Meeting EU Drinking Water Standards: The Critical Role of Sample Prep in Trace Contaminant Analysis

<h3>Charged for Action: The Hidden Secrets of AEX Oligonucleotide Analysis</h3>Oligonucleotides—short, well-defined fragments of DNA or RNA—have become indispensable tools in modern life sciences. They underpin cutting-edge applications in molecular diagnostics, gene therapy, and pharmaceutical development. Before oligonucleotides can be confidently used in research or clinical settings, however, their quality must be rigorously assessed. Purity, sequence integrity, length distribution, and chemical modifications all play a decisive role in their performance.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Oligos_Made_Easy_Part_2_AEX_2_45eee54fa0.jpg" alt="KNAUER: Oligos Made Easy - Part 2: AEX" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Oligos_Made_Easy_Part_2_AEX_2_45eee54fa0.jpg 245w," sizes="100vw" width="1534" height="711">Among the analytical techniques available today, anion exchange chromatography (AEX) stands out as a robust and highly informative method for characterizing oligonucleotides. By exploiting their intrinsic negative charge, AEX provides detailed insight into product composition and impurity profiles that are difficult to obtain by other approaches.<blockquote><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/article/6808">Part 1 of the Oligos series: A Practical Guide to Oligonucleotide Production – From Concept to Final Product</a></blockquote><h4>How Scientists Read Oligonucleotides Using Charge</h4>At the core of AEX lies a simple but powerful principle: oligonucleotides carry a negatively charged phosphate backbone. This charge increases in a predictable way with strand length and, to a lesser extent, sequence composition. Anion exchange chromatography uses this property to separate oligonucleotides based on differences in charge strength and interaction with a positively charged stationary phase.As a result, AEX has become one of the most widely used analytical tools for evaluating oligonucleotide quality. It allows scientists to distinguish full-length products from truncated species, degradation products, or closely related variants—often with single-nucleotide resolution.<h4>Why Ion Exchange Works: Binding, Retention, and Release</h4>Ion exchange chromatography (IEX) relies on electrostatic interactions between analytes and a charged stationary phase. In the case of oligonucleotides, anion exchange is used, where negatively charged molecules interact with positively charged functional groups on the resin—most commonly quaternary amines.The system consists of two main components:<ul><li>Stationary phase: A positively charged resin that binds anionic analytes.</li><li>Mobile phase: An aqueous buffer system, typically combined with a salt gradient, that controls both pH and elution strength.</li></ul>Retention in AEX is governed primarily by charge. Molecules with weaker overall charge interact less strongly with the stationary phase and elute earlier, while more highly charged oligonucleotides bind more tightly and require stronger elution conditions.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Oligos_Made_Easy_Part_2_AEX_Figure_1_IEX_overview_including_elution_order_dependency_on_analyte_charge_3419ad3075.jpg" alt="KNAUER: Oligos Made Easy - Part 2 AEX: Figure 1 IEX overview including elution order dependency on analyte charge." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Oligos_Made_Easy_Part_2_AEX_Figure_1_IEX_overview_including_elution_order_dependency_on_analyte_charge_3419ad3075.jpg 245w," sizes="100vw" width="1583" height="654"><h4>The Five-Step Workflow of Ion Exchange Chromatography</h4>AEX separations generally follow a well-established sequence of steps:<ol><li>Column equilibration The column is conditioned with the starting buffer until the baseline and pH are stable. This ensures that all charged sites on the resin are ready for interaction.</li><li>Sample loading Samples, prepared in the starting buffer, are introduced under conditions that promote binding of the target oligonucleotides while minimizing retention of unwanted impurities.</li><li>Washing The column is washed with the starting buffer to remove uncharged or weakly interacting components. The baseline stabilizes as these species are flushed away.</li><li>Elution Bound oligonucleotides are released using a salt or pH gradient. Increasing ionic strength introduces competing ions that displace the analytes from the resin. Weakly bound species elute first; strongly charged oligonucleotides elute later.</li><li>Regeneration and re-equilibration A high-salt buffer removes any remaining bound material. The column is then returned to starting conditions in preparation for the next analysis.</li></ol><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Oligos_Made_Easy_Part_2_AEX_Figure_2_Five_steps_of_IEX_procedure_in_blue_outlined_using_an_example_chromatogram_in_red_38dd70b1b1.jpg" alt="KNAUER: Oligos Made Easy - Part 2 AEX: Figure 2 Five steps of IEX procedure (in blue), outlined using an example chromatogram (in red)." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Oligos_Made_Easy_Part_2_AEX_Figure_2_Five_steps_of_IEX_procedure_in_blue_outlined_using_an_example_chromatogram_in_red_38dd70b1b1.jpg 245w," sizes="100vw" width="1583" height="674"><h4>Why AEX Is Especially Effective for Oligonucleotides</h4>The repeating phosphate backbone of oligonucleotides gives rise to a strong and uniform anionic character across a wide pH range (typically pH 7–9). This makes oligonucleotides exceptionally well suited for anion exchange separations.Key factors influencing AEX behavior include:<ul><li>Charge density: Longer oligonucleotides carry more negative charges and therefore exhibit stronger retention.</li><li>Resin chemistry: Strong and weak anion exchangers differ in functional groups and pH stability, influencing selectivity and robustness.</li><li>Buffer composition: The choice of buffering ions and salt gradients directly affects elution strength and resolution.</li></ul>Salt gradients—commonly based on chloride ions—compete with the oligonucleotide backbone for binding sites on the resin. By carefully tuning gradient slope and composition, analysts can achieve highly reproducible and finely resolved separations.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Oligos_Made_Easy_Part_2_AEX_Figure_3_Ionic_interactions_and_p_H_influence_on_Anion_Exchange_Chromatography_AEX_612e231ba4.jpg" alt="KNAUER: Oligos Made Easy - Part 2 AEX: Figure 3 Ionic interactions and pH influence on Anion Exchange Chromatography (AEX)." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Oligos_Made_Easy_Part_2_AEX_Figure_3_Ionic_interactions_and_p_H_influence_on_Anion_Exchange_Chromatography_AEX_612e231ba4.jpg 245w," sizes="100vw" width="1547" height="593"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Oligos_Made_Easy_Part_2_AEX_Figure_4_AEX_buffer_selection_and_gradient_strategy_chromatogram_with_red_buffer_gradient_curve_53fd1bb11b.jpg" alt="KNAUER: Oligos Made Easy - Part 2 AEX: Figure 4 AEX buffer selection and gradient strategy (chromatogram with red buffer gradient curve)." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Oligos_Made_Easy_Part_2_AEX_Figure_4_AEX_buffer_selection_and_gradient_strategy_chromatogram_with_red_buffer_gradient_curve_53fd1bb11b.jpg 245w," sizes="100vw" width="1600" height="327"><h4>AEX as the Gold Standard for Oligonucleotide Separation</h4>Anion exchange chromatography has become the method of choice for both analytical and preparative oligonucleotide workflows. Its advantages include:<ul><li>High resolving power: Closely related impurities, including n–1 or n–2 species, can often be separated and quantified.</li><li>Predictable retention behavior: In many cases, retention time correlates linearly with oligonucleotide length, simplifying identification.</li><li>Compatibility with modified oligonucleotides: Even chemically modified sequences retain their anionic nature, allowing AEX to resolve both products and related impurities.</li><li>Excellent control via gradient elution: Salt gradients provide precise tuning of selectivity and resolution.</li></ul>Typically, shorter or degraded oligonucleotides elute at lower ionic strength, while full-length products with higher charge density appear later in the chromatogram.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Oligos_Made_Easy_Part_2_AEX_Figure_5_AEX_Advantages_and_Challenges_7835521e34.jpg" alt="KNAUER: Oligos Made Easy - Part 2 AEX: Figure 5 AEX Advantages and Challenges." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Oligos_Made_Easy_Part_2_AEX_Figure_5_AEX_Advantages_and_Challenges_7835521e34.jpg 245w," sizes="100vw" width="1535" height="707"><h4>Final Perspective: Mastering AEX with Confidence</h4>Anion exchange chromatography may appear complex at first, but with thoughtful optimization of pH, buffer composition, and gradient conditions, it becomes a highly precise and reliable tool for oligonucleotide analysis. When properly applied, AEX delivers sharp peaks, excellent resolution, and robust performance—even for challenging sequences and modifications.For laboratories developing or refining oligonucleotide workflows, AEX offers both analytical depth and operational confidence.<blockquote>If you would like to discuss AEX method development or optimization for oligonucleotides, feel free to contact us at sales@knauer.net. More insights into practical oligonucleotide analysis will follow in our “Oligos Made Easy” series.For technical questions or in-depth discussion, the author can be reached at kindler@knauer.net</blockquote>

Oligos Made Easy - Part 2: AEX

Although modern agriculture needs to be based on accurate real-time data on soil, plant, and environmental conditions, affordable, sufficiently sensitive, and robust monitoring devices for this purpose are currently missing. According to scientists, low-cost sensors based on new smart materials and printing technologies offer a suitable solution. The results of multidisciplinary research thus far and proposals for the development of these devices have been presented by researchers from Czechia, Great Britain, Spain, and the USA in a review article in the prestigious journal <a target="_blank" rel="noopener noreferrer" href="https://www.nature.com/articles/s41467-026-68778-6#Abs1">Nature Communications</a>.“Sensor technologies for monitoring plant health are still in their infancy. Only simple sensors capable of monitoring basic parameters such as pH, soil moisture, or temperature are commonly available on the market. However, if farmers are to face current challenges, including climate change, and ensure sufficient food for humanity, they need much more effective tools that will enable them to monitor, for example, various pathogens, including bacteria and fungi. In our opinion, a suitable solution is a combination of new smart materials and printing for the production of inexpensive, durable, and scalable materials,” said the article’s first author, David Panáček from CATRIN, who worked on the study during his internship at Imperial College London.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/CATRIN_Soucasne_senzory_nestaci_Vedci_navrhuji_novou_cestu_ke_sledovani_zdravi_rostlin_b4014952a3.jpg" alt="CATRIN: David Panáček" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_CATRIN_Soucasne_senzory_nestaci_Vedci_navrhuji_novou_cestu_ke_sledovani_zdravi_rostlin_b4014952a3.jpg 208w," sizes="100vw" width="1536" height="1152">Sensors for monitoring plant health, for example, lag behind similar devices used in human medicine. According to the authors, advances in materials science, which will enable the development of scalable sensor technologies, play a key role in this potential shift. “Printing techniques, including inkjet printing, screen printing, aerosol printing, 3D printing, and direct laser writing, offer flexible ways to produce flexible sensors, large-area sensors, and sensors integrated directly into plants. The review article summarizes recent advances in printable low-dimensional materials for agricultural sensors, analyzes their physico-chemical properties in relation to sensor performance, and discusses key challenges and future opportunities requiring interdisciplinary integration,” said one of the corresponding authors, Michal Otyepka.The research brought together materials scientists, chemists, biologists, sensing experts, and printing technology specialists. Materials research and the use of graphene-based smart materials were led by scientists from CATRIN at Palacký University and VŠB-Technical University of Ostrava. Plant biologists from CATRIN contributed their knowledge of plant development, their responses to stress conditions, and the monitoring of their properties. Researchers from Imperial College London took care of the electronics, while representatives from<a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/companies/36"> CEITEC – VUT</a> focused on printing technologies. The team also included leading experts in sensing from the Catalan Institute of Nanoscience and Nanotechnology in Barcelona, and Joseph Wang of the University of California San Diego, the “father of sensing and electrochemistry,” also contributed his extensive knowledge.“This is a groundbreaking study on this topic, which has managed to attract some truly big names in their respective fields. Last but not least, the study demonstrates that interdisciplinarity at CATRIN gives rise to completely new and promising research topics, such as plant sensing and its use for studying plant-environment interactions and smart agriculture,” added another corresponding author, Nuria De Diego.

Current sensors are not good enough. Scientists propose a new way to monitor plant health

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The Czech Advanced Technology and Research Institute (CATRIN) at Palacký University is a cutting-edge scientific hub dedicated to advancing research in the fields of nanotechnology, biotechnology, and biomedicine. At its core, CATRIN boasts outstanding scientific teams, featuring international researchers. We emphasize interdisciplinarity, foster global collaborations, and work to translate our research findings into practical applications.

CATRIN

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.

Organomation

Based in Berlin, KNAUER is a medium-sized, owner-managed company that has been serving the sciences since 1962. We develop and manufacture scientific instruments of superior quality for liquid chromatography, including: Analytical HPLC/UHPLC, Preparative HPLC, Fast protein liquid chromatography (FPLC), Multi-column chromatography/Simulated moving bed (SMB) chromatography. High pressure dosing, in-line detection systems, and osmometry are additional business areas.

KNAUER

Thermo Scientific Dionex IonPac AS22 Fast-4μm IC Columns

Attain the optimal combination of chromatographic speed and resolution using the Thermo Scientific™ Dionex™ IonPac™ AS22-Fast-4μm column.

Attain the optimal combination of chromatographic speed and resolution using the Thermo Scientific™ Dionex™ IonPac™ AS22-Fast-4μm column. Designed specifically for compliance monitoring of inorganic anions in accordance with U.S. EPA Method 300.0 (A), this moderate capacity column combines the selectivity of the Dionex IonPac AS22-Fast column with fast high resolution separations. Compared to the Dionex IonPac AS22-Fast column, the new Dionex IonPac AS22-Fast-4μm column uses smaller resin particles for more efficient separations resulting in faster run times, more accurate peak integration and more reliable results.<h5>Fast separation of common inorganic anions with excellent resolution</h5><ul><li>Obtain the highest peak efficiency, through the use of smaller resin particles, of common inorganic anions in diverse sample matrices</li><li>Attain fast isocratic separation of the common inorganic anions in less than 5 min</li><li>Perform compliance monitoring of common anions in drinking water as specified in U.S. EPA Method 300.0 (A)</li><li>Achieve excellent separation of inorganic anions and low-molecular weight acids in diverse sample matrices</li><li>Obtain high peak efficiency and increased peak resolution for more consistent integration and more reliable results</li><li>Transfer application easily--this 4μm column has the the same selectivity as the Dionex IonPac AS22-Fast column</li><li>Achieve excellent resolution of the carbonate peak away from the common inorganic anions</li><li>Reduce run time without loss of resolution compared to the Dionex IonPac AS22-Fast column</li><li>Faster alternative, using carbonate/bicarbonate eluents, for Dionex IonPac AS4A-SC, AS12A, AS14, AS14A and AS22 inorganic anion applications</li><li>Compatible with organic solvents to enhance analyte solubility, modify column selectivity, or allow effective column cleanup</li></ul><h5>Use with a high-pressure IC system</h5>Higher resolution is achieved through the use of smaller resin particles, which can produce a column backpressure over 3000 psi. When operating the Dionex IonPac AS22-Fast-4μm column, a high-pressure IC system, such as the <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/410">Thermo Scientific™ Dionex™ ICS-6000 HPIC</a> system is required.<h5>Use the format that fits your lab</h5><ul><li>4x150mm, 2x150mm analytical columns</li><li>4x30mm, 2x30mm guard columns</li><li>Shorter 150mm columns facilitate faster runs while the smaller particle size maintains a higher resolution separation</li></ul>Note: For simple, accurate eluent preparation, use the Dionex IonPac AS22 Eluent Concentrate or the Dionex Eluent Generator (Dionex EGC 500 K2CO3 cartridge with Dionex EPM 500 pH modifier).<h4>Specifications</h4><ul><li>Anion Exchange Capacity: 126 μeq</li><li>Crosslinking: 55% DVB</li><li>Column Capacity: 126 μeq</li><li>Column Chemistry: Carbonate/Bicarbonate</li><li>For Use With (Application): Anion Exchange</li><li>Ion Exchange Group: Alkanol Quaternary Ammonium Ion</li><li>Max. Pressure: 5000 psi (345 bar)</li><li>Solvent Compatibility: pH 0 to 14, 0 to 100% HPLC Solvents</li><li>Stationary phase: Super Macroporous Resin</li><li>Format: Standard Bore</li><li>Packing Material: Polymeric</li></ul>

Thermo Scientific Dionex IonPac AS19-4μm IC Columns

Achieve high resolution separations of trace oxyhalides and inorganic anions in drinking water using the Thermo Scientific™ Dionex™ IonPac™ AS19-4μm hydroxide-selective anion-exchange column.

Achieve high resolution separations of trace oxyhalides and inorganic anions in drinking water using the Thermo Scientific™ Dionex™ IonPac™ AS19-4μm hydroxide-selective anion-exchange column. Its high resolution, high capacity and selectivity allow the determination of bromate in drinking water at the low-μg/L level. Compared to the previous <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/2055">Dionex IonPac AS19 column</a>, this anion-exchange column uses smaller resin particles for more efficient separations resulting in more accurate peak integration and more reliable results.<h5>Easy Method Transfer</h5>With similar selectivity and increased peak efficiencies, you can easily transfer applications from the Dionex IonPac AS19 column to the Dionex IonPac AS19-4μm column.<h5>Significantly Reduce Eluent Usage</h5>The Dionex IonPac AS19-4μm Capillary Column is packed with the same material as the equivalent standard bore version (providing the same performance as a 4mm column), but requires only 1/100th the eluent flow rate. The capillary format provides the advantage of significantly reduced eluent consumption, which helps reduce operating costs.<h5>Dionex IonPac AS19-4μm Capillary Column Features</h5><ul><li>Choose from three formats: 4×250mm, 2×250mm and 0.4×250mm</li><li>Recommended hydroxide-selective column for trace bromate in drinking water matrices</li><li>Meets or exceeds performance requirements of US EPA Method 300.0 and US EPA Method 300.1</li><li>High capacity: 240μeq per column (4×250mm)</li><li>Column selectivity is optimized for 30 °C operating temperature</li><li>Compatible with organic solvents</li></ul>These capillary columns require high pressure Thermo Scientific™ Dionex™ ICS-5000+ or Dionex ICS-4000 HPIC™ system to run at standard flow rates.<h4>Specifications</h4><ul><li>Anion Exchange Capacity: 240 μeq</li><li>Crosslinking: 55% DVB</li><li>Column Capacity: 240 μeq</li><li>Column Chemistry: Hydroxide</li><li>For Use With (Application): Anion Exchange</li><li>Ion Exchange Group: Alkanol Quaternary Ammonium Ion</li><li>Max. Pressure: 5000 psi (345 bar)</li><li>Solvent Compatibility: pH 0 to 14, 0 to 100% HPLC Solvents</li><li>Stationary phase: IonPac AS19-4 μm</li><li>Format: Standard Bore</li><li>Packing Material: Polymeric</li></ul>

Thermo Scientific Dionex IonPac AS18-Fast IC Columns

Use these shorter 150mm Thermo Scientific™ Dionex™ IonPac™ AS18-Fast columns for fast runs when monitoring inorganic anions in drinking water and wastewater samples

Use these shorter 150mm Thermo Scientific™ Dionex™ IonPac™ AS18-Fast columns for fast runs when monitoring inorganic anions in drinking water and wastewater samples for compliance with U.S. EPA Methods 300.0 (A) and 300.1. Dionex IonPac AS18 columns are high capacity hydroxide-selective anion-exchange columns. Having the same selectivity as the <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/2054">Dionex IonPac AS18 column</a>, the shorter format significantly reduces run times of common inorganic anions and low molecular weight organic acids in diverse sample matrices including drinking water, wastewater, leachates, foods, beverages, and pharmaceutical preparations.<h5>Analysis of Common Inorganic Anions and Low-Molecular Weight Organic Acids in Diverse Matrices</h5><ul><li>Compliance monitoring of common anions in drinking water as specified in U.S. EPA Method 300.0 (A)</li><li>Determination of low levels of inorganic anions in complex matrices using large-loop injections</li><li>Superior retention and quantification of fluoride, acetate, and formate</li><li>Fast separation of the common inorganic anions in 5 min in simple matrices using 150mm column</li><li>High efficiency, fast analysis use the 150mm column for increased sample throughput</li><li>Compatible with organic solvents to enhance analyte solubility, modify column selectivity, or allow effective column cleanup</li></ul><h5>Recommended for Inorganic Anions in Diverse Sample Matrices</h5><ul><li>Source water and drinking water, municipal and industrial wastewater</li><li>Industrial cooling water and waste water, acid rain</li><li>Foods and beverages, anionic counterions in pharmaceutical preparations</li></ul><h5>Multiple Formats for Application Flexibility</h5>The shorter 150mm Dionex IonPac AS18-Fast columns produce faster runs of relatively clean matrices compared to the longer 250mm columns and are available in three formats with guard columns:<ul><li>4x150mm standard bore AS18-Fast columns with 4x30mm guard columns</li><li>2x150mm microbore AS18-Fast columns with 2x30mm guard columns</li><li>0.4x150mm capillary AS18-Fast columns with 0.4x35mm guard columns</li></ul><h5>Capillary Columns Reduce Operating Costs from Lower Eluent Requirements</h5>Capillary columns provide significantly reduced operating and waste disposal costs through eluent conservation. Packed with the same material, the Dionex IonPac AS18-Fast capillary columns provide the same performance as the standard bore and microbore counterparts. Operating costs are reduced because the capillary system operates at only 1% of the eluent flow rate of the standard bore system. Capillary columns are used with the Thermo Scientific™ Dionex™ ICS-4000 and ICS-5000+ Capillary systems.<h5>Need Higher Resolution or Faster Separations?</h5>If you need higher resolution separations of more complex sample matrices, refer to the longer 250mm Dionex™ IonPac™ AS18 Hydroxide-Selective Anion-Exchange column For fastest, highest resolution separations of relatively cleaner sample matrices, refer to the small particle Dionex™ IonPac™ AS18-4µm Hydroxide-Selective Anion-Exchange column. Use of 4µm columns requires a high-pressure IC system.<h4>Specifications</h4><ul><li>Anion Exchange Capacity: 171 μeq</li><li>Crosslinking: 55% DVB</li><li>Column Capacity: 171 μeq</li><li>Column Chemistry: Hydroxide</li><li>For Use With (Application): Anion Exchange</li><li>Ion Exchange Group: Alkanol Quaternary Ammonium Ion</li><li>Max. Pressure: 4000 psi (275 bar)</li><li>Solvent Compatibility: pH 0 to 14, 0 to 100% HPLC Solvents</li><li>Stationary phase: IonPac AS18-Fast</li><li>Format: Standard Bore</li><li>Packing Material: Ethylvinylbenzene/Divinylbenzene</li></ul>

Thermo Scientific Dionex IonPac AS18-Fast-4μm IC Columns

Attain the optimal combination of chromatographic speed and resolution using the new Thermo Scientific™ Dionex™ IonPac™ AS18-Fast-4μm anion-exchange column.

Attain the optimal combination of chromatographic speed and resolution using the new Thermo Scientific™ Dionex™ IonPac™ AS18-Fast-4μm anion-exchange column. This high-capacity, high-efficiency column provides excellent resolution of inorganic anions in diverse sample matrices. This is the hydroxide-selective column of choice for fastest compliance monitoring of inorganic anions in drinking water and wastewater samples in accordance with U.S. EPA Methods 300.0 (A) and 300.1. Compared to the Thermo Scientific™ Dionex™ IonPac™ AS18-Fast column, the new Dionex IonPac AS18-Fast-4μm anion-exchange column uses smaller resin particles for more efficient peaks resulting in faster run times, more accurate peak integration, and more reliable results.<h5>Fastest Separation of Common Inorganic Anions with Excellent Resolution</h5>Through the use of smaller resin particles and a shorter column format, this column offers the highest peak efficiency and best resolution of common inorganic anions for fast analysis of environmental waters.<h5>Analysis of Common Inorganic Anions and Low Molecular Weight Organic Acids in Diverse Matrices</h5><ul><li>Attain super fast isocratic separation of the common inorganic anions in less than 3 min</li><li>Compliance monitoring of common anions in drinking water as specified in U.S. EPA Method 300.0 (A)</li><li>High peak efficiency and increased peak resolution for more consistent integration and more reliable results</li><li>Offers the same selectivity as the Dionex IonPac AS18-Fast column so applications are easily transferred to the 4μm column</li><li>Reduces run time without loss of resolution compared to the Dionex IonPac AS18-Fast column</li><li>Achieve excellent separation of inorganic anions and low-molecular weight acids in diverse sample matrices</li><li>Compatible with organic solvents to enhance analyte solubility, modify column selectivity, or allow effective column cleanup</li></ul><h5>Use 4μm Columns with High-Pressure IC Systems</h5>Higher resolution is achieved through the use of smaller resin particles, which can produce a column backpressure over 3000 psi. When operating the Dionex IonPac AS18-Fast-4μm capillary column at the standard flow rate of 10μL/min, an IC system capable of operating up to 3000 psi is sufficient. However, to take advantage of the fast runs, using elevated flow rates, a high-pressure capillary IC system, such as the Thermo Scientific™ Dionex™ ICS-5000+ HPIC or the Thermo Scientific™ Dionex™ ICS-4000 HPIC is required. The Dionex ICS-5000+ HPIC system is required for standard operation of the Dionex IonPac AS18-Fast-4μm microbore and standard bore columns.<h5>Use the Format That Fits Your Lab</h5>Shorter 150mm AS18-Fast-4μm columns facilitate faster runs while the smaller particle size maintains a higher resolution separation and are available in 3 formats with guard columns:<ul><li>Use the 4x150mm standard bore column with the 4x30mm guard column</li><li>Use the 2x150mm analytical columns with the 2x30mm guard column</li><li>Use the 0.4x150mm capillary column with the 0.4x35mm guard column</li></ul><h5>Capillary Columns Reduce Operating Costs from Lower Eluent Requirements</h5>Capillary columns provide significantly reduced operating and waste disposal costs through eluent conservation. Packed with the same material, the Dionex IonPac AS18-Fast-4μm capillary columns provide the same performance as the standard bore and microbore counterparts. Operating costs are reduced because the capillary system operates at only 1% of the eluent flow rate of the standard bore system. Capillary columns are used with the Thermo Scientific™ Dionex™ ICS-4000 and ICS-5000+ Capillary systems.<h5>Need Higher Resolution or Faster Separations?</h5><ul><li>If you need higher resolution separations of more complex sample matrices, refer to the longer 250mm Dionex™ IonPac™ AS18 Hydroxide-Selective Anion-Exchange column</li><li>The shorter 150mm Dionex IonPac AS18-Fast columns produce faster runs of relatively clean matrices compared to the longer 250mm columns and operate under 3000 psi.</li></ul><h4>Specifications</h4><ul><li>Crosslinking: 55% DVB</li><li>Column Capacity: 174 μeq</li><li>For Use With (Application): Anion Exchange</li><li>Max. Pressure: 5000 psi (345 bar)</li><li>Solvent Compatibility: pH 0 to 14, 0 to 100% HPLC Solvents</li><li>Stationary phase: Super Macroporous Resin</li><li>Format: Standard Bore</li></ul>

Thermo Scientific Dionex IonPac AS16-4μm IC Columns

Determine trace levels of perchlorate and other highly polarizable anions in drinking water, surface water, and ground water with Thermo Scientific Dionex IonPac AS16-4μm IC Columns

<h5>Designed for simple, sensitive analysis</h5><ul><li>Easily measure trace concentrations of perchlorate in drinking water, surface water, and ground water matrices using a large-loop injection</li><li>Improved efficiencies and resolution compared to the standard <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/2052">Dionex IonPac AS16 column</a></li><li>Easily transfer applications from the Dionex IonPac AS16 column to the Dionex IonPac AS16-4μm column due to their similar selectivity</li><li>Ultralow hydrophobicity allows for fast analysis of highly polarizable anions (thiosulfate, iodide, thiocyanate, and perchlorate) with a simple, isocratic eluent</li><li>Ideal for polyvalent anions, including polyphosphates</li></ul><h5>Use with a high-pressure IC system</h5>Higher resolution is achieved through the use of smaller resin particles, which produce a column backpressure over 3000 psi at the standard flow rates. A high-pressure IC system, such as the Thermo Scientific™ Dionex™ ICS-5000+ HPIC™ system, Dionex Integrion™ HPIC system, or the Dionex ICS-4000 Integrated Capillary HPIC system is required to operate this column under standard conditions.<h5>Reduce operating costs with lower eluent requirements</h5>Capillary Dionex IonPac AS16-4μm columns provide the same performance as the standard bore and microbore Dionex IonPac AS16-4μm columns because they are packed with the same material. Operating costs are reduced because the capillary system operates at only 1% of the eluent flow rate of the standard bore system, requiring less eluent and producing less waste.<h5>Multiple Formats Available</h5><ul><li>4 x 250 mm and 2 x 250 mm analytical columns</li><li>4 x 50 mm and 2 x 50 mm analytical guard columns</li><li>0.4 x 250 mm capillary columns</li><li>0.4 x 50 mm capillary guard columns</li><li>Smaller i.d. columns provide higher mass sensitivity, eluent and reagent conservation, and lower operating costs</li></ul><h4>Specifications</h4><ul><li>Anion Exchange Capacity: 170 μeq</li><li>Crosslinking: 55% DVB</li><li>Column Capacity: 170 μeq</li><li>Column Chemistry: Hydroxide</li><li>For Use With (Application): Anion Exchange</li><li>Ion Exchange Group: Alkanol Quaternary Ammonium Ion</li><li>Max. Pressure: 5000 psi (345 bar)</li><li>Solvent Compatibility: pH 0 to 14, 0 to 100% HPLC Solvents</li><li>Stationary phase: Super Macroporous Resin</li><li>Format: Standard Bore</li><li>Packing Material: Ethylvinylbenzene/Divinylbenzene</li></ul>

Thermo Scientific Dionex IonPac AS11-HC-4μm IC Columns

Achieve the optimal combination of chromatographic speed and resolution in separating organic acids and inorganic anions in complex matrices using the new Thermo Scientific Dionex IonPac AS11-HC-4μm Column. 

Achieve the optimal combination of chromatographic speed and resolution in separating organic acids and inorganic anions in complex matrices using the new Thermo Scientific™ Dionex™ IonPac™ AS11-HC-4μm Capillary, Analytical &amp; Guard Column. This high-capacity, high-efficiency column provides excellent resolution of a large number of organic acids and inorganic anions in complex sample matrices. Compared to the Thermo Scientific™ Dionex™ IonPac™ AS11-HC column, this column uses smaller resin particles for more efficient separations resulting in more accurate peak integration and more reliable results.Complex sample matrices such as chemical wastewater effluents and fermentation broth solutions containing a variety of inorganic anions and organic acids can be analyzed using the high resolution Dionex IonPac AS11-HC-4μm column.&nbsp;Appropriate analytes include:<ul><li>Monovalent and divalent organic acids</li><li>Organic acids and inorganic anions in complex sample matrices or uncharacterized samples</li></ul><h5>Achieve Higher Resolution With High Capacity Columns</h5><ul><li>Facilitates injection of more concentrated samples without column overloading or peak broadening</li></ul><h5>Enjoy Higher Performance With the Smaller 4μm Resin Particle Size</h5><ul><li>Easily transfer applications from the Dionex IonPac AS11-HC column to the 4μm column</li><li>Get similar selectivity as the Dionex IonPac AS11-HC column</li><li>Increased peak resolution for more consistent results</li><li>Obtain improved separation for monovalent carboxylic acids, including quinate, lactate, acetate, propionate, formate, and butyrate</li></ul><h5>Use the Format That Fits Your Lab</h5>The Dionex IonPac AS11-HC-4μm column is available in three formats: 4x250 mm, 2x250 mm, and 0.4x250mm. The capillary format provides reduced eluent consumption, which helps reduce operating costs.<h5>Use With a High-Pressure Capillary IC System</h5>The smaller resin particles used in the Dionex IonPac AS11-HC-4μm column produces a backpressure over 3000 psi at the standard flow rates. A high-pressure capillary IC system, such as the Thermo Scientific™ Dionex™ ICS-5000+ HPIC™ or the Dionex ICS-4000 Capillary HPIC system is required to operate this column under standard conditions.<h5>For Best Performance</h5><ul><li>Use the Thermo Scientific™ Dionex™ IonPac™ AS11 column for fast analysis of organic acids and anions in well-characterized samples</li><li>Use the Thermo Scientific™ Dionex™ IonPac™ ICE-AS1 or ICE-AS6 columns for organic acids in high-ionic-strength samples</li></ul><h4>Specifications</h4><ul><li>Anion Exchange Capacity: 290 μeq</li><li>Column Capacity: 290 μeq</li><li>For Use With (Application): Anion Exchange</li><li>Max. Pressure: 5000 psi (345 bar)</li><li>Solvent Compatibility: pH 0 to 14, 0 to 100% HPLC Solvents</li><li>Stationary phase: IonPac AS11-HC-4μm</li><li>Format: Standard Bore</li></ul>

Thermo Scientific Dionex IonPac CS10 IC Columns

Choose Thermo Scientific Dionex IonPac CS10 Cation-Exchange Columns for isocratic separation of inorganic cations using hydrochloric acid (HCl) with diaminopropionic (DAP) acid eluents. 

Choose Thermo Scientific™ Dionex™ IonPac™ CS10 Cation-Exchange Columns for isocratic separation of inorganic cations using hydrochloric acid (HCl) with diaminopropionic (DAP) acid eluents. Well suited to determine common inorganic cations and aliphatic and aromatic amines in diverse sample matrices, including environmental waters, power plant waters treated with ammonium, morpholine, or ethanolamine; chemical additives; chemical process solutions; scrubber solutions; plating baths; and industrial solvents.<h5>Recommended Cation-Exchange Columns by Use</h5>Since the introduction of the Dionex IonPac CS10 column, Dionex has introduced several new cation-exchange columns with advanced features. These modern columns and their recommended uses are listed below.<ul><li>The Dionex IonPac CS11 column has selectivity similar to the Dionex IonPac CS10 column, with improved sensitivity and lower eluent consumption due to its smaller 2 mm i.d. format.</li><li>The Dionex IonPac CS12A column improves performance for fast analysis of inorganic cations and ammonium in diverse matrices.</li><li>The Dionex IonPac CS17 column is recommended for hydrophobic and polyvalent amines.</li><li>The Dionex IonPac CS19 and CS19-4μm columns are recommended for polar amines including alkanolamines and methylamines and also moderately hydrophobic amines and polyvalent amines.</li><li>Compatible with organic solvents, to enhance analyte solubility, modify column selectivity, or allow effective column cleanup</li></ul><h5>Formats Available for Application Flexibility</h5><ul><li>4x250mm analytical column</li><li>4x50mm guard column</li><li>Longer 250mm columns facilitate higher resolution separations of more complex sample matrices</li></ul><h4>Specifications</h4><ul><li>Column Capacity: 80 μeq</li><li>For Use With (Application): Cation Exchange</li><li>Max. Pressure: 4000 psi (275 bar)</li><li>Solvent Compatibility: pH 0 to 14, 0 to 100% HPLC Solvents</li><li>Stationary phase: IonPac CS10</li><li>Format: Standard Bore</li><li>Packing Material: Ethylvinylbenzene/Divinylbenzene</li></ul>

Thermo Scientific Dionex IonPac CS11 IC Columns

Choose Thermo Scientific Dionex IonPac CS11 low-capacity, sulfonate-functionalized, cation-exchange column for isocratic separation of inorganic cations using HCl with DAP eluents.

Choose Thermo Scientific™ Dionex™ IonPac™CS11 Analytical and Guard Columns for isocratic separation of inorganic cations using hydrochloric acid (HCl) with diaminopropionic (DAP) acid eluents. This column has selectivity similar to the IonPac CS10 column, with improved sensitivity and lower eluent consumption due to its smaller 2mm I.D. format.The Dionex IonPac CS11column can be used to determine common inorganic cations and aliphatic and aromatic amines in diverse sample matrices, however, advances in cation-exchange column technology have produced better column choices for these separations.<h5>Recommended Cation-Exchange Columns by Use</h5>Since the introduction of the Dionex IonPac CS11 column, Dionex has introduced several new cation-exchange columns with advanced features. For example, most modern Dionex IonPac Cation Exchange columns use simple methanesulfonic acid eluents rather than DAP-HCl eluents. These columns and their recommended uses are listed below.<ul><li>The Dionex IonPac CS12A column improves performance for fast analysis of inorganic cations and ammonium in diverse matrices.</li><li>The Dionex IonPac CS17 column is recommended for hydrophobic and polyvalent amines.</li><li>The Dionex IonPac CS19 and CS19-4μm columns are recommended for polar amines including alkanolamines and methylamines and also moderately hydrophobic amines and polyvalent amines.</li><li>Compatible with organic solvents, to enhance analyte solubility, modify column selectivity, or allow effective column cleanup</li></ul><h5>Formats Available for Application Flexibility</h5><ul><li>2x250mm analytical column</li><li>2x50mm guard column</li><li>Longer 250mm columns facilitate higher resolution separations of more complex sample matrices</li><li>Smaller i.d. columns provide higher mass sensitivity, eluent and reagent conservation and lower operating costs</li></ul><h4>Specifications</h4><ul><li>Crosslinking: 5% DVB</li><li>Column Capacity: 35 μeq</li><li>For Use With (Application): Cation Exchange</li><li>Max. Pressure: 4000 psi (275 bar)</li><li>Solvent Compatibility: pH 0 to 14, 0 to 100% HPLC Solvents</li><li>Stationary phase: IonPac CS11</li><li>Format: Microbore</li><li>Packing Material: Ethylvinylbenzene/Divinylbenzene</li></ul>

Thermo Scientific Dionex IonPac CS12 IC Columns

Obtain robust, reliable results and fast isocratic separation of common inorganic cations and alkanolamines using the Thermo Scientific Dionex IonPac CS12 Cation-Exchange Column.

Obtain robust, reliable results and fast isocratic separation of common inorganic cations and alkanolamines using the Thermo Scientific™ Dionex™ IonPac™ CS12 Cation-Exchange Column. This is a high-capacity, cation-exchange column designed for the fast, isocratic separation of lithium, sodium, ammonium, potassium, magnesium, and calcium using methanesulfonic or sulfuric acid eluents in diverse sample matrices. However, the newer Thermo Scientific™ Dionex™ IonPac™ CS12A column provides improved performance and is the recommended column for inorganic cation analysis.<h5>Fast Isocratic Separation of Common Inorganic Cations</h5>The Dionex IonPac CS12 Cation-Exchange Column provides fast, isocratic separation of cations in diverse sample matrices, including drinking water, power plant waters, soil extracts, acid digests, chemical additives, chemical process solutions, scrubber solutions, and plating baths. However, the Dionex IonPac CS12A column improves performance for fast analysis of inorganic cations and ammonium in diverse matrices and is the recommend column for these applications. The columns are compatible with organic solvents, excluding alcohols, to enhance analyte solubility, modify column selectivity, or allow effective column cleanup<h5>Multiple Formats Available for Application Flexibility</h5><ul><li>4x250mm, 2x250mm analytical columns</li><li>4x50mm, 2x50mm guard columns</li><li>Longer 250mm columns facilitate higher resolution separations of more complex sample matrices</li><li>Smaller i.d. columns provide higher mass sensitivity, eluent and reagent conservation and lower operating costs</li></ul><h4>Specifications</h4><ul><li>Crosslinking: 55% DVB</li><li>Column Capacity: 2.8 meq</li><li>For Use With (Application): Cation Exchange</li><li>Max. Pressure: 4000 psi (275 bar)</li><li>Solvent Compatibility: Acidic Eluents, 0 to 100% HPLC Solvent Compatible, Alcohols Should be Avoided</li><li>Stationary phase: Macroporous Resin</li><li>Format: Standard Bore</li><li>Packing Material: Ethylvinylbenzene/Divinylbenzene</li></ul>

Thermo Scientific Dionex IonPac CS12A IC Columns

Separate common cations in as little as four minutes using methanesulfonic acid (MSA) or sulfuric acid eluents with Thermo Scientific Dionex IonPac CS12A Cation-Exchange Columns.

Separate common cations in as little as four minutes using methanesulfonic acid (MSA) or sulfuric acid eluents with Thermo Scientific™ Dionex™ IonPac™ CS12A Cation-Exchange Columns. These medium-capacity, carboxylate-functionalized cation-exchange columns are recommended for fast, isocratic separation of lithium, sodium, ammonium, potassium, magnesium, and calcium in diverse sample matrices. The IonPac CS12A column is the recommended replacement for all IonPac CS12 column applications.<h5>Analysis of Common Cations plus Ammonium in Diverse Sample Matrices</h5><ul><li>Superior fast isocratic separation of mono- and divalent cations plus ammonium in diverse, complex matrices</li><li>Isocratic separation of Group I and II cations plus ammonium in 15 minutes in diverse matrices using a 250mm column</li><li>Fast, high resolution, isocratic separation of Group I and II cations plus ammonium in 4 minutes in simple matrices using 150mm column</li><li>Higher-capacity applications use 250mm columns, allowing injection of more concentrated samples without overloading or peak broadening</li><li>High efficiency, fast analysis use the 150mm column for increased sample throughput</li><li>Dionex IonPac CS12A-MS column provides fast elution at the low flow rates required for IC-MS, making it the ideal choice for IC-MS screening</li><li>Compatible with organic solvents, excluding alcohols, to enhance analyte solubility, modify column selectivity or allow effective column cleanup</li></ul>The Dionex IonPac CS12A-8μm and CS12A-5μm Capillary Columns offer the same selectivity as their analytical-scale counterparts with lowering operating costs.<h5>Recommended for Common Cations and Ammonium in Diverse Sample Matrices</h5><ul><li>Source water and drinking water, municipal and industrial wastewater, soil extracts, acid digests</li><li>Industrial cooling water, scrubber solutions; plating baths; and industrial solvents</li><li>Power plant waters treated with ammonium or morpholine; chemical additives; chemical process solutions</li></ul><h5>Reduce Operating Costs With Lower Eluent Requirements</h5>The Dionex IonPac CS12A capillary columns provide the same performance as the standard bore and microbore Dionex IonPac CS12A columns because they are packed with the same material. Operating costs are reduced because the capillary system operates at only 1% of the eluent flow rate of the standard bore system, requiring less eluent and producing less waste.<h5>Multiple Formats Available for Application Flexibility</h5><ul><li>4x250mm, 2x250mm, 3x150mm or 2x100mm analytical columns</li><li>4x50mm or 2x50mm, 3x30mm guard columns</li><li>0.4x250mm, 0.4x150mm capillary columns</li><li>0.4x50mm or 0.4x35mm capillary guard columns</li><li>Longer 250mm columns facilitate higher resolution separations of more complex sample matrices</li><li>Shorter 150mm and 100mm columns produce faster runs of relatively clean matrices</li><li>Smaller i.d. columns provide higher mass sensitivity, eluent and reagent conservation and lower operating costs</li></ul><h4>Specifications</h4><ul><li>Crosslinking: 55% DVB</li><li>Column Capacity: 2800 μeq</li><li>For Use With (Application): Cation Exchange</li><li>Max. Pressure: 4000 psi (275 bar)</li><li>Solvent Compatibility: Acidic Eluents, 0 to 100% Acetonitrile, Alcohols Should be Avoided</li><li>Stationary phase: IonPac CS12A-8μm</li><li>Format: Standard Bore</li><li>Packing Material: Ethylvinylbenzene/Divinylbenzene</li></ul>

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