Duo UHPLC system streamline sample analysis, automate routine workflows, increase throughput, and reduce errors through practical demonstrations.</p><h5><strong>6. Bruker: 4D-Metabolomics™ in Action: Real-World Strategies for Deep Discovery and Confident Annotation</strong></h5><ul><li>Th, 9.7.2026 17:00 CEST</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/6328">Registration</a></li></ul><p>Explore how next-generation mass spectrometry technologies, ion mobility, and computational tools are helping researchers move from complex datasets to confident insight.</p><h5><strong>7. Waters Corporation: Cracking the Code on Nitrogen Methods</strong></h5><ul><li>Th, 9.7.2026 17:00 CEST</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/6327">Registration</a></li></ul><p>Learn the fundamentals of nitrogen analysis for wastewater testing. Explore analytical methods, QA/QC, sample handling, compliance reporting, and troubleshooting for accurate environmental monitoring.</p><h5><strong>8. SelectScience: Next-generation metabolomics: From annotation to discovery at scale</strong></h5><ul><li>Th, 9.7.2026 17:00 CEST</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/6281">Registration</a></li></ul><p>Explore how next-generation mass spectrometry, ion mobility, and advanced computational tools accelerate confident small-molecule annotation and discovery in metabolomics.</p><h5><strong>9. SCIEX: LC-MS/HRMS Approaches for Monitoring Organic Micropollutants in Wastewater and Environmental Systems</strong></h5><ul><li>Fr, 10.7.2026 15:00 CEST</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/6370">Registration</a></li></ul><p>Discover how advanced LC-MS/HRMS workflows enable trace-level detection of organic micropollutants, suspect and non-target screening, and environmental monitoring of wastewater systems.</p>

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Waters ACQUITY Advanced Polymer Chromatography (APC) Calibration Standards Kits

Eliminate manual preparation of custom standard calibration mixes with ACQUITY Advanced Polymer Chromatography (APC) Calibration Standards.

<div><div><h3><strong>Frequent calibration for greater confidence in your results</strong></h3></div></div><div><div><p><strong>Eliminate manual preparation of custom standard calibration mixes with ACQUITY Advanced Polymer Chromatography (APC) Calibration Standards, which provide the right number of data points for your targeted molecular weight (MW) range. ACQUITY APC Calibration Standards are specifically designed to match the molecular weight range of the </strong><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1950"><strong>ACQUITY APC Columns</strong></a><strong>.</strong></p><p>ACQUITY APC polymethylmethacrylate and polystyrene standards are configured into <strong>Low</strong>, <strong>Middle</strong>, and <strong>High Molecular Weight Calibration Kits</strong>, as well as a convenient<strong> Method Development Kit </strong>that includes the full separation range of all three kits combined. These chromatography standards are designed to provide a maximum range of narrow standard data points for a specific column set or molar mass range.</p><p>With ACQUITY APC Calibration Standards, you can conduct calibration with<strong> 3-5x shorter cycle times</strong>, enabling you to run more replicates and more easily include calibration with each test set. With increased calibration frequency, you can have higher confidence in the accuracy of each test run.</p><div><div><ul><li><strong>Simple and easy</strong>&nbsp;to use by adding solvent and injecting</li><li><strong>Shorter preparation time</strong> resulting in faster calibration cycle time</li><li><strong>Greater confidence</strong> in molecular weight determination of samples</li><li><strong>Reduce variances</strong> in analysis providing increased product quality</li></ul><div><div><p><strong>Recommended Use:&nbsp;</strong>For <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/194"><strong>advanced polymer chromatography </strong></a>calibration.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Waters_ACQUITY_Advanced_Polymer_Chromatography_APC_Calibration_Standards_Kits_2_1e32010bc1.jpg" alt="Waters ACQUITY Advanced Polymer Chromatography (APC) Calibration Standards Kits: The ACQUITY Advanced Polymer Chromatography (APC) Calibration Standards are available in polystyrene and polymethylmethacrylate configured into Low, Middle, and High Molecular Weight Calibration Kits. " srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Waters_ACQUITY_Advanced_Polymer_Chromatography_APC_Calibration_Standards_Kits_2_1e32010bc1.jpg 245w," sizes="100vw" width="1024" height="565"></p></div></div></div></div></div></div>

Products focused on Standards and chemicals distributed by Waters Corporation (Europe) - page 1

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