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

<h3><strong>Charged for Action: The Hidden Secrets of AEX Oligonucleotide Analysis</strong></h3><p><strong>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.</strong></p><p><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"></p><p>Among the analytical techniques available today, <strong>anion exchange chromatography (AEX)</strong> 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.</p><blockquote><p><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/article/6808"><strong>Part 1 of the Oligos series: A Practical Guide to Oligonucleotide Production – From Concept to Final Product</strong></a></p></blockquote><h4><strong>How Scientists Read Oligonucleotides Using Charge</strong></h4><p>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.</p><p>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.</p><h4><strong>Why Ion Exchange Works: Binding, Retention, and Release</strong></h4><p>Ion exchange chromatography (IEX) relies on electrostatic interactions between analytes and a charged stationary phase. In the case of oligonucleotides, <strong>anion exchange</strong> is used, where negatively charged molecules interact with positively charged functional groups on the resin—most commonly quaternary amines.</p><p>The system consists of two main components:</p><ul><li><strong>Stationary phase:</strong> A positively charged resin that binds anionic analytes.</li><li><strong>Mobile phase:</strong> An aqueous buffer system, typically combined with a salt gradient, that controls both pH and elution strength.</li></ul><p>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.</p><p><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"></p><h4><strong>The Five-Step Workflow of Ion Exchange Chromatography</strong></h4><p>AEX separations generally follow a well-established sequence of steps:</p><ol><li><strong>Column equilibration</strong><br>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><strong>Sample loading</strong><br>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><strong>Washing</strong><br>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><strong>Elution</strong><br>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><strong>Regeneration and re-equilibration</strong><br>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><p><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"></p><h4><strong>Why AEX Is Especially Effective for Oligonucleotides</strong></h4><p>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.</p><p>Key factors influencing AEX behavior include:</p><ul><li><strong>Charge density:</strong> Longer oligonucleotides carry more negative charges and therefore exhibit stronger retention.</li><li><strong>Resin chemistry:</strong> Strong and weak anion exchangers differ in functional groups and pH stability, influencing selectivity and robustness.</li><li><strong>Buffer composition:</strong> The choice of buffering ions and salt gradients directly affects elution strength and resolution.</li></ul><p>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.</p><p><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"></p><p><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"></p><h4><strong>AEX as the Gold Standard for Oligonucleotide Separation</strong></h4><p>Anion exchange chromatography has become the method of choice for both analytical and preparative oligonucleotide workflows. Its advantages include:</p><ul><li><strong>High resolving power:</strong> Closely related impurities, including n–1 or n–2 species, can often be separated and quantified.</li><li><strong>Predictable retention behavior:</strong> In many cases, retention time correlates linearly with oligonucleotide length, simplifying identification.</li><li><strong>Compatibility with modified oligonucleotides:</strong> Even chemically modified sequences retain their anionic nature, allowing AEX to resolve both products and related impurities.</li><li><strong>Excellent control via gradient elution:</strong> Salt gradients provide precise tuning of selectivity and resolution.</li></ul><p>Typically, shorter or degraded oligonucleotides elute at lower ionic strength, while full-length products with higher charge density appear later in the chromatogram.</p><p><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"></p><h4><strong>Final Perspective: Mastering AEX with Confidence</strong></h4><p>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.</p><p>For laboratories developing or refining oligonucleotide workflows, AEX offers both analytical depth and operational confidence.</p><blockquote><p>If you would like to discuss AEX method development or optimization for oligonucleotides, feel free to contact us at <strong>sales@knauer.net</strong>. More insights into practical oligonucleotide analysis will follow in our <i>“Oligos Made Easy”</i> series.</p><p>For technical questions or in-depth discussion, the author can be reached at <strong>kindler@knauer.net</strong></p></blockquote>

Oligos Made Easy - Part 2: AEX

<p><strong>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 </strong><a target="_blank" rel="noopener noreferrer" href="https://www.nature.com/articles/s41467-026-68778-6#Abs1"><i><strong>Nature Communications</strong></i></a><strong>.</strong></p><p>“<i>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</i>,” said the article’s first author, <strong>David Panáček</strong> from CATRIN, who worked on the study during his internship at Imperial College London.</p><p><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"></p><p>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. “<i>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</i>,” said one of the corresponding authors, <strong>Michal Otyepka</strong>.</p><p>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"><strong> CEITEC – VUT</strong></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.</p><p>“<i>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,</i>” added another corresponding author, <strong>Nuria De Diego</strong>.</p>

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 CS14 IC Columns

Thermo Scientific Dionex IonPac CS14 IC is moderately low capacity cation-exchange column for analysis of aliphatic amines, aromatic amines, and polyamines using MSA or sulfuric acid eluents.

<p><strong>Obtain consistent reliable results for the analysis of aliphatic amines, aromatic amines, and polyamines using methanesulfonic acid (MSA) or sulfuric acid eluents with the Thermo Scientific™ Dionex™ IonPac™ CS14 Cation-Exchange Column. The column facilitates resolution of a large number of aliphatic amines and Group I and Group II cations in diverse sample matrices. However, the newer Thermo Scientific™ Dionex™ IonPac™ CS17, CS19 and CS19-4μm cation-exchange columns are recommended for these separations.</strong></p><p>Sample matrices can include environmental waters; power plant waters treated with ammonium, morpholine or ethanolamine; chemical additives; chemical process solutions; scrubber solutions; plating baths; industrial solvents; and wastewater.</p><h5><strong>Determination of Amines in Diverse Matrices</strong></h5><ul><li>Medium low-capacity carboxylate-functionalized hydrophilic cation-exchange column optimized for determination of a variety of amines</li><li>Dionex IonPac CS19 and CS17 columns are recommended replacement columns for most Dionex IonPac CS14 column applications</li><li>Dionex IonPac CS19 and CS19-4μm columns are recommended for polar amines, including alkanolamines and methylamines; and moderately hydrophobic and polyvalent amines, including biogenic amines and alkyldiamines</li><li>Compatible with organic solvents, (THF up to 20%), to enhance analyte solubility, modify column selectivity, or allow effective column cleanup</li></ul><h5><strong>Multiple Formats Available for Application Flexibility</strong></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><strong>Specifications</strong></h4><ul><li><strong>Crosslinking: </strong>55% DVB</li><li><strong>Column Capacity:</strong> 1300 μeq</li><li><strong>For Use With (Application):</strong> Cation Exchange</li><li><strong>Max. Pressure:</strong> 4000 psi (275 bar)</li><li><strong>Solvent Compatibility:</strong> Acidic Eluents, 0 to 100% HPLC Solvents, Except TFH 0 to 20% Compatible, Alcohols Should be Avoided</li><li><strong>Stationary phase:</strong> IonPac CS14</li><li><strong>Format:</strong> Standard Bore</li><li><strong>Packing Material: </strong>Ethylvinylbenzene/Divinylbenzene</li></ul>

Thermo Scientific Dionex IonPac CS15 IC Columns

Achieve accurate trace-level ethanolamine determination in high-ammonium matrices with the unique selectivity of the Dionex IonPac CS15 carboxylate-functionalized cation-exchange column.

<p><strong>Obtain consistent, reliable results for the determination of disparate concentration ratios of ethanolamine and ammonium in diverse sample matrices using the Thermo Scientific™ Dionex™ IonPac™ CS15 Cation-Exchange Column. This is a medium-capacity carboxylate-functionalized cation-exchange column with crown ether moiety. The column has unique selectivity, and is the only carboxylic acid based cation column from Dionex in which ethanolamines elute before ammonium. Thus, it is the column of choice for samples with high ammonium to low ethanolamine ratios.</strong></p><p>The Dionex IonPac CS15 column can also separate disparate ratios of sodium and ammonium, however, the advanced Thermo Scientific™ Dionex™ IonPac™ CS16 Cation Exchange column is recommended for this application.</p><h5><strong>Unique Selectivity for Ethanolamine and Ammonium in Complex Matrices</strong></h5><ul><li>Medium-capacity cation exchange column designed for the determination of trace levels of ethanolamine in high levels of ammonium in complex samples</li><li>Also ideal for the determination of trace-level sodium in amine-treated cooling waters with resolution of ammonium and sodium ratios up to 8,000:1</li><li>Determination of low level cations in matrices with high concentrations of potassium</li><li>Matrices include environmental waters; power plant waters treated with ammonium, morpholine or ethanolamine; chemical additives; chemical process solutions; scrubber solutions; plating baths; industrial solvents; and soil matrices</li><li>Maximum peak efficiencies at an optimized operating temperature of 40 ˚C</li><li>Compatible with organic solvents, excluding alcohols, to enhance analyte solubility, modify column selectivity, and facilitate effective column clean-up</li></ul><h5><strong>Multiple Formats Available for Application Flexibility</strong></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><strong>Specifications</strong></h4><ul><li><strong>Crosslinking: </strong>55% DVB</li><li><strong>Column Capacity:</strong> 2800 μeq</li><li><strong>For Use With (Application):</strong> Cation Exchange</li><li><strong>Max. Pressure:</strong> 4000 psi (275 bar)</li><li><strong>Solvent Compatibility:</strong> Acidic Eluents, 0 to 100% Acetonitrile, Alcohols Should be Avoided</li><li><strong>Stationary phase:</strong> IonPac CS15</li><li><strong>Format:</strong> Standard Bore</li><li><strong>Packing Material: </strong>Ethylvinylbenzene/Divinylbenzene</li></ul>

Thermo Scientific Dionex IonPac CS16 IC Columns

Resolve sodium and ammonium at ratios up to 20,000:1 with the IonPac CS16 column—ideal for complex matrices and adjacent cation analysis with high efficiency and low eluent use.

<p><strong>Determine disparate concentration ratios of adjacent eluting cations such as sodium and ammonium in diverse sample matrices using the Thermo Scientific™ Dionex™ IonPac™ CS16 Capillary, Analytical &amp; Guard Column. Sample matrices include environmental waters; power plant waters treated with ammonium, morpholine or ethanolamine; chemical additives; chemical process solutions; scrubber solutions; plating baths; and industrial solvents. The Dionex IonPac CS16 column is designed and recommended for use in most Thermo Scientific™ Dionex™ IonPac™ CS15 column applications due to its larger linear working range.</strong></p><h5><strong>Superior Performance When Determining Disparate Ratios of Sodium and Ammonium</strong></h5><ul><li>Optimized for the determination of disparate concentration ratios of adjacent eluting cations such as sodium and ammonium in diverse sample matrices.</li><li>Determination of short-chained alkylamines and alkanolamines in the presence of lithium, sodium, ammonium, potassium, magnesium, and calcium in complex sample matrices.</li><li>Resolution of sodium and ammonium ratios up to 10,000:1 in less than 20 minutes using an isocratic acid eluent</li><li>Resolution of sodium and ammonium ratios up to 20,000:1 using a gradient methanesulfonic acid (MSA) eluent</li><li>High capacity column for improved sample loadability and peak resolution</li><li>Maximum peak efficiencies at an optimized operating temperature of 40˚C</li><li>Best carboxylate-functionalized column for samples with low pH</li><li>Compatible with organic solvents, excluding alcohols, to enhance analyte solubility, modify column selectivity, and facilitate effective column clean-up</li></ul><h5><strong>Reduce Operating Costs With Lower Eluent Requirements</strong></h5><p>The Dionex IonPac CS16 capillary column provides the same performance as the standard bore and microbore Dionex IonPac CS16 columns because it is 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.</p><h5><strong>Multiple Formats Available for Application Flexibility</strong></h5><ul><li>5x250mm, 2x250mm analytical columns</li><li>5x50mm, 2x50mm guard columns</li><li>0.5x250mm capillary columnm, 0.5x50mm capillary 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><strong>Specifications</strong></h4><ul><li><strong>Crosslinking: </strong>55% DVB</li><li><strong>Column Capacity:</strong> 8400 μeq</li><li><strong>For Use With (Application):</strong> Cation Exchange</li><li><strong>Max. Pressure:</strong> 4000 psi (275 bar)</li><li><strong>Solvent Compatibility:</strong> Acidic Eluents, 0 to 100% HPLC Acetonitrile, Alcohols Should be Avoided</li><li><strong>Stationary phase:</strong> IonPac CS16</li><li><strong>Format:</strong> Standard Bore</li><li><strong>Packing Material: </strong>Ethylvinylbenzene/Divinylbenzene</li></ul>

Thermo Scientific Dionex IonPac CS16-4μm and CS16-Fast-4μm IC Columns

Resolve ammonium and sodium at ratios up to 10,000:1 with CS16-4μm columns. Faster, high-resolution cation analysis without pretreatment—even in complex matrices.

<p><strong>Analyze disparate concentration ratios up to 10,000:1 of close-eluting cations such as ammonium and sodium using Thermo Scientific™ Dionex™ IonPac™ CS16-4μm and CS16-Fast-4μm columns. Designed specifically for the analysis of cations at diverse concentration ratios, this high-capacity column combines the selectivity of the Dionex IonPac CS16 column with fast, high resolution separations. Compared to the Dionex IonPac CS16 column, the new Dionex IonPac CS16-4μm and CS16-Fast-4μm columns use smaller resin particles for more efficient separations resulting in faster run times, more accurate peak integration, and more reliable results.</strong></p><h5><strong>Highest Resolution Separation of Ammonium and Sodium at Disparate Concentration Ratios up to 10,000:1 in Diverse Matrices</strong></h5><ul><li>Recommended for trace-level ammonium in high concentrations of sodium without sample pretreatment</li><li>Recommended for trace-level sodium in high concentrations of ammonium without sample pretreatment</li><li>Use the 250 mm Dionex IonPac CS16-4μm for complex matrices</li><li>Use the 150 mm Dionex IonPac CS16-Fast-4μm for faster analyses in simple matrices.</li><li>Easily transfer applications from the Dionex IonPac CS16 column to the 4 μm columns due to the similar selectivity</li><li>High capacity facilitates injection of more concentrated samples without column overloading or peak broadening</li><li>Compatible with organic solvents, excluding alcohols, to enhance analyte solubility, modify column selectivity, and facilitate effective column clean-up</li></ul><h5><strong>Use with a High-Pressure IC System</strong></h5><p>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 <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/410"><strong>Thermo Scientific™ Dionex™ ICS-6000+ HPIC™ system</strong></a>, is required to operate this column under standard conditions and take advantage of elevated flow rates and faster run times.</p><h6><strong>Reduce Operating Costs With Lower Eluent Requirements</strong></h6><p>The Dionex IonPac CS16-4μm capillary columns provide the same performance as the standard bore and microbore Dionex IonPac CS16-4μm 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.</p><h5><strong>Multiple Formats Available for Application Flexibility</strong></h5><ul><li>Dionex IonPac CS16-4μm: Available in 4 mm, 2 mm, and 0.4 mm formats</li><li>Dionex IonPac CS16-Fast-4μm: Available in 4 mm and 2 mm formats</li><li>Longer 250 mm columns facilitate higher resolution separations of more complex sample matrices</li><li>Shorter 150 mm columns provide faster analyses of simple matrices</li><li>Smaller i.d. columns provide higher mass sensitivity, eluent and reagent conservation and lower operating costs</li></ul><h4><strong>Specifications</strong></h4><ul><li><strong>Crosslinking: </strong>55% DVB</li><li><strong>Column Capacity:</strong> 3220 μeq</li><li><strong>For Use With (Application):</strong> Cation Exchange</li><li><strong>Max. Pressure:</strong> 5000 psi (345 bar)</li><li><strong>Solvent Compatibility:</strong> Acidic Eluents (pH 0 to 7), 0 to 100% Acetonitrile, 0 to 100% Acetone, Alcohols Should be Avoided</li><li><strong>Stationary phase:</strong> IonPac CS16-4μm</li><li><strong>Format:</strong> Standard Bore</li><li><strong>Packing Material: </strong>Ethylvinylbenzene/Divinylbenzene</li></ul>

Thermo Scientific Dionex IonPac CS17 IC Columns

Obtain excellent selectivity and peak shapes for hydrophobic amines in complex matrices without solvent using the Thermo Scientific Dionex IonPac CS17 column.

<p><strong>Obtain excellent selectivity and peak shapes for hydrophobic amines in complex matrices without solvent using the Thermo Scientific™ Dionex™ IonPac™ CS17 column. This medium-capacity, carboxylate-functionalized column is optimized for the gradient separation of hydrophobic and polyvalent amines using simple aqueous eluents and elevated temperatures (40°C). It is intended for analysis of power plant waters treated with ammonium, morpholine, or ethanolamine; chemical additives; chemical process solutions; scrubber solutions; plating baths; industrial solvents; and food samples.</strong></p><h5><strong>Gradient Separation of Common Cations and Small Polar Amines in Diverse Matrices</strong></h5><ul><li>Hydrophilic, low-capacity column optimized for gradient separation of polyvalent and hydrophobic amines–including alkanolamines and methylamines–in complex sample matrices</li><li>Separation of moderately hydrophobic amines, including biogenic amines, alkyldiamines, and polyamines.</li><li>Minimal baseline shift and enhanced analyte sensitivity</li><li>Improved peak shape for most Thermo Scientific™ Dionex™ IonPac™ CS14, CS15, and CS16 column amine applications without the use of solvent</li><li>Optimized for simple acidic gradient applications</li><li>Compatibility with organic solvents to enhance analyte solubility, modify column selectivity, and facilitate effective column clean-up</li></ul><h5><strong>Multiple Formats Available for Application Flexibility</strong></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><strong>Specifications</strong></h4><ul><li><strong>Crosslinking: </strong>55% DVB</li><li><strong>Column Capacity:</strong> 1450 μeq</li><li><strong>For Use With (Application):</strong> Cation Exchange</li><li><strong>Max. Pressure:</strong> 4000 psi (275 bar)</li><li><strong>Solvent Compatibility:</strong> Acidic Eluents, 0 to 100% HPLC Solvents, Including Alcohols</li><li><strong>Stationary phase:</strong> IonPac CS17</li><li><strong>Format:</strong> Standard Bore</li><li><strong>Packing Material: </strong>Ethylvinylbenzene/Divinylbenzene</li></ul>

Thermo Scientific Dionex IonPac CS18 IC Columns

Separate polar amines with the Thermo Scientific™ Dionex™ IonPac™ CS18 Cation-Exchange Column. 

<p><strong>Separate polar amines with the Thermo Scientific™ Dionex™ IonPac™ CS18 Cation-Exchange Column. This low-capacity, carboxylate-functionalized column is specifically optimized for the separation of common cations, small polar amines, and moderately hydrophobic and polyvalent anions using simple aqueous eluents and elevated temperatures. However, the newer Thermo Scientific™ Dionex™ IonPac™ CS19 or Dionex IonPac CS19-4μm Cation Exchange Columns are the recommended columns for these applications.</strong></p><h5><strong>Cation and Amine Separations Using Suppressed and Non-suppressed Conductivity Detection</strong></h5><ul><li>Low-capacity column optimized for the isocratic and gradient separations of polar amines, moderately hydrophobic amines, and polyvalent cations</li><li>Can be used with suppressed and nonsuppressed conductivity detection</li><li>Nonsuppressed conductivity detection is recommended to extend calibration linearity for ammonium or weak bases</li><li>Can also be used for many of the nonsuppressed applications supported by the Dionex IonPac SCS-1 column but with much greater column stability</li><li>Optimized for simple acidic gradient separations with minimal baseline shift</li><li>Low capacity facilitates modest acid concentrations to elute polyvalent cations</li><li>Compatible with moderate amounts of organic solvents, excluding alcohols, to enhance analyte solubility, modify column selectivity, and facilitate effective column clean-up</li></ul><h5><strong>Formats Available for Application Flexibility</strong></h5><ul><li>2x250mm analytical columns</li><li>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><strong>Specifications</strong></h4><ul><li><strong>Crosslinking: </strong>55% DVB</li><li><strong>Column Capacity:</strong> 290 μeq</li><li><strong>For Use With (Application):</strong> Cation Exchange</li><li><strong>Max. Pressure:</strong> 4000 psi (275 bar)</li><li><strong>Solvent Compatibility:</strong> Acidic Eluents (pH 0 to 7), 0 to 20% HPLC Solvents, Alcohols Should be Avoided</li><li><strong>Stationary phase:</strong> IonPac CS18</li><li><strong>Format:</strong> Microbore</li><li><strong>Packing Material: </strong>Ethylvinylbenzene/Divinylbenzene</li></ul>

Thermo Scientific Dionex IonPac CS19 IC Columns

Separate common inorganic cations, small polar amines and polyvalent amines using Thermo Scientific Dionex IonPac CS19 IC Columns

<p><strong>Separate polar amines with the Thermo Scientific™ Dionex™ IonPac™ CS19 Cation-Exchange Column. This high-capacity, carboxylate-functionalized column is specifically optimized for the separation of common cations, small polar amines, and moderately hydrophobic and polyvalent cations using simple aqueous eluents and elevated temperatures. The column is ideal for analysis of power plant waters treated with ammonium, morpholine, or ethanolamine and can also be used to analyze chemical additives, chemical process solutions, scrubber solutions, personal care products, and food samples.</strong></p><h5><strong>Analyze Common Cations and Small Polar Amines in Diverse Matrices</strong></h5><ul><li>Simple gradient separation of small polar amines (including alkanolamines and methylamines), and moderately hydrophobic and polyvalent amines (including biogenic amines and alkyl diamines)</li><li>Optimized for simple acidic gradient separations with minimal baseline shift</li><li>High capacity facilitates the analysis of widely disparate peak pairs and high ionic strength matrices with less overloading of the column</li><li>Compatible with moderate amounts of organic solvents, excluding alcohols, to enhance analyte solubility, modify column selectivity, and facilitate effective column clean-up</li></ul><h5><strong>Multiple Formats Available for Application Flexibility</strong></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><strong>Specifications</strong></h4><ul><li><strong>Crosslinking: </strong>55% DVB</li><li><strong>Column Capacity:</strong> 2410 μeq</li><li><strong>For Use With (Application):</strong> Cation Exchange</li><li><strong>Max. Pressure:</strong> 3000 psi (207 bar)</li><li><strong>Solvent Compatibility:</strong> Acidic Eluents (pH 0 to 7), 0 to 10% HPLC Solvents, Alcohols Should be Avoided</li><li><strong>Stationary phase:</strong> Super Macroporous Resin</li><li><strong>Format:</strong> Standard Bore</li><li><strong>Packing Material: </strong>Ethylvinylbenzene/Divinylbenzene</li></ul>

Thermo Scientific Dionex IonPac CS19-4μm IC Columns

High-capacity ion-exchange column with 4 μm resin for highest resolution of cations and polar amines in complex samples. Enables fast, reliable separations and cost-effective operation with HPIC systems.

<p><strong>Attain the optimal combination of chromatographic speed and high resolution using the new Thermo Scientific™ Dionex™ IonPac™ CS19-4μm Capillary, Analytical, &amp; Guard Column. This high-capacity, high-resolution carboxylate-functionalized column provides excellent resolution of common cations, small polar amines, and polyvalent amines in complex sample matrices such as power plant waters treated with ammonium, morpholine, or ethanolamine, chemical additives, chemical process solutions, scrubber solutions, personal care products, and food samples.</strong><br><strong>Compared to the Thermo Scientific™ Dionex™ IonPac™ CS19 column, this column uses smaller resin particles for more efficient separations resulting in more accurate peak integration and more reliable results.</strong></p><h5><strong>Highest Resolution Separation of Common Cations and Small Polar Amines in Diverse Matrices</strong></h5><ul><li>Highest resolution, through the use of smaller resin particles, of common cations and small polar amines in complex sample matrices</li><li>Higher peak efficiency and increased peak resolution for more consistent integration and more reliable results</li><li>Easily transfer applications from the Dionex IonPac CS19 column to the 4 μm column due to the similar selectivity</li><li>Simple gradient separation of small polar amines (including alkanolamines and methylamines), and moderately hydrophobic and polyvalent amines (including biogenic amines and alkyl diamines)</li><li>High capacity facilitates injection of more concentrated samples without column overloading or peak broadening</li><li>Compatible with moderate amounts of organic solvents, excluding alcohols, to enhance analyte solubility, modify column selectivity, and facilitate effective column clean-up</li></ul><h5><strong>Use With a High-Pressure IC System</strong></h5><p>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™ or the Dionex ICS-4000 Capillary HPIC system is required to operate this column under standard conditions and take advantage of elevated flow rates and faster run times.</p><h5><strong>Reduce Operating Costs With Lower Eluent Requirements</strong></h5><p>The Dionex IonPac CS19-4μm capillary column provides the same performance as the standard bore and microbore Dionex IonPac CS19-4μm columns because it is 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.</p><h5><strong>Multiple Formats Available for Application Flexibility</strong></h5><ul><li>4x250mm, 2x250mm analytical columns</li><li>4x50mm, 2x50mm guard columns</li><li>0.4x250mm capillary column, 0.4x50mm capillary 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><strong>Specifications</strong></h4><ul><li><strong>Crosslinking: </strong>55% DVB</li><li><strong>Column Capacity:</strong> 2410 μeq</li><li><strong>For Use With (Application):</strong> Cation Exchange</li><li><strong>Max. Pressure:</strong> 5000 psi (345 bar)</li><li><strong>Solvent Compatibility:</strong> Acidic Eluents (pH 0 to 7), 10% HPLC Solvents, Alcohols Should be Avoided</li><li><strong>Stationary phase:</strong> IonPac CS19-4μm</li><li><strong>Format:</strong> Standard Bore</li></ul>

Thermo Scientific Dionex IonPac CS20 IC Columns

Analyze inorganic cations and amines using the Thermo Scientific™ Dionex™ IonPac™ CS20 ion chromatography (IC) columns.

<p><strong>Analyze inorganic cations and amines using the Thermo Scientific™ Dionex™ IonPac™ CS20 ion chromatography (IC) columns. Designed to complement Dionex IonPac CS18 and Dionex IonPac CS19 columns, the Dionex IonPac CS20 columns provide a large separation window between monovalent and divalent cations. This allows most amines to elute after the alkali metals but before the alkaline earth metals, moving the amines away from matrix ions that would normally make quantitation difficult. Its selectivity makes the Dionex IonPac CS20 particularly useful for determining a variety of alkyl and alkanol amines.</strong></p><h5><strong>Superior performance in the separation of common inorganic cations and amines</strong></h5><ul><li>Use the high capacity Dionex IonPac CS20 to determine inorganic cations and amines including methylamines, ethylamines, ethanolamines, and alkanolamines in diverse sample matrices</li><li>Unique stationary phase functionalized with a combination of sulfonic, phosphonic, and carboxylic acid groups can tolerate acidic samples containing up to 100mM hydronium ion (pH 1) with minimum loss of performance</li><li>Operable over a wide temperature range (15-70°C) to facilitate method development and improve critical pair separations</li><li>Compatible with 100% organic solvents (acetonitrile and acetone) to enhance analyte solubility, modify column selectivity, and facilitate effective column clean-up</li></ul><h5><strong>Use with a high-pressure IC system</strong></h5><p>A high-pressure IC system, such as the Thermo Scientific™ Dionex™ ICS-5000+ HPIC™, Dionex Integrion™ HPIC system, or the Dionex ICS-4000 Capillary HPIC system is required to operate this column under standard conditions.</p><h5><strong>Reduce operating costs with lower eluent requirements</strong></h5><p>The Dionex IonPac CS20 capillary columns provide the same performance as the standard bore and microbore Dionex IonPac CS20 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.</p><h5><strong>Multiple Formats Available</strong></h5><ul><li>4x250mm and 2x250mm analytical columns</li><li>4x50mm and 2x50mm analytical guard columns</li><li>0.4x250mm capillary columns</li><li>0.4x50mm capillary guard columns</li><li>Smaller i.d. columns provide higher mass sensitivity, conserve eluent and reagents, and reduce operating costs</li></ul><h4><strong>Specifications</strong></h4><ul><li><strong>Crosslinking: </strong>55% DVB</li><li><strong>Column Capacity:</strong> 3000 μeq</li><li><strong>For Use With (Application):</strong> Cation Exchange</li><li><strong>Max. Pressure:</strong> 5000 psi (345 bar)</li><li><strong>Solvent Compatibility:</strong> pH 0 to 7, 0 to 100% Organic HPLC Solvents, Alcohols Should be Avoided</li><li><strong>Stationary phase:</strong> Macroporous Resin</li><li><strong>Format:</strong> Standard Bore</li><li><strong>Packing Material: </strong>Ethylvinylbenzene/Divinylbenzene</li></ul>

Thermo Scientific Dionex IonPac CS21-Fast-4μm IC Columns

Resolve quaternary amine cationic polar pesticides including chlormequat, mepiquat, paraquat, and diquat with the Thermo Scientific™ Dionex™ IonPac™ CS21-Fast-4μm column. 

<p><strong>Resolve quaternary amine cationic polar pesticides including chlormequat, mepiquat, paraquat, and diquat with the Thermo Scientific™ Dionex™ IonPac™ CS21-Fast-4μm column. The unique selectivity of the Dionex IonPac CS21-Fast-4μm column allows it to resolve trace amounts of cationic polar pesticides in high ionic strength matrices within approximately fifteen minutes using an electrolytically generated MSA gradient. Quaternary amines are eluted away from matrix cations, making the Dionex IonPac CS21-Fast-4μm column ideal for IC-MS/MS applications where matrix ions are diverted to waste.</strong></p><h5><strong>Superior Chromatographic Performance</strong></h5><ul><li>High capacity allows injection of complex matrices without overloading the column while maintaining excellent peak shapes for lower concentration analytes.</li><li>Quickly separate trace levels of the four major quaternary amine cationic polar pesticides chlormequat, mepiquat, paraquat, and diquat in high ionic strength matrices using an MSA gradient.</li><li>Separate other cationic pesticides of interest including diethanolamine, triethanolamine, N-N-dimethylhydrazine, trimethylsulfonium, morpholine, melamine, streptomycin, and nereistoxin.</li></ul><h5><strong>Specifically designed for IC-MS/MS applications</strong></h5><ul><li>Completely resolves paraquat and diquat, species with similar masses.</li><li>Available in microbore format that is compatible with MS flow rates.</li><li>Selectivity allows matrix ions to be diverted to waste which keeps the MS source cleaner.</li><li>Solvent compatible (up to 100% acetonitrile and 20% isopropyl alcohol).</li><li>Fast analysis of cationic polar pesticides in food, beverages, and environmental waters.</li></ul><h5><strong>Use with a High-Pressure IC system</strong></h5><p>A high-pressure IC system, such as the <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/410"><strong>Thermo Scientific™ Dionex™ ICS-6000 HPIC system</strong></a> or <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/408"><strong>Thermo Scientific™ Dionex™ Integrion™ HPIC system</strong></a> is required to operate this column under standard conditions.</p><h4><strong>Specifications</strong></h4><ul><li><strong>Crosslinking: </strong>80% DVB</li><li><strong>Column Capacity:</strong> 110 μeq</li><li><strong>For Use With (Application):</strong> Cation Exchange</li><li><strong>Max. Pressure:</strong> 5000 psi (345 bar)</li><li><strong>Solvent Compatibility:</strong> pH 0-7, HPLC solvents (100% acetonitrile and up to 20% isopropyl alcohol), primary and secondary alcohols should be avoided)</li><li><strong>Format:</strong> Microbore</li><li><strong>Packing Material:</strong> Ethylvinylbenzene/Divinylbenzene</li></ul>

Products from category Ion Chromatography Columns (IC) - page 1

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