The quality of drinking water is under closer scrutiny than ever before. Beyond microbiological safety and major chemical contaminants, trace-level organic compounds increasingly determine whether water is perceived as clean, safe, and acceptable by consumers. Among these substances, volatile organic compounds (VOCs) play a central role — both from a regulatory and a sensory perspective.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Thermo_Fisher_Scientific_VOC_Analysis_in_Drinking_Water_Achieving_ppt_Level_Sensitivity_with_ITEX_Dynamic_Headspace_GC_MS_b4de2f994a.jpg" alt="Thermo Fisher Scientific: VOC Analysis in Drinking Water: Achieving ppt-Level Sensitivity with ITEX Dynamic Headspace GC-MS" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Thermo_Fisher_Scientific_VOC_Analysis_in_Drinking_Water_Achieving_ppt_Level_Sensitivity_with_ITEX_Dynamic_Headspace_GC_MS_b4de2f994a.jpg 245w," sizes="100vw" width="1024" height="512">Modern analytical laboratories face a dual challenge: complying with stringent legal requirements while simultaneously detecting compounds that are noticeable by humans at concentrations far below established health-based limits. This is particularly true for odor-active VOCs, where customer complaints may arise even when water is fully compliant.<h3>What are VOCs — and why are they so challenging?</h3>VOCs are a heterogeneous group of compounds defined primarily by their physical properties rather than their chemical structure. They typically exhibit:<ul><li>Low molecular weight</li><li>Relatively low boiling points (approximately 50–260 °C)</li><li>High vapor pressure</li><li>Low to moderate solubility in water</li></ul>This group includes substances such as light halogenated hydrocarbons (LHKW), aromatic hydrocarbons (BTEX), and trihalomethanes (THMs), many of which are regulated in drinking water due to toxicological concerns or their role as disinfection by-products from an analytical standpoint, these same properties make VOCs difficult to quantify at ultra-trace levels. Losses during sample handling, insufficient enrichment, and water interference can all limit sensitivity — especially when target concentrations are in the low µg/L or ng/L range.<h3>Regulatory pressure drives method sensitivity</h3>European drinking water legislation defines not only maximum allowable concentrations but also strict performance criteria for analytical methods. <a target="_blank" rel="noopener noreferrer" href="https://eur-lex.europa.eu/eli/dir/2009/90/oj/eng?utm_source=chatgpt.com">Directive 2009/90/EC</a> requires limits of quantification to be no higher than 30% of the applicable environmental quality standard. For many VOCs, this translates directly into ppt-level analytical requirements.As a result, laboratories must rely on techniques that go beyond conventional workflows while still maintaining robustness, reproducibility, and ease of use.<h3>Headspace GC-MS: established — but not always sufficient</h3>Headspace GC-MS remains a cornerstone of VOC analysis in water. <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/64">Static headspace</a> (SHS) methods are widely used due to their simplicity, cleanliness, and compatibility with routine laboratories. However, SHS relies on a single equilibrium extraction of the gas phase, which can limit sensitivity — particularly for very volatile compounds or analytes present at trace concentrations.For these applications, additional enrichment steps are often required.<h3>ITEX dynamic headspace: turning sampling into enrichment</h3><a target="_blank" rel="noopener noreferrer" href="https://www.thermofisher.com/order/catalog/product/1R77010-1125">ITEX (In-Tube Extraction) Dynamic Headspace</a> bridges the gap between simplicity and sensitivity. Unlike static headspace, ITEX repeatedly draws defined volumes of headspace gas through an adsorbent trap, actively enriching analytes before injection into the GC system.This dynamic approach offers several decisive advantages:<ul><li>True analyte enrichment directly from the headspace</li><li>Solvent-free sample preparation</li><li>Reduced risk of contamination and carryover due to a closed, syringe-based design</li><li>Straightforward maintenance with easy access to trap and syringe components</li></ul>By passing the headspace through the trap multiple times, ITEX effectively increases the sampled analyte mass without increasing sample volume — a key advantage for ppt-level analysis.<h3>Tailored adsorbents for targeted performance</h3>ITEX performance can be optimized through the selection of appropriate adsorbent materials:<ul><li>Tenax TA for volatile and semi-volatile compounds</li><li>Carbopack for hydrophobic analytes with minimized water displacement</li><li>Carboxen and Carbosieve materials for very volatile compounds such as vinyl chloride</li></ul>This flexibility allows laboratories to adapt ITEX methods to a wide range of drinking water applications, from regulatory VOC panels to specialized odor investigations.<h3>Managing water — without compromising sensitivity</h3>Water is often the hidden enemy of trace VOC analysis. In ITEX, excess water can be efficiently removed by purging the trap with inert gas at low temperature before thermal desorption. The trap itself can then be heated to temperatures of up to 350 °C, ensuring complete desorption of analytes while maintaining excellent repeatability.Carryover testing demonstrated values of ≤0.027% for all analytes, even without blank subtraction — a critical requirement for trace analysis in regulated environments.<h3>Chromatographic focusing for very volatile compounds</h3>Highly volatile VOCs remain chromatographically challenging, even after enrichment. Combining ITEX with <a target="_blank" rel="noopener noreferrer" href="https://www.thermofisher.com/content/lifetech/global/en/home/industrial/chromatography/gas-chromatography-gc/gc-systems/modules.html">PTV injection</a> and dedicated focusing liners significantly improves peak shape and signal-to-noise ratio. This double-focusing approach is especially effective for compounds such as vinyl chloride and other light halogenated hydrocarbons. When paired with SIM acquisition in <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/484">GC-MS</a>, the result is robust, sensitive, and selective detection across a broad VOC range.<h3>Taste and odor: why ppt really matters</h3>One of the most demanding applications in drinking water analysis is the detection of odor-active compounds such as geosmin. Produced naturally by cyanobacteria and actinomycetes, geosmin causes an earthy, musty taste and odor that consumers can detect at concentrations as low as 5–10 ng/L.Although geosmin poses no health risk, even trace levels can trigger complaints and damage public trust. ITEX Dynamic Headspace GC-MS enables reliable detection well below the sensory threshold, supporting proactive water quality management rather than reactive troubleshooting.<h3>Automation and flexibility for the modern laboratory</h3>Drinking water laboratories often analyze a wide range of sample types and concentration levels. Automated platforms such as the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/422">TriPlus RSH SMART</a> autosampler support multiple injection and sampling techniques — including liquid injection, static headspace, SPME, and ITEX — with automatic tool change functionality.Intelligent sequence control and consumable monitoring help laboratories maximize productivity while maintaining consistent analytical performance.<h3>Conclusion: a future-proof approach to VOC analysis</h3>ITEX Dynamic Headspace has proven to be a powerful and versatile alternative to purge-and-trap for the analysis of VOCs in drinking water. Its ability to deliver ppt-level sensitivity, combined with operational simplicity and excellent robustness, makes it ideally suited for both regulatory compliance and advanced odor analysis.When integrated with PTV injection and SIM-based GC-MS detection, ITEX-DHS supports reliable quantification of even the most challenging VOCs — helping laboratories meet today’s requirements while preparing for tomorrow’s expectationsCall to action:To learn more about this interesting technology in a FREE webinar, register here:<ul><li><a target="_blank" rel="noopener noreferrer" href="https://event.on24.com/wcc/r/5250532/C85F8F6AC85928EE5DB65E38D3C9B23F">April 23-Trinkwasserübewachung mit der ITEX</a></li><li><a target="_blank" rel="noopener noreferrer" href="https://event.on24.com/wcc/r/5250534/258DDD452DE6AAA5FDEB0E72CBF70889">June 11th VOC Analytik in Trinkwasser mittels Headspace GC-MS und ITEX</a></li></ul><h3>Acknowledgement</h3>I would like to thank Dr. Klaus Schrickel, Thermo Fisher Scientific Dreieich, Germany, for the contribution to this blog.<ul><li>Visit us on&nbsp;<a target="_blank" rel="noopener noreferrer" href="https://www.linkedin.com/showcase/72003132/admin/dashboard/">LinkedIn:</a>&nbsp;#GC #GC/MS # ITEX #Headspace</li></ul><blockquote><h5>Petra Gerhards</h5>Petra Gerhards, Dipl-Ing, is Regional Marketing Manager of GC and GC-MS for EMEA at Thermo Fisher Scientific. She has more than 29 years of experience in the fields of GC-MS, SPE and LC-MS. Since joining the regional team she has contributed to workflow solutions combining vials and closures with SPE solutions, GC-MS and LC-MS. She works with KOL's on data for regional specific marketing campaigns, organizes in-house seminars and works on customer specific solutions. Her main expertise is in the field of doping and drugs-of-abuse analysis.</blockquote>

VOC Analysis in Drinking Water: Achieving ppt-Level Sensitivity with ITEX Dynamic Headspace GC-MS

<h4>The problem&nbsp;</h4>We live in a “global village” but we are all different and we use many different languages to communicate.&nbsp;Even when people speak the same language, the same words may be used with different meanings. See, for example, some different uses of the word “standard” in English – a normative document, a solution of known concentration or even a type of flag.&nbsp;Even in the same area of activity misunderstandings do occur which may result in a waste of time and money, or even worse consequences.&nbsp;When talking about laboratory tests, lack of a full understanding of key terms and inappropriate translations leaves room for different interpretations of stated requirements. For example, there have historically been a number of different but related uses of the term ‘detection limit’. This may lead to inadequate fulfilment of those requirements, thus becoming an obstacle to the production of analytical data that is fit for its intended use. A shared interpretation of concepts related to quality in measurement between laboratories and accreditation bodies is also crucial for a fair and harmonised approach to laboratory assessment across the world.&nbsp;<h4>A common language&nbsp;</h4>We need a common language; clear and unambiguous. We need a common vocabulary to provide consistent definitions of concepts with their associated terms. To this end, several organisations participate in a joint effort to develop and maintain an international vocabulary of metrology (VIM) [1], which aims to achieve a unique understanding of concepts related to measurements across all sectors. The VIM is a normative reference in the standards ISO/IEC 17025, ISO 15189 and ISO/IEC 17043, and is therefore a key document for all organisations seeking accreditation.&nbsp;<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Eurachem_You_talk_we_understand_The_way_out_of_the_tower_of_Babel_Standards_8d947dbd5f.jpg" alt="Eurachem: You talk, we understand – The way out of the tower of Babel_A common language" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Eurachem_You_talk_we_understand_The_way_out_of_the_tower_of_Babel_Standards_8d947dbd5f.jpg 245w," sizes="100vw" width="1126" height="499"><h4>Is this enough?&nbsp;</h4>For laboratory staff some problems still stand and need to be addressed:&nbsp;<ul><li>Many people are confused about both concepts and terms.&nbsp;</li><li>It may be difficult to understand the “formal” VIM definitions – they are short statements intended to apply to many different measurement sectors.</li><li>Translations into local languages may add to the confusion, e.g. if different terms are used in different sectors for the same VIM concept and the translator overlooks this issue.</li><li>Some substantial changes to terminology have been made in an attempt to accommodate chemical and biological measurements. Some “old” concepts still stand but have new names, e.g. “within laboratory reproducibility” vs. “intermediate precision”.&nbsp;</li></ul>To address these issues Eurachem has produced a guide [2] which provides an accessible reference containing simple and in context explanations of terms most relevant to analysts, with additional examples relating those concepts to chemical and biological measurements.&nbsp;<h4>Do you understand the meaning of these terms?&nbsp;</h4>Are you interested in a quantity or a quality? Depending on the answer, will you use a measurement procedure or an examination? Is method verification the same or less demanding than method validation? Do you need a calibration or just performance verification? Do you have a measurement standard in your laboratory? Is metrological traceability something you worry about? These are examples of the terms supporting the reliability of any measurement result that need to be clearly understood.&nbsp;<h5>Example – Accuracy, trueness, precision: are they synonyms?&nbsp;</h5><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Eurachem_You_talk_we_understand_The_way_out_of_the_tower_of_Babel_accuracy_231e1e005e.jpg" alt="Eurachem: You talk, we understand – The way out of the tower of Babel_Example – Accuracy, trueness, precision" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Eurachem_You_talk_we_understand_The_way_out_of_the_tower_of_Babel_accuracy_231e1e005e.jpg 146w," sizes="100vw" width="754" height="807"><ul><li>Closeness between measurement results (relating to the concept of precision)</li><li>Closeness of the average of the measurement results to a reference value (relating to the concept of trueness)&nbsp;</li><li>Closeness of an individual measurement result to the true value (relating to the concept of accuracy)&nbsp;</li></ul>The different situations in the figure show the effect of:&nbsp;<ol style="list-style-type:lower-latin;"><li>poor precision and trueness (imprecise and biased)&nbsp;</li><li>good precision, poor trueness (precise but biased)&nbsp;</li><li>poor precision, good trueness (imprecise but unbiased)&nbsp;</li><li>good precision and trueness (precise and unbiased)&nbsp;</li></ol>Improving both precision and trueness is expected to improve accuracy.&nbsp;<h4>Is all this relevant to you?&nbsp;</h4>Do you work in a laboratory, either as an analyst, quality manager or director? Are you involved in other activities related to analytical work, such as providing proficiency tests, producing reference materials or accrediting any such activity? Do you teach or study subjects related to measurements? Do you use measurement results or prescribe how to use them? If the answer is yes to any of these questions, the following reference documents are also for you.

You talk, we understand – The way out of the tower of Babel

Visit the LabRulez booth at <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/events/871">analytica 2026</a> in Munich, 24. - 27. March 2026! You can find us in Hall A1, Booth A1.506. At the booth, you will be able to explore live demonstrations of how the LabRulez portals work and see selected analytical instruments from our pre-owned marketplace section.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Lab_Rulez_at_Analytica_2026_Floor_plan_55e1057e03.jpg" alt="LabRulez at Analytica 2026: Hall A1 Floor Plan and Booth Location" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Lab_Rulez_at_Analytica_2026_Floor_plan_55e1057e03.jpg 245w," sizes="100vw" width="1516" height="881"><h3>Would you like to learn how the LabRulez portals work?</h3>➡︎ <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/">LabRulezLCMS</a> ➡︎ <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/">LabRulezGCMS</a> ➡︎ <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/">LabRulezICPMS</a><ul><li>A unique online solution for your marketing</li><li>A targeted audience from the analytical chemistry community</li><li>Modern technologies and a unique concept</li><li>Design optimized for most smart devices – PC, mobile, and tablet</li><li>Advanced statistical tools fully available to users</li></ul><h3>Services Offered</h3><h4>News + Company Updates</h4><ul><li>Publish news related to your instrumentation, applications, services, events, job openings, and more</li><li>News is shared both on our portals and across our social media channels</li></ul><h4>Library – All Documents in One Place</h4><ul><li>Applications, posters, presentations, technical articles, brochures, specifications</li><li>Fast and advanced search capabilities</li><li>Over 32,000 documents currently available in our database</li></ul><h4>Webinars</h4><ul><li>Upcoming and on-demand webinars from the field of analytical chemistry</li><li>More than 5,500 webinars covering chromatography, mass spectrometry, and spectroscopy</li></ul><h4>Careers</h4><ul><li>Targeted job listings in analytical chemistry</li><li>Clear filtering by specialization or location</li><li>Increased visibility for job postings</li></ul><h4>Companies</h4><ul><li>Company profile with key information and contacts</li><li>Integration of all your activities on our portal: News, Library documents, Webinars, Upcoming Events, Careers, and mentions by partners or customers</li><li>Connection to your Products listed on LabRulez portals</li></ul><h4>Products and Services</h4><ul><li>Comprehensive overview of instrumental techniques and services</li><li>Targeting the analytical chemistry community and customers in the growing online environment</li></ul><h4>Marketplace</h4><ul><li>Buying and selling pre-owned analytical equipment</li><li>We purchase analytical instrumentation of all brands and ages</li><li>Sell your equipment through LabRulez</li><li>Request and purchase complete systems, modules, or spare parts with warranty and service</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Lab_Rulez_at_analytica_2026_bazar_7edf4a0872.jpg" alt="LabRulez at analytica 2026" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Lab_Rulez_at_analytica_2026_bazar_7edf4a0872.jpg 88w," sizes="100vw" width="1600" height="2844"><h3>What Will Be on Display at Our Booth?</h3>Come and explore selected spare parts and modules from our marketplace section. These include both new, tested, and pre-owned items.<h4><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/bazaar">LabRulezLCMS Marketplace</a></h4>Spare parts for LC/MS:<ul><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/bazaar?category=378">Vacuum turbo pumps for LC/MS</a></li></ul>Spare parts for HPLC:<ul><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/bazaar?category=397">Degassers for HPLC/UHPLC</a></li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/bazaar?category=368&amp;search=valve">Automatic valves for HPLC</a></li><li>HPLC components for Agilent 1100, 1200, and 1260 Infinity II series</li></ul>Consumables:<ul><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/bazaar?category=377">HPLC lamps</a></li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/bazaar?category=48">HPLC columns</a></li></ul><h4><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/bazaar">LabRulezGCMS Marketplace</a></h4>Spare parts for GC/MS:<ul><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/bazaar?category=367&amp;search=turbo">Turbo pumps for GC/MS</a></li></ul>Spare parts for GC:<ul><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/bazaar?category=366&amp;search=EPC">EPC modules</a></li></ul>Sample injection<ul><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/bazaar/432">Autosampler 7693A for GC</a></li></ul>Consumables:<ul><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/bazaar?category=7">GC columns </a>and selected accessories</li></ul>

LabRulez at analytica 2026

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Eurachem is a European network promoting international traceability of chemical measurements and good analytical practice. It provides expert guidance, supports method validation, uncertainty evaluation, proficiency testing, and facilitates discussion on technical and policy issues in analytical quality.

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ARC GCxGC Xpansion

ARC’s simple stop-flow modulator can be installed in minutes and turn any GC into a powerful multi-dimensional separation machine. ARC’s modulator emphasizes robustness, simplicity, and ease of use to allow anyone from a novice GC user to a veteran expert to generate valuable chemical data on the most complex samples. 

<h3>No-fuss GCxGC solution</h3>
This affordable package includes free, open-source software (visualization only), and ARC’s lifetime support. For power users we offer GC Image software. 
<h3>Why choose us?</h3>
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<li>Affordable</li>
<li>Robust design</li>
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<li>Easily switch between 1D and 2D GC</li>
<li><a href="https://www.activatedresearch.com/gcxgc_vis/">Free visualization software</a></li>
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<h3>Why should I use GCxGC?</h3>
The separation of compounds by gas chromatography is typically performed using a single analytical column. As samples become more complex, it can become difficult to separate all the compounds from each other and they can start to overlap, or co-elute. Longer or narrower columns can be used to increase resolving power, but with diminishing returns.
Comprehensive two-dimensional GC, or GCxGC, drastically increases separation power by adding a second analytical column after the first column. A modulator placed between the two columns pulses the analytes from the first column onto the second column. When the columns are orthogonal in separation power, this technique can result in an order of magnitude increase in the number of analytes that can be detected.
ARC’s solution takes advantage of stop-flow modulation to make GCxGC an attainable configuration for any analytical laboratory. It involves continually sampling the effluent from the first column into an accumulator tube and re-injecting it onto a second, smaller column with orthogonal separation. This second separation happens in the time it takes to accumulate the next sample. The pulse time is known as the modulation time.

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LabRulez at analytica 2026

VOC Analysis in Drinking Water: Achieving ppt-Level Sensitivity with ITEX Dynamic Headspace GC-MS

You talk, we understand – The way out of the tower of Babel