Join us for a fascinating conversation with Dr. Subhoja Chakraborty from the University of Central Florida, whose cutting-edge research targets the global challenge of malaria drug resistance. Dr. Chakraborty shares her journey from structure-based drug design during her PhD to her recent collaborative work repurposing human kinase inhibitors as rapid, selective antimalarials against drug-resistant Plasmodium falciparum strains.<h4>In this episode, you'll learn:</h4><ul><li>How structure-guided approaches reveal potential drug targets, including cysteine proteases like falcipain-2, and kinases implicated in malaria's complex life cycle.</li><li>The power of repurposing kinase inhibitors originally developed for cancer and other diseases, focusing on compound 12, which blocks hemozoin formation and protein kinase 6—key steps in parasite survival.</li><li>Lab techniques such as affinity, gel filtration, and size exclusion chromatography for recombinant protein purification—and how troubleshooting is crucial for high-yield, stable complexes.</li><li>Advances in mass spectrometry for characterizing protein interactions, validating drug targets, and mapping molecular pathways pivotal to malaria therapeutics.</li><li>Tips and lessons for new researchers facing the challenges of sample preparation, complex protocols, and working as part of a collaborative team.</li></ul>Dr. Chakraborty’s insights bridge the gap between basic science and translational drug discovery, offering hope for more effective, targeted malaria treatments in a world where resistance to frontline therapies threatens millions.<h4>Referenced Papers:</h4><ul><li>"Plasmodium falciparum protein kinase 6 and hemozoin formation are inhibited by a type II human kinase inhibitor exhibiting antimalarial activity" (Cell Chemical Biology, 2025)</li><li>"New insights of falcipain 2 structure from Plasmodium falciparum 3D7 strain" (BBRC, 2022)</li><li>"Structure-Based Optimization of Protease−Inhibitor Interactions to Enhance Specificity of Human Stefin‑A against Falcipain‑2 from the Plasmodium falciparum 3D7 Strain" (Biochemistry, 2023)</li></ul>If you’re a student, scientist, or simply passionate about advances in infectious disease research, this episode offers actionable insights, inspiring advice, and a front-row seat to innovation in combating malaria.<h3>Video Transcription</h3><h4>From Structural Biology to Drug Discovery: Chromatography and Mass Spectrometry in Malaria Research</h4><h5>Introduction</h5>In this discussion, Subhoja shares insights into her research journey, focusing on malaria drug discovery and the role of modern analytical techniques in biological and biomedical research. The conversation is aimed primarily at undergraduate students and early-career researchers interested in chemistry, biotechnology, and life sciences.<h5>Research Focus: Malaria Drug Discovery and Kinase Targets</h5>Subhoja is currently involved in malaria drug discovery research at the University of Central Florida, where she has been working since beginning her postdoctoral position two years ago. Her earlier PhD research focused on structure-based drug design in malaria, using a combination of in silico approaches, recombinant protein expression, and X-ray crystallography to determine precise three-dimensional structures of target proteins and their inhibitors.This structural perspective provided a foundation for her current work, which centers on drug discovery through compound screening and repurposing. A recent publication from her laboratory explores the use of repurposed mammalian CDK-like kinase inhibitors as potential antimalarial agents. While such kinase inhibitors are well known in cancer and cardiovascular research, their application to malaria targets represents a novel and promising approach.Kinases are attractive drug targets because of their central role in cell signaling and growth pathways. By targeting specific kinases involved in different stages of the malaria parasite life cycle—whether asexual growth, gametocytogenesis, or differentiation—it may be possible to significantly inhibit parasite growth and progression.<h5>Chromatography in Protein Expression and Purification Workflows</h5>Chromatography plays a critical role throughout Subhoja’s research. Her experience spans from basic chromatography techniques during her early training to advanced protein purification workflows using affinity chromatography, gel filtration (size exclusion chromatography), and ion exchange chromatography.Recombinant proteins are routinely purified using affinity resins such as nickel or cobalt, followed by further purification to remove contaminants. Fast Protein Liquid Chromatography (FPLC) enables compact, stepwise purification workflows suitable for producing proteins for in vitro assays.A recurring challenge in this process is the expression of high-molecular-weight proteins, which often accumulate in insoluble fractions or inclusion bodies. Careful selection of expression vectors, host systems, and induction conditions is therefore essential to maximize yield and solubility.<h5>Integrating Size Exclusion Chromatography into the Workflow</h5>Size exclusion chromatography (SEC) is typically used after affinity purification to further improve protein purity. Following elution with imidazole or glutathione, desalting is required to prevent buffer components from interfering with downstream assays. This is often achieved using desalting columns such as G-25 or PD-10.To remove lower-molecular-weight contaminants, finer SEC media—such as Superdex or Sephacryl columns—are employed. Concentration steps using molecular-weight cut-off filters are then applied to obtain the desired protein concentration for functional studies.These iterative purification and troubleshooting steps are a routine part of protein biochemistry and reflect the importance of methodical optimization and careful validation.<h5>The Role of Mass Spectrometry in Biomolecular Characterization</h5>Mass spectrometry is a key analytical tool in Subhoja’s research pipeline, particularly for target identification and validation. In both malaria and cancer research, MS is used alongside chromatography, immunoprecipitation, and pull-down assays to study protein interactions and molecular recognition events.Affinity-based mass spectrometry enables the identification of binding partners and interactors, whether studying proteins, long non-coding RNAs, or protein complexes. Techniques such as native MS, tandem affinity purification, and proximity labeling (e.g., TurboID-based workflows) provide deeper insights into molecular networks and signaling pathways.These approaches are essential for understanding how candidate drug targets function within complex biological systems.<h5>Sample Preparation Challenges in Biological Research</h5>Sample preparation remains one of the most challenging aspects of biological experimentation. Whole-cell lysates contain proteases, nucleases, and other components that can rapidly degrade target molecules. Preventing degradation requires minimizing preparation time, maintaining low temperatures, and using appropriate inhibitor cocktails.Reproducibility is also critical: biological experiments require multiple replicates, and variability is often unavoidable. Careful handling, protocol optimization, and continuous troubleshooting are essential to ensure reliable results, whether preparing samples for chromatography, mass spectrometry, sequencing, or immunoprecipitation.<h5>Advances in Chromatography and MS for Malaria Research</h5>Modern advances in chromatography and mass spectrometry significantly enhance malaria research by enabling precise target identification, quantification, and functional characterization. Drug discovery workflows begin with construct design and recombinant expression, followed by purification and interaction studies.In malaria research, stage-specific parasite biology requires careful extraction and analysis of proteins from different life cycle stages. Tandem affinity MS, immunoprecipitation, and in vivo validation studies help confirm target relevance and therapeutic potential.Recent work on repurposed kinase inhibitors has shown promising results, including inhibition of hemozoin formation—a key detoxification pathway for the malaria parasite—highlighting the potential of such compounds for further development.<h5>Malaria, Drug Resistance, and Global Impact</h5>Malaria remains a major global health burden, with over 600,000 deaths annually and widespread drug resistance complicating treatment. Artemisinin resistance, particularly associated with mutations in the K13 propeller domain, has driven the search for new targets and therapies.During her PhD, Subhoja focused on falcipain-2, a cysteine protease involved in hemoglobin degradation within the parasite. This pathway is critical for parasite survival and has emerged as a promising drug target. Her work revealed that falcipain-2 operates within a larger protein complex responsible for hemoglobin processing and amino acid release.Understanding these molecular mechanisms is essential for developing robust, stage-specific antimalarial strategies.<h5>Advice for Early-Career Researchers</h5>For researchers just starting out, Subhoja emphasizes the importance of hands-on experience. Working directly with cells, lysates, and analytical tools is essential for truly understanding experimental systems. Failure is an inherent part of research, and perseverance is key.Motivation, teamwork, careful sample handling, and thorough preparation all contribute to long-term success. Reading extensively, critically evaluating one’s own work, and appreciating incremental progress are vital aspects of a sustainable research career.Every successful experiment—no matter how small—represents meaningful progress and contributes to the broader goals of science and medicine.<h5>Closing Remarks</h5>The discussion highlights how interdisciplinary approaches combining chromatography, mass spectrometry, structural biology, and biochemistry are driving advances in malaria drug discovery. Through careful experimental design, analytical rigor, and collaborative teamwork, researchers can address complex biological challenges and contribute to global health solutions.<blockquote>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.</blockquote><blockquote><h4>Concentrating on Chromatography Podcast</h4>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!You can find Concentrating on Chromatography Podcast in podcast apps:<ul><li><a target="_blank" rel="noopener noreferrer" href="https://open.spotify.com/show/1wZg67rCjoGju4yhqxI3tL">Spotify</a></li><li><a target="_blank" rel="noopener noreferrer" href="https://podcasts.apple.com/tz/podcast/concentrating-on-chromatography/id1788429185">Apple podcast</a></li><li><a target="_blank" rel="noopener noreferrer" href="https://podscan.fm/podcasts/concentrating-on-chromatography">podscan</a></li></ul>and on <a target="_blank" rel="noopener noreferrer" href="https://www.youtube.com/@ChromatographyTalk/videos">YouTube channel</a></blockquote>

Affinity, Gel Filtration, Size Exclusion Chromatography: Repurposing Kinase Inhibitors for Malaria

In the week of February 9, the following webinars await you in the field of liquid phase and especially HPLC and LC/MS.<blockquote><h4><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinars">👉 DETAILS AND REGISTRATION IN THE WEBINARS SECTION</a></h4>👉 Search and filter in the largest global database with over 5 000 GC, LC, MS and spectroscopy webinars.</blockquote><h5>1. SelectScience: High-Throughput Stability Screening Strategies for Antibody Formulation</h5><ul><li>Tu, 10.2.2026 17:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5807">Registration</a></li></ul>Learn how high-throughput DLS/SLS and rapid-screening DSC accelerate stability assessment of high-concentration antibody formulations, enabling faster, data-driven biologics development.<h5>2. Phenomenex: Big Scale, Big Wins – Prep Chromatography Explained</h5><ul><li>We, 11.2.2026 10:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5793">Registration</a></li></ul>Learn how to scale analytical methods to preparative HPLC, optimize loading capacity, and understand the limits of preparative columns for pharmaceutical applications.<h5>3. ALS Czech Republic: PFAS in Food &amp; Food Contact Material</h5><ul><li>We, 11.2.2026 15:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5816">Registration</a></li></ul>Get a practical overview of PFAS in food and food contact materials, including EU and US regulations, key analytical challenges, and reliable PFAS testing strategies.<h5>4. New Food Magazine: The Science of Next-Gen Ingredients – Fermentation, Formulation and Function</h5><ul><li>We, 11.2.2026 16:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5720">Registration</a></li></ul>Explore how fermentation-driven innovation is transforming functional food ingredients and how advanced analytics optimize flavour, functionality, and stability.<h5>5. SCIEX: Accurate Mass Fundamentals – Interpreting and Applying Your Data</h5><ul><li>We, 11.2.2026 19:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5772">Registration</a></li></ul>Session 3 focuses on interpreting and applying accurate mass data to confirm compound identity, move beyond basic quantitation, and troubleshoot results for confident reporting.<h5>6. Agilent Technologies: Process Analytical Techniques – Online HPLC for Real-Time Monitoring and Control of Bioprocesses</h5><ul><li>Th, 12.2.2026 06:30 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5834">Registration</a></li></ul>Discover how PAT HPLC enables near-real-time monitoring of critical quality attributes in bioprocessing, with a case study on charge-variant control by cation-exchange chromatography.<h5>7. Thermo Fisher Scientific: Introducing the Orbitrap Excedion Pro Hybrid MS</h5><ul><li>Th, 12.2.2026 11:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5889">Registration</a></li></ul>Discover the new Orbitrap Exploris Pro with expanded ETD/EThcD capabilities for confident biopharmaceutical characterization, including intact proteins, PTMs, ADCs, and large biomolecules.<h5>8. Waters Corporation: Planning Your NuGenesis Upgrade – Insights and Best Practices for a Smooth Transition</h5><ul><li>Th, 12.2.2026 19:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5833">Registration</a></li></ul>Learn how to plan a successful NuGenesis upgrade, transition to Windows 11, and unlock new capabilities such as dashboards for real-time operational insights.<h5>9. Thermo Fisher Scientific: Comprehensive Analytical Strategies for Peptide Therapeutics and GLP-1 Agonists with Agilent</h5><ul><li>Th, 12.2.2026 19:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5814">Registration</a></li></ul>Explore analytical workflows for peptide therapeutics, including method development, peptide mapping, GLP-1 QC, and LC-MS strategies across Agilent platforms.<h5>10. Agilent Technologies: Moving from R&amp;D and Limited QC on a UV-Vis-NIR Instrument to Large-Scale QC Using an Autosampler</h5><ul><li>Th, 12.2.2026 20:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/2104">Registration</a></li></ul>This webinar covers practical aspects of adding and using an autosampler to maximize UV-Vis-NIR QC workflows at scale.<h5>11. Agilent Technologies: LC Method Transfer – Hidden Challenges &amp; Absolute Solution</h5><ul><li>Fr, 13.2.2026 06:30 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5787">Registration</a></li></ul>Discover why LC method transfer between legacy and modern systems is challenging, which hidden parameters affect retention and peak shape, and how to achieve robust, reliable results.

Webinars LabRulezLCMS Week 07/2026

Charge detection mass spectrometry (CDMS) allows direct mass determination of individual ions and is increasingly used to study heterogeneous biological samples. This work demonstrates the use of Orbitrap-based CDMS/Direct Mass Technology (DMT) for quantitative analysis of transthyretin (TTR) tetramer samples below 100 kDa, extending CDMS beyond its traditional qualitative role.DMT resolved wild-type and C-terminally modified TTR homotetramers, as well as hybrid tetramers, enabling kinetic analysis of subunit exchange and stability. The approach also quantified thyroxine binding to TTR variants, revealing differences in binding affinity linked to C-terminal modification. By separating overlapping m/z signals through charge measurement, CDMS enables accurate mass and abundance determination, highlighting its potential for quantitative analysis of complex protein systems.<blockquote><h4>The original article</h4><h4><a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.analchem.5c05771">Dissecting Heterogeneous Populations of Protein-Complex Samples Using Direct Mass Technology</a></h4>Robert L. Rider, Jared Hampton, Zhenyu Xi, Carter Lantz, Sangho D. Yun, Weijing Liu, Rosa Viner, Arthur Laganowsky, and David H. Russell*Anal. Chem. 2025, 97, 49, 27057–27063<a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1021/acs.analchem.5c05771">https://doi.org/10.1021/acs.analchem.5c05771</a><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/">CC-BY 4.0</a></h6></blockquote>Selected sections from the article follow. Formats and hyperlinks were adapted from the original.Transthyretin (TTR) is a homotetrameric transport protein that circulates in plasma and cerebrospinal fluid, delivering thyroxine (T4) and retinol-binding protein–vitamin A complexes. <a href="javascript:void(0);">(1)</a> The stability of the TTR tetramer is central to its physiological role because dissociation into monomers can initiate misfolding and amyloid formation, leading to systemic or hereditary transthyretin amyloidosis. <a href="javascript:void(0);">(2)</a> Subunit exchange between wild-type (WT) and variant TTR proteoforms, including disease-associated mutations such as V30M and V122I, have been implicated in amyloid progression by generating hybrid tetramers (tetramers containing WT and mutant subunits) with altered stabilities. <a href="javascript:void(0);">(3,4)</a> Ligand binding, particularly at the two thyroxine-binding sites located at the dimer–dimer interface, can kinetically stabilize the tetramer and modulate amyloidogenicity. <a href="javascript:void(0);">(5,6)</a> Accurate measurement of both subunit exchange kinetics and ligand binding stoichiometry is therefore critical for elucidating the TTR dynamics and stability.Affinity or sequence tags are widely employed in protein expression, purification, or detection. <a href="javascript:void(0);">(7,8)</a> While these tags are often assumed to be inert, their influence on protein structure and dynamics are rarely examined in detail. <a href="javascript:void(0);">(9,10)</a> Protein tags at the N- and C-terminus of TTR have been shown to have differing gas phase stabilities from those of WT-TTR. <a href="javascript:void(0);">(11)</a> The C-terminus is of particular interest because this region participates in the dimer–dimer interface that governs tetramer stability. <a href="javascript:void(0);">(11,12)</a> Characterizing how the C-terminal tag (CT) (-ASGENLFYQ) affects TTR’s solution stability and ligand binding is not only relevant for understanding TTR dynamics but also provides an example of how expression tags can alter protein dynamics. <a href="javascript:void(0);">(13)</a>Native mass spectrometry (nMS) has been invaluable for characterizing protein complexes, <a href="javascript:void(0);">(14)</a> yet conventional nMS often struggles with heterogeneous samples where overlapping charge state distributions and adduct heterogeneity limit resolution and quantitation. <a href="javascript:void(0);">(15)</a> Charge detection mass spectrometry (CDMS) addresses these limitations by independently measuring the charge and m/z of individual ions, enabling the direct determination of molecular mass and abundance. Development of CDMS has largely focused on achieving higher mass resolution <a href="javascript:void(0);">(16)</a> and extending measurements toward assemblies into the GDa range. <a href="javascript:void(0);">(17,18)</a> However, there is untapped utility for CDMS experiments other than mass and proteoform determination. Jordan et al. showed the capability to assess conformational heterogeneity of mAb aggregates using the added charge dimension that CDMS provides. <a href="javascript:void(0);">(19)</a> The current work demonstrates that CDMS can separate proteoforms with overlapping m/z values based on charge and quantify their relative abundances in complex mixtures. While nMS is already a highly quantitative technique, our results establish CDMS as an equally powerful tool for quantitative analysis in heterogeneous systems. <a href="javascript:void(0);">(20,21)</a>Here, we apply Orbitrap-based CDMS/Direct Mass Technology (DMT) using the selective temporal overview of resonant ions (STORI) approach <a href="javascript:void(0);">(22,23)</a> to quantitatively compare WT-TTR and CT-TTR, focusing on two biologically relevant properties: tetramer stability assessed via subunit exchange kinetics and ligand-binding affinity. Conventional nMS cannot fully resolve the overlapping charge states of WT- and CT-TTR or their ligand-bound states. However, DMT can resolve these species by directly measuring the mass (m/z × charge), enabling quantitation of all proteoforms. The data reveal that the CT tag alters tetramer stability and thyroxine-binding affinity, demonstrating the structural sensitivity of TTR to modifications at its C-terminus. More broadly, this work demonstrates the impact that protein tags can have on native protein interactions and highlights the broader utility of quantitative CDMS for probing heterogeneous biological samples.<h4>Experimental Section</h4><h5>Data Collection</h5>All experiments were conducted on a <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/560">Thermo Scientific Q-Exactive UHMR</a> with added DMT capabilities (Bremen, Germany). Before DMT, mass spectra were collected at various resolving powers (6–200k) for each sample, with the instrument parameters reported in the Supporting Information (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acs.analchem.5c05771/suppl_file/ac5c05771_si_001.pdf">Table S1</a>). For DMT experiments, the trapping gas pressure in the HCD cell was reduced to 0.3–0.8 to attenuate the signal intensity to a single ion level, as well as decreasing the UHV pressure to assist ion retention through the entire transient of Orbitrap analysis. We observed no significant difference between mass spectra collected at various HCD cell pressures (Supporting Information, <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acs.analchem.5c05771/suppl_file/ac5c05771_si_001.pdf">Figure S1</a>). For DMT collection, automated ion control (AIC) and 100% target density were used with 200k resolving power.<h4>Results and Discussion</h4>CDMS has emerged as a powerful tool for analyzing heterogeneous biomolecular samples, enabling accurate, direct mass determination by simultaneously measuring the charge and m/z for individual ions. While CDMS has been widely applied for qualitative analyses, its potential for quantitative and less than MDa applications remains underexplored. <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.analchem.5c05771#fig1">Figure 1</a>A shows the theoretical mass spectrum of WT-TTR (14+ to 16+) and CT-TTR (15+ to 17+) homotetramers, where the two proteoforms become increasingly resolved as the charge states increase (&lt;3900 m/z). <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.analchem.5c05771#fig1">Figure 1</a>B zooms in on the 14+ (WT) and 15+ (CT) charge states, highlighting their strong overlap, which prevents accurate deconvolution of the proteoforms by conventional methods. <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.analchem.5c05771#fig1">Figure 1</a>C displays theoretical distributions for 0, 1, and 2 T4 bound states of both WT- and CT-TTR tetramers, where &lt;3900 m/z has observable separation between all proteoforms. However, for the 14+ and 15+ charge states of WT- and CT-TTR, respectively, the 0 T4- and 1 T4-bound populations overlap (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.analchem.5c05771#fig1">Figure 1</a>D). Furthermore, commonly adducted species (Na+, K+, and Zn2+) observed in experimental spectra broaden these distributions, making it increasingly difficult to distinguish and deconvolute the proteoforms (see <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acs.analchem.5c05771/suppl_file/ac5c05771_si_001.pdf">Figure S2</a>). Here, we employ Orbitrap-based CDMS/DMT to overcome this m/z overlap to resolve and quantify hybrid tetramer formation and T4 binding.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Anal_Chem_2025_97_49_27057_27063_Figure_1_A_Theoretical_mass_spectra_of_WT_TTR_and_CT_TTR_homotetramers_47232849d9.jpg" alt="Anal. Chem. 2025, 97, 49, 27057–27063: Figure 1. (A) Theoretical mass spectra of WT-TTR and CT-TTR homotetramers. (B) Zoomed-in view of the 14+ WT-TTR and 15+ CT-TTR distributions to show the large overlap of the proteoforms. (C) Theoretical mass spectra of WT-TTR and CT-TTR homotetramers with thyroxine (T4) binding. (D) Zoomed-in view of the 14+ WT-TTR and 15+ CT-TTR distributions where the 0 and 1 T4 have overlapping distributions. These theoretical distributions do not contain any commonly adducted species (Na+, K+, Zn2+), which broaden the distributions and create more overlap even for the proteoforms in the range 3300–3900 m/z (see Figure S2)." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Anal_Chem_2025_97_49_27057_27063_Figure_1_A_Theoretical_mass_spectra_of_WT_TTR_and_CT_TTR_homotetramers_47232849d9.jpg 187w," sizes="100vw" width="1417" height="1182"><h5>Thyroxine Binding to TTR Homotetramers</h5>Thyroxine is the less active form of a thyroid hormone important for metabolism that binds to TTR for transport throughout plasma and cerebral spinal fluid. <a href="javascript:void(0);">(31)</a> Turnover of T4 into T3 (active) occurs after dissociation, where it can then modulate gene expression via binding to nuclear receptors. <a href="javascript:void(0);">(32)</a> The TTR tetramer gains substantial stability as it binds up to 2 T4 at the tetramer interface, decreasing tetramer dissociation and SUE. <a href="javascript:void(0);">(33)</a> This has been shown previously to decrease the amyloidogenic rate of TTR, which led to tafamidis (similar in structure to T4) to be designed and is currently the only drug that is approved for clinical treatment of TTR amyloidosis. <a href="javascript:void(0);">(34)</a> Measuring the difference in binding affinity between TTR proteoforms may provide insight into regions of TTR or TTR intermolecular/intramolecular interactions that are important for binding of small molecules such as tafamidis and T4.DMT was further applied to quantify T4 binding to WT- and CT-TTR homotetramers, highlighting the technique’s utility in probing protein–ligand interactions. <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.analchem.5c05771#fig3">Figure 3</a>A shows a representative mass spectrum of TTR homotetramers in the presence of T4. While ligand-bound species can be observed, homotetramers cannot be confidently resolved across the entire 3000–5000 m/z range. By leveraging the charge-resolving capabilities of DMT, we achieve separation of the homotetramers (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.analchem.5c05771#fig3">Figure 3</a>B,C) and the 0, 1, and 2 ligand-bound states. The 2D plot clearly shows the gain in resolution achieved when charge is simultaneously measured with m/z by separating the 14+ and 15+ charge states for WT and CT, respectively, in the range 3900–4200 m/z. Additionally, using ion mobility does not provide the same kind of 2D resolution due to the similarity in arrival times for the homotetramer proteoforms, as evidenced by <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acs.analchem.5c05771/suppl_file/ac5c05771_si_001.pdf">Figures S4 and S5</a> (see the Supporting Information). These data provide evidence that when ion mobility is able to separate out species that overlap in m/z yet differ in mobility, CDMS could be an alternative or used complementarily since the species likely also differ in charge.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Anal_Chem_2025_97_49_27057_27063_Figure_3_A_Mass_spectra_of_WT_TTR_and_CT_TTR_homotetramers_with_thyroxine_binding_61b1e98a94.jpg" alt="Anal. Chem. 2025, 97, 49, 27057–27063: Figure 3. (A) Mass spectra of WT-TTR and CT-TTR homotetramers with thyroxine binding. Ligand binding can be resolved, but homotetramers cannot be confidently identified. Charge states labeled are for WT; CT is always one charge state higher at the same m/z range. (B) DMT heatmap resolving WT-TTR and CT-TTR homotetramers with the additional measurement of charge. (C) Deconvoluted mass spectrum from DMT analysis. Both homotetramers and their ligand binding are resolved, and fit for analysis is shown in red. (D) Mole fraction of each homotetramer and their thyroxine binding species. Error bars represent the standard deviation of replicates (n = 3). The significance for each ligand state is in respect to the left adjacent state. *p &lt; 0.05." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Anal_Chem_2025_97_49_27057_27063_Figure_3_A_Mass_spectra_of_WT_TTR_and_CT_TTR_homotetramers_with_thyroxine_binding_61b1e98a94.jpg 181w," sizes="100vw" width="1266" height="1094"><h4>Conclusion</h4>This work demonstrates that quantitatively, Orbitrap-based CDMS/DMT can determine differences in protein-complex stability and ligand binding. By directly comparing WT- with CT-TTR, we show that the CT tag accelerates tetramer dissociation while enhancing T4 binding affinity. These results indicate that the C-terminus, located at the dimer–dimer interface, plays a more significant role in TTR stability and ligand recognition than previously appreciated. <a href="javascript:void(0);">(12)</a> Even the addition of a short peptide sequence perturbs noncovalent interactions at the interface, likely altering solvent accessibility, and the dynamics of the thyroxine binding channel. <a href="javascript:void(0);">(37,54)</a> Such findings underscore the importance of evaluating how seemingly minor sequence modifications, such as affinity tags, can influence fundamental biophysical properties.Beyond TTR, this work positions quantitative CDMS as a broadly applicable strategy for analyzing heterogeneous protein systems, where charge domain separation overcomes the resolution limits of m/z domain measurements in traditional nMS experiments. While much of the field has emphasized extending CDMS to ultrahigh masses and maximal resolution, <a href="javascript:void(0);">(16,18)</a> our results highlight the underexplored potential of applying the method in the 1000–10,000 m/z range common to nMS experiments. This capability is directly relevant to heterogeneous membrane protein complexes, which often display broad distributions of oligomeric states, PTMs, lipid, and ligand adducts that complicate spectra. <a href="javascript:void(0);">(48,55)</a> Similarly, mAbs can oligomerize and exhibit mass heterogeneity from variable glycosylation, affecting pharmacokinetics, effector function, and stability. <a href="javascript:void(0);">(19)</a> CDMS may resolve and quantify such proteoforms in a single experiment without the need for charge reduction or chemical derivatization. <a href="javascript:void(0);">(48,56,57)</a>

Dissecting Heterogeneous Populations of Protein-Complex Samples Using Direct Mass Technology

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Organomation, founded in 1959, designs and manufactures high-quality nitrogen evaporators and extraction systems. Known for innovation and durability, their lab instruments are used globally for efficient sample preparation with strong customer support.

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ISTRAN EcaFlow Model 150 GLP automatic laboratory analyser

EcaFlow Model 150 GLP is a PC controlled automatic laboratory analyser for the determination of trace and high concentrations of metals, semi-metals and numerous nonmetals in various samples.

EcaFlow Model 150 GLP is a PC controlled automatic laboratory analyser for the determination of trace and high concentrations of metals, semi-metals and numerous nonmetals in various samples. By making use of the autosampler AS-150 up to 42 samples can be analysed in full automatic mode. The system supports the standardless, calibration curve and standard additions techniques. Over 70 validated applications are available for numerous sample types such as waters, foods, industrial liquids, wastes, etc. EcaFlow is a compact laboratory instrument controlled by a PC.<figure class="image"><img style="aspect-ratio:675/449;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_Eca_Flow_150_GLP_4_26c42795eb.jpg" alt="ISTRAN EcaFlow 150 GLP" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_Eca_Flow_150_GLP_4_26c42795eb.jpg 235w," sizes="100vw" width="675" height="449"></figure>The control unit contains the power support unit, control processor with a channel analyser, fast A/D and D/A converters and a high performance generic potentiostat/galvanostat. The compact flow system is controlled by the control unit and operates full automatically. It contains computer controlled electromagnetic valves for switching either to the sample solution or to an electrolyte solution or to a standard solution for the standard addition. Solutions are driven by a peristaltic pump. The heart of the system is the patented compact electrochemical cell.&nbsp;The cell uses disposable flow-through working electrodes made of suitable inert material. The counter and reference electrodes are separated from the flowing solutions hydrodynamically, so the reaction products at the counter electrode cannot interfere at the working electrode. The working electrode can be easily changed simply by loosening a screw. The cell is fixed to the panel of the instrument by a special connector which serves as an electrical contact to the electrodes. The connections of the tubes are made of Luer-type fitting, which facilitates fast manipulation when the electrode or cell is changed.<figure class="image"><img style="aspect-ratio:675/449;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_Eca_Flow_150_GLP_5_ac69cdfecf.jpg" alt="ISTRAN EcaFlow 150 GLP" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_Eca_Flow_150_GLP_5_ac69cdfecf.jpg 235w," sizes="100vw" width="675" height="449"></figure><h4>Technical data</h4>Potentiostat/galvanostat: 12 V / 20 mA Measuring cell: EcaCell 353c or EcaCell 104 with three electrodes Flow system: Full computer control with peristaltic pumping Weight: 7 kg Dimensions: 500 x 450 x 140 mm Software: Chronopotentiometry, coulometry, voltammetry Computer (option): Any PC with Windows XP and higher Autosampler (option): 42 positions + blank + standard<figure class="image"><img style="aspect-ratio:675/449;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_Eca_Flow_150_GLP_3_f4b61911c2.jpg" alt="ISTRAN EcaFlow 150 GLP" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_Eca_Flow_150_GLP_3_f4b61911c2.jpg 235w," sizes="100vw" width="675" height="449"></figure><h4>Available applications (all included):</h4><ol><li>Flow-through analyser test&nbsp;&nbsp;</li><li>Simultaneous determination of Cd, Pb and C&nbsp;</li><li>Determination of Pb&nbsp;</li><li>Simultaneous determination of Sn and Pb&nbsp;</li><li>Simultaneous determination of Pb, Cd and Hg&nbsp;</li><li>Determination of EDTA&nbsp;</li><li>Simultaneous determination of Zn, Cd, Pb, and Cu&nbsp;</li><li>Simultaneous determination of Cd, Pb, a Cu in wines&nbsp;</li><li>Determination of Ag&nbsp;</li><li>Determination of As(III) and total As in urine&nbsp;</li><li>Determination of As(III) and total As in fertilisers&nbsp;</li><li>Determination of Se in waters&nbsp;</li><li>Determination of Mn&nbsp;</li><li>Determination of Hg&nbsp;</li><li>Determination of Fe in waters&nbsp;</li><li>Determination of Sn&nbsp;</li><li>Determination of Bi&nbsp;</li><li>Determination of As in drugs&nbsp;</li><li>Determination of chlorides in waters&nbsp;</li><li>Simultaneous determination of Zn, Cd, Pb, and Cu in wines&nbsp;</li><li>Simultaneous determination of Zn, Cd, Pb, and Cu in spirits&nbsp;</li><li>Simultaneous determination of Cd, Pb, and Cu in beers&nbsp;</li><li>Determination of Fe (higher concentrations) in waters&nbsp;</li><li>Determination of Cd, Pb, and Cu in soil extracts&nbsp;</li><li>Determination of Sb&nbsp;</li><li>Simultaneous determination of Zn, Cd, Pb, and Cu in waters&nbsp;</li><li>Determination of As(III) and total As in waters&nbsp;</li><li>Determination of Zn, Cd, Pb, and Cu in pectines&nbsp;</li><li>Determination of iodides in urine&nbsp;</li><li>Determination of Au in water samples&nbsp;</li><li>Determination of low Ni contents&nbsp;</li><li>Determination of iodides in foods and beverages&nbsp;</li><li>Determination of Cr(VI) and total Cr in waters&nbsp;</li><li>Determination of nitrates in waters&nbsp;</li><li>Determination of Ascorbic Acid&nbsp;</li><li>Determination of chlorites in waters&nbsp;</li><li>Determination of bromates in waters&nbsp;</li><li>Boric acid in nickel plating baths&nbsp;</li><li>Determination of total As in waters&nbsp;</li><li>Acidimetry determination of strong and weak acids&nbsp;</li><li>Determination of Fe in concentrated sulphuric acid&nbsp;</li><li>Determination of Cu in waste waters&nbsp;</li><li>Alkalimetry determination of strong bases&nbsp;</li><li>Simultaneous determination of total As and Hg&nbsp;</li><li>Determination of Zn in galvanic baths&nbsp;</li><li>Determination of Ni in galvanic baths&nbsp;</li><li>Chlorides in galvanic baths&nbsp;</li><li>Cr(III) in passivating galvanic baths&nbsp;</li><li>Determination of phosphates with microporous electrodes&nbsp;</li><li>Determination of sub-ppb Hg concentrations&nbsp;</li><li>Determination of Zn in waste waters&nbsp;</li><li>Cu in wine samples&nbsp;</li><li>Determination of Fe in clear and turbid water samples&nbsp;</li><li>Determination of Au in ores&nbsp;</li><li>Determination of Sb in the presence of As and Cu&nbsp;</li><li>Determination of low Se concentrations&nbsp;</li><li>Sulphites in wines&nbsp;</li><li>Sulphites in beers&nbsp;</li><li>Titanium in TiO2&nbsp;</li><li>Determination of phosphates in clear as well as turbid water samples&nbsp;</li><li>Determination of total ammonia in underground and tap waters&nbsp;</li><li>Determination of total ammonia in waste waters&nbsp;</li><li>Determination of Cr(VI) in clear as well as turbid water samples&nbsp;</li><li>Determination of Ni in clear as well as turbid water samples&nbsp;</li><li>Determination of sulphides (S2-) in waste waters&nbsp;</li><li>Simultaneous determination of Zn, Cd, Pb, and Cu in turbid samples&nbsp;</li><li>Coulometric determination of sulphides in waters&nbsp;</li><li>Acid content in wines&nbsp;</li><li>Ethanol in beverages&nbsp;</li><li>Sulphites (SO3-) in foods&nbsp;</li><li>Chlorides (Cl-) in foods&nbsp;</li><li>Chlorites (ClO2-) in disinfected water&nbsp;</li><li>Manganese (Mn) in aquatic samples&nbsp;</li><li>Bromides (Br-) in water&nbsp;</li><li>Cd, Pb and Cu in concentrated zinc sulphate&nbsp;</li><li>Simultaneous determination of Pb, Cu and Hg in water</li></ol>

ISTRAN PCA2 Portable coulometric analyser

The new Portable Coulometric Analyser PCA is designed for laboratory and field analysis of heavy metals, semi-metals and numerous non-metals in aquatic solutions for a broad concentration range addressing contents from sub-μg/L up to several g/L.

The new Portable Coulometric Analyser PCA is designed for laboratory and field analysis of heavy metals, semi-metals and numerous non-metals in aquatic solutions for a broad concentration range addressing contents from sub-μg/L up to several g/L. In battery operation mode it is well suited for field applications. The analysis is full automatic, the sample solution is transported to the electrochemical measuring cell by means of a small but robust peristaltic pump and on completing the analysis the result is displayed and stored in the memory. The human interface is a simple touch screen.<h3>APPLICATION FIELDS</h3><ul><li>Drinking water</li><li>Surface water</li><li>Waste water</li><li>Foods and beverages</li><li>Biological samples</li></ul><figure class="image"><img style="aspect-ratio:1116/324;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_PCA_2_Portable_coulometric_analyser_aae89cc7dc.jpg" alt="ISTRAN PCA2 Portable coulometric analyser" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_PCA_2_Portable_coulometric_analyser_aae89cc7dc.jpg 245w," sizes="100vw" width="1116" height="324"></figure><h3>UNIQUE FEATURES</h3><ul><li>Metals, semi-metals, non-metals</li><li>Robust portable design</li><li>Full automatic analysis</li><li>At least 12 hours on battery operation ideal for field applications</li><li>Simple and fast operation</li><li>Ready to use applications</li><li>Broad concentration range, starting at sub-μg/L</li><li>Also suitable for coloured and turbid samples</li></ul><h3>TYPICAL APPLICATIONS INCLUDE</h3><ul><li>Arsenic, antimony, tin and selenium in various water samples</li><li>Heavy metals such as mercury, thallium, cadmium, indium, lead, bismuth, silver, gold.</li><li>Manganese, iron, cobalt, nickel, copper, zinc, gallium in various water samples</li><li>Chromium(VI) and total chromium</li><li>Iron(II), iron(III), total iron</li><li>Arsenic(III) and total arsenic</li><li>C-vitamin in vegetables, fruits, beverages, foods</li><li>Fluoride, chloride, bromide, iodide in waters and biological samples</li><li>Disinfection reagents such as chlorine, chlorine dioxide, hypochlorite in drinking water</li><li>Disinfection by-products such as chlorite, bromate in drinking water</li><li>Sulphite in foods, wines and beers</li><li>Sulphides in waste waters</li><li>Ammonia, hydrazine, nitrite, nitrate, cyanide in aquatic samples</li><li>Phosphate in waste waters</li><li>Ethanol in beverages</li><li>Methanol in waste water</li><li>Acids and bases in aquatic solutions, wines</li><li>Samples with suspended particles and solid samples can be analysed after an appropriate sample digestion, e.g. thermal, UV or microwave-assisted sample digestion.</li></ul>Ag, Ammonia, As, Bromate, Bromide, Cd, Chloride, Chlorite, Co, Cr(VI), Cu, EDTA, Fe, Hg, Iodide, Mn, Ni, Nitrite, Pb, Sb, Se, Sn, Sulphide, Tl, Zn<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Screenshot_2025_03_21_at_12_33_28_Istran_2_2d3350cbc8.jpg" alt="ISTRAN PCA2 Portable coulometric analyser" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Screenshot_2025_03_21_at_12_33_28_Istran_2_2d3350cbc8.jpg 245w," sizes="100vw" width="1116" height="326"><h3>ANALYSIS PRINCIPLE</h3>The analysis is based on automatic flow-through coulometry and voltammetry making use of a unique robust electrochemical measuring cell with a maintenance-free built-in reference and auxiliary electrodes and a long-life disposable working electrode. The sample solution is pumped into the cell where the determined species (analyte) is measured through its electrochemical conversion, i.e. it is electrochemically oxidised or reduced at the electrode surface. Low concentrations are determined after a preliminary electrochemical deposition of the measured species at the electrode surface (enrichment step), then the deposit is stripped by constant current while the signal is recorded and evaluated. In such a way, concentrations in the sub- μg/L level can be easily measured. A typical response of copper displayed on the touchscreen is depicted below.<figure class="image"><img style="aspect-ratio:1116/326;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_PCA_2_Portable_coulometric_analyser_3_d630e0cd53.jpg" alt="ISTRAN PCA2 Portable coulometric analyser: A typical response of copper displayed on the touchscreen" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_PCA_2_Portable_coulometric_analyser_3_d630e0cd53.jpg 245w," sizes="100vw" width="1116" height="326"></figure><h4>The analytical procedure consists of three main steps:</h4><ol><li>Sample preparation. It includes the filtration of the sample (when necessary) and addition of a reagent to the sample. Solid samples or samples with suspended particles require a sample digestion..</li><li>Analysis. Full automatic procedure yielding the result displayed on the touch screen. The analysis starts on immersing the sampling tube into the sample which is pumped through the measuring cell where the analyte is electrochemically measured. Usually multiple runs are done with measurements repeated and evaluated automatically.</li><li>Cleaning. On completion of the analyses the cell is rinsed with water or a suitable reagent solution and the analyser is set to standby mode or turned down.</li></ol><h3>CONTROL AND COMMUNICATION</h3><ul><li>User interface: Powerful 4.3” Intelligent LCD-TFT display module. 480 x 272 Resolution, RGB 65K true to life colours, TFT Screen with integrated 4-wire Resistive Touch Panel. On-board micro-SD memory card connector for data logging purposes</li><li>User interface for uploading new measuring parameters, downloading results and curves</li><li>User interface with administrator access, firmware upgrading and calibration of electronic circuits</li></ul><h3>MECHANICAL AND ELECTRICAL DATA</h3><ul><li>Enclosure: The PCA instrument is integrated into a robust transport case made of polypropylene. Watertight, crushproof, and dustproof. Protection class IP 67</li><li>Dimensions (W x D x H): 27 x 24.6 x 12.4 cm (10.62” x 9.68” x 4.87”)</li><li>Weight: 2.9 kg (6.4 lbs)</li><li>Power input: 100-240V/50-60Hz&nbsp;</li><li>Battery: Ni-MH, 14.4V/4.5Ah</li><li>Ambient operating conditions: 5 °C – 45 °C at 5 - 95% relative humidity non-condensing (41 °F – 113 °F)</li></ul><h3>TECHNICAL SPECIFICATIONS</h3><h4>MEASUREMENT</h4><ul><li>Analysis method: Coulometry and voltammetry in chronopotentiometric mode</li><li>Determined species: Metals, semi-metals, non-metals, organics (refer to the up to date list of applications)</li><li>Measuring cell: robust three-electrode flow-through cell. Built-in maintenance-free platinum auxiliary and silver/silver chloride reference electrodes. Longlife disposable working electrodes made of glassy carbon, gold, silver, platinum, copper. No mercury or gold plating solutions required.</li><li>Detection limit: less than 1 μg/L *</li><li>Precision (RSD, under repeatability conditions): 5 % full scale for calibration or validation solutions</li><li>Calibration: A built-in 10 point calibration curve adjusted in the factory</li><li>Re-calibration: Two point re-calibration (blank and calibration solution) carried out on demand</li><li>Measuring ranges: Please check the respective application list for each parameter</li><li>Analysis time/run: 1-10 min, depending on the analyte concentration *.</li></ul>*Refer to the corresponding application list<h4>DATA LOGGING AND SECURITY</h4><ul><li>Log files with over 1000 results and corresponding curves are stored</li><li>Easy export to spreadsheet files</li></ul><h4>GLP FEATURES</h4><ul><li>Automatic storage of about 1000 results, including the corresponding signal curve, date, time of analysis and the sample identifier.</li><li>Statistical evaluation of the results</li><li>Checking the accuracy and precision by means of a control sample with known analyte concentration.</li></ul><figure class="image"><img style="aspect-ratio:1116/326;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_PCA_2_Portable_coulometric_analyser_4_6b3bf1dde1.jpg" alt="ISTRAN PCA2 Portable coulometric analyser " srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_PCA_2_Portable_coulometric_analyser_4_6b3bf1dde1.jpg 245w," sizes="100vw" width="1116" height="326"></figure><h4>REAGENTS AND CONSUMABLES</h4><ul><li>Reagents, consumables, containers and tools can be transported in a separate transport case</li><li>Reagent consumption is low, usually 0.1 to 1 mL/sample</li><li>No organic or toxic reagents are used</li><li>All reagents and consumables are delivered by the producer</li><li>Reagent formulas are available against royalties</li><li>Cleaning solution: Demineralised water or in most cases tap water is sufficient</li><li>Calibration or validation solution: Available from the producer, prepared from single element Certified Reference Materials</li></ul><h4>OPTIONS</h4><ul><li>Additional applications each including a measurement parameter file, measuring cell (if needed), electrode</li><li>Transport case for reagents, consumables, tools ideal for field operation</li></ul>

ISTRAN EcaLayer Metal Layer Analyser

The coulometric method ensures accurate and precise results. The analyser is extremely simple to use and therefore it is also suitable for routine measurements not needing any special qualification.

The coulometric technique is used for measuring the thickness of electroplated deposits on a wide variety of substrates such as steel, aluminium, copper, nickel, silver, alloys, some insulators.The coulometric method ensures accurate and precise results. The analyser is extremely simple to use and therefore it is also suitable for routine measurements not needing any special qualification. Moreover, coulometry is the only method allowing the measurement of multi-layer coatings such as chrome, chrome oxide on tin, tin, tin-iron intermetals on steel, etc.<h3>Measuring principle</h3>The fundamental principle is the Faraday’s Law. The method is similar to the electrolytic plating process but here the coating is removed electrochemically from a defined surface area. For this purpose, a piece of the sample is placed to the flow-through measuring cell which is filled with a suitable electrolyte solution and the analysed metal coating is subsequently removed by applying an appropriate current. Hence, metal layers are measured by anodic dissolution, metal oxide layers, such as tin oxide on a tin coating, are measured by cathodic dissolution. The measured sample area is given by the gasket used and it can include 0.2 to 20 cm2. The analysis is performed totally automatically and is controlled by a PC.By applying the Faraday’s Laws, the thickness of a metal layer can be calculated.<h3>The EcaLayer Model 220/220a consists of three major parts:</h3><figure class="image"><img style="aspect-ratio:643/961;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_Eca_Layer_Metal_Layer_Analyser_4_ab4b7f6aff.jpg" alt="ISTRAN EcaLayer Metal Layer Analyser - Scheme" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_Eca_Layer_Metal_Layer_Analyser_4_ab4b7f6aff.jpg 104w," sizes="100vw" width="643" height="961"></figure><h4>1. Analytical Unit</h4><h5>Two types of analytical units can be used:</h5><ul><li>Module A for metal coatings and metal oxide layer measurements needing the removal of dissolved oxygen, e.g. tin oxide measurements, and</li><li>Module B for measurements not needing oxygen removal, e.g. tin layer thickness measurements.</li></ul>Module A encloses a unique flow-through analytical cell with the sample as the working electrode, a stainless steel counter and Ag/AgCl reference electrodes, a peristaltic pump, an electromagnetic valve for the gas and a reservoir for the electrolyte solution.Module B is built in the same way but without the gas unit.<h4>2. Control Unit</h4>The control unit comprises a computer controlled potentiostat/galvanostat with a maximum output of 100 mA, 16-bit A/D and D/A converters. The unit is controlled by a microprocessor linked to the PC through a serial line.<h4>3. Computer and software</h4>Any IBM compatible PC can be coupled to the instrument. The user-friendly software facilitates the use without any special knowledge about electrochermistry. GLP facilities such as archiving, printing of reports, selftesting are included.<h3>Function</h3><h4>The metal layer analyser works as follows:</h4><ol><li>The sample is placed into the cell and the cell is closed. The next steps are performed automatically by computer control.</li><li>The cell is filled with the electrolyte from the reservoir. If needed, the electrolyte solution is with an inert gas to remove dissolved oxygen.</li><li>The coating is removed by applying a suitable constant current and the potential of the sample material (i.e. the working electrode) is monitored and registered in the time.</li><li>The electrolyte solution is removed from the cell.</li><li>In the meantime, the registered potential-time dependence is evaluated giving the dissolution time and the layer thickness is calculated automatically.</li><li>The cell is opened and the sample is removed. The whole procedure takes 4 to 8 minutes.</li></ol><h3>Some applications</h3><h5>Measurements of tin coatings on steel</h5>Tin coatings are measured by anodic dissolution in HCl electrolyte solution with currents up to 100 mA. Both the tin and the tin-iron intermetallic layers can be measured in a single run.<figure class="image"><img style="aspect-ratio:621/342;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_Eca_Layer_Metal_Layer_Analyser_0d2f857bae.jpg" alt="ISTRAN EcaLayer Metal Layer Analyser: Measurements of tin coatings on steel" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_Eca_Layer_Metal_Layer_Analyser_0d2f857bae.jpg 245w," sizes="100vw" width="621" height="342"></figure><h5>Measurement of passivating chromous layers on tin coated steel</h5>The chromium layers are dissolved by anodic oxidation in a phosphate buffer electrolyte solution with currents of few mA.<figure class="image"><img style="aspect-ratio:645/353;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_Eca_Layer_Metal_Layer_Analyser_2_31bc2b54d5.jpg" alt="ISTRAN EcaLayer Metal Layer Analyser: Measurement of passivating chromous layers on tin coated steel" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_Eca_Layer_Metal_Layer_Analyser_2_31bc2b54d5.jpg 245w," sizes="100vw" width="645" height="353"></figure><h5>Measurement of oxide layers on tin coatings</h5>Oxide layers can be determined by cathodic dissolution in deairated HBr electrolyte solution with currents about -1 mA. Due to the uncertain stoichiometry of the oxide layers, the results are expressed as charge consumed per sample area.<figure class="image"><img style="aspect-ratio:685/348;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ISTRAN_Eca_Layer_Metal_Layer_Analyser_3_0b111ab468.jpg" alt="ISTRAN EcaLayer Metal Layer Analyser: Measurement of oxide layers on tin coatings" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ISTRAN_Eca_Layer_Metal_Layer_Analyser_3_0b111ab468.jpg 245w," sizes="100vw" width="685" height="348"></figure><h3>Ordering information</h3><h5>EcaLayer Model 220 includes</h5><ul><li>Control Unit</li><li>Flow System with Module A</li><li>Application software</li><li>PC with printer (specified by the customer)</li><li>All necessary cables</li><li>Users manual</li><li>Methodologies according to EN ISO 2177</li></ul><h5>EcaLayer Model 220a includes</h5><ul><li>Control Unit</li><li>Flow System with Module B</li><li>Application software</li><li>PC with printer (specified by the customer)</li><li>All necessary cables</li><li>Users manual</li><li>Methodologies according to EN ISO 2177</li></ul>

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