<p><strong>We are pleased to invite you to our upcoming free online webinar on June 11, 2026 focused on one of the most pressing challenges in environmental monitoring and water quality management — PFAS (Per- and Polyfluoroalkyl Substances).</strong></p><p>As regulatory frameworks continue to evolve and compliance deadlines approach, laboratories, water utilities, and environmental professionals need robust, reliable, and cutting-edge analytical solutions to stay ahead.</p><blockquote><p class="cke-user_style-important"><strong>👉</strong><a target="_blank" rel="noopener noreferrer" href="https://events.teams.microsoft.com/event/91d97003-fe33-4dca-b80b-160d9f8a5655@485ca04e-6f74-4050-9764-cdb4bfa89c25"><strong>Registration HERE</strong></a></p></blockquote><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ALS_analyzy_PFAS_a9e4a87fbc.jpg" alt="ALS: Advanced PFAS Analytical Services " srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ALS_analyzy_PFAS_a9e4a87fbc.jpg 245w," sizes="100vw" width="600" height="336"></p><h4><strong>🎤 Our Speaker</strong></h4><p>The webinar will be hosted by <strong>Jana Kováčová, Ph.D., PFAS Regional Lead for Continental Europe Environmental Division</strong>, who has dedicated the last several years to the field of PFAS analysis and determination in ALS laboratories. Jana is a recognized expert in PFAS environmental analytics and will share practical insights and the latest developments in analytical strategies to help your organization achieve and maintain compliance.</p><h4><strong>🎯 What You Will Learn</strong></h4><ul><li>Latest <strong>regulatory developments</strong> and compliance requirements for PFAS in water, including <strong>EU Drinking Water Directive 2020/2184</strong> and its implications for water suppliers and laboratories.</li><li><strong>Regulatory updates for surface water and groundwater</strong> — what's new and what to expect next.</li><li>Overview of <strong>advanced analytical strategies</strong> for PFAS detection and quantification in water matrices and how we analyse PFAS samples.</li><li>Key <strong>analytical challenges</strong> associated with PFAS testing — from ultra-trace detection to matrix interferences and contamination control.</li><li>The critical importance of using tested <strong>sampling containers</strong> and sample preservation to ensure reliable results.</li><li>Illustrative <strong>examples of results</strong> from real-world PFAS water analyses.</li><li>How ALS can support your needs with <strong>accredited PFAS testing services</strong>.</li></ul><h4><strong>👥 Who Should Attend</strong></h4><p>This webinar is designed for our clients, professionals, laboratory and technical staff, scientists, as well as anyone with an interest in analytical chemistry who wants to better understand the occurrence of these "forever chemicals" in the environment. &nbsp;</p><h4><strong>💬 Q&amp;A Session</strong></h4><p>There will be a live Q&amp;A session at the end of the webinar. You are welcome to submit your questions in advance during registration or ask them live on the day.</p><h4><strong>📅 Additional Webinar Info:</strong></h4><ul><li><strong>Platform: </strong>Microsoft Teams (online)</li><li><strong>Time: </strong>10:00 CEST</li><li><strong>Language: </strong>English</li><li><strong>Duration:</strong> approx. 45 - 60 minutes (incl. Q&amp;A)<br>Extras: If you are unable to attend on the day, please register and we will provide you with the recording of the webinar.</li></ul><h4><strong>🔬 About ALS Environmental</strong></h4><p>ALS is a global leader in environmental testing and analytical services, providing accredited PFAS analysis to clients across Europe and beyond. Our dedicated PFAS experts help clients navigate the complex regulatory landscape with confidence.</p><blockquote><p>For further information, please contact us on: <strong>marketing.cz@alsglobal.com</strong></p></blockquote><p>We look forward to welcoming you to this important discussion on PFAS compliance in water.</p>

Invitation to the ALS Webinar PFAS in Water 2026: Achieving Compliance through Advanced Analytical Strategies

News from LabRulezLCMS Library - Week 23, 2026

<p><strong>Solvent switching is the process of changing the solvent contained within a liquid chromatography (LC) column. This procedure must be performed carefully to avoid irreversible damage to the column.</strong></p><p>The topic originates from a common customer question:</p><blockquote><p>“My column arrived in hexane, but I need to use it with water and acetonitrile. How do I switch the solvents in the column?”</p></blockquote><p>This article explains the solvent switching process, how to determine the solvent currently inside a column, how to select an appropriate transition solvent, and why proper solvent switching is essential.</p><h2><strong>Step 1: Determine the Shipping Solvent</strong></h2><p>Before changing solvents, it is important to know which solvent or mobile phase is already present in the column.</p><p>This information can typically be found in:</p><ul><li>The column care guide</li><li>The Certificate of Quality Assurance (CQA)</li></ul><h4><strong>Using the Column Care Guide</strong></h4><p>The column care guide is usually available on the manufacturer's website under the specific column brand.</p><ul><li>In the <strong>Shipping Solvent</strong> section, users can identify the solvent in which each phase is supplied.</li><li>The <strong>Mobile Phase Compatibility</strong> section can be used to determine whether the phase has any mobile-phase limitations beyond pH restrictions.</li></ul><h4><strong>Using the Certificate of Quality Assurance (CQA)</strong></h4><p>The CQA also provides useful information.</p><p>Under the <strong>Test Conditions</strong> section, the mobile phases used to test the column are listed.</p><ul><li>In the example shown in the video, a Luna column was tested using:<ul><li>75% acetonitrile</li><li>25% water</li></ul></li></ul><p>The testing conditions are often the same as the shipping solvent conditions, although this is not always the case.</p><p>If uncertainty remains, the recommendation is to contact the column manufacturer directly.</p><h3><strong>Step 2: Check Solvent Miscibility</strong></h3><p>Once the shipping solvent is known, the next step is to verify whether it is miscible with the mobile phases used in the analytical method.</p><p>A solvent miscibility chart can be used for this purpose.</p><h4><strong>Water and Immiscible Solvents</strong></h4><p>The video highlights that water is immiscible with several commonly used LC solvents, including:</p><ul><li>Hexane</li><li>Dichloromethane (DCM)</li><li>Heptane</li></ul><p>These solvents are commonly used under normal-phase conditions.</p><h4><strong>Isopropanol as a Transition Solvent</strong></h4><p>The video identifies <strong>isopropanol (IPA)</strong> as a solvent that is miscible with all LC solvents shown in the chart.</p><p>Because of this property, IPA is commonly used as an intermediate or transition solvent when switching between:</p><ul><li>Water and hexane</li><li>Water and heptane</li></ul><h3><strong>Step 3: Perform the Solvent Switching Procedure</strong></h3><p>After selecting an appropriate transition solvent, the solvent exchange can begin.</p><p>The procedure described in the video consists of the following steps:</p><h4><strong>1. Flush with the Transition Solvent</strong></h4><p>Flush the column with the selected transition solvent for:</p><ul><li>30–60 column volumes</li></ul><h4><strong>2. Flush with the Pure Starting Solvent</strong></h4><p>After the transition solvent, flush the column with:</p><ul><li>10 column volumes of the pure starting solvent</li></ul><h4><strong>3. Equilibrate with the Method Mobile Phase</strong></h4><p>Finally, equilibrate the column using the mobile phases required for the analytical method.</p><h3><strong>Example Solvent Switching Protocol</strong></h3><p>The video provides the following example.</p><h5><strong>Initial Column Solvent</strong></h5><ul><li><strong>The column arrives packed in:</strong><ul><li>99% hexane</li><li>1% acetonitrile</li></ul></li></ul><h5><strong>Transition Solvent</strong></h5><ul><li><strong>Use:</strong><ul><li>Isopropanol (IPA)</li></ul></li><li><strong>Flush the column with IPA for:</strong><ul><li>30–60 column volumes</li></ul></li></ul><h5><strong>Intermediate Step</strong></h5><ul><li><strong>Flush with:</strong><ul><li>10 column volumes of acetonitrile</li></ul></li></ul><h5><strong>Final Equilibration</strong></h5><ul><li><strong>Equilibrate with one of the following:</strong><ul><li>50% acetonitrile / 50% water</li><li>50% acetonitrile / 50% buffered water</li></ul></li></ul><h3><strong>Why Proper Solvent Switching Is Important</strong></h3><p>The video emphasizes that improper solvent switching can cause irreversible column damage.</p><p>Potential issues include:</p><h4><strong>Formation of Voids and Pockets</strong></h4><p>Immiscible solvent transitions can create:</p><ul><li>Pockets within the packed bed</li><li>Voids at the column inlet</li></ul><p>These defects can permanently damage column performance.</p><h4><strong>Salt Precipitation</strong></h4><p>If buffered mobile phases are involved and pure solvents are not used appropriately during the transition, salts may precipitate from solution.</p><h4><strong>Damage to Pressure-Sensitive Polymer Media</strong></h4><p>Pressure-sensitive polymer-based media may burst during improper solvent transitions.</p><h4><strong>Stripping of Coated Phases</strong></h4><p>Columns containing coated stationary phases or coated ligands may experience removal of these coatings during unsuitable solvent changes.</p><h3><strong>Irreversibility of Column Damage</strong></h3><p>According to the video, once damage caused by immiscible solvent exposure occurs, it is extremely difficult—if not impossible—to reverse.</p><p>For this reason, solvent changes should always be performed through an appropriate intermediate solvent whenever required.</p><h3><strong>Conclusion</strong></h3><p>Successful solvent switching begins with identifying the solvent in which the column was shipped. The miscibility between the shipping solvent and the intended mobile phases must then be evaluated. When immiscible solvents are involved, an appropriate transition solvent such as isopropanol should be used.</p><p>Following a controlled sequence of flushing, intermediate solvent exchange, and equilibration helps prevent permanent column damage and ensures safe operation of the chromatographic column.</p>

Solvent Switching in Liquid Chromatography Columns: How to Change Column Solvents Safely

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