Sample extraction with Centri® – the customer viewpoint
20 September 2021
Who uses Centri – and for what?
Food, Flavour, Fragrance
Our customers use Centri for numerous applications. Early adopters of the technology used it for aroma profiling of foods, beverages and fragranced consumer products. The combination of conventional techniques, such as solid-phase microextraction (SPME), with our world-leading trap technology enriches customers’ samples, enhancing the quality and quantity of information they get. This enables them to check the quality and authenticity of their products with confidence, so that their own customers can be sure they are not receiving an inferior product – protecting brand reputation and minimising loss of revenue. The same methods can also be used for competitive product comparisons or identifying the source of any customer complaints with a product.
We’ve seen Centri being applied to environmental monitoring applications such as detecting trace-level odours in water, a major source of complaints to water companies.
Identifying an odour, finding the source and treating the water while ensuring it’s safe to consume afterwards requires a fast turnaround. However, to achieve the sensitivity required, manual and time-consuming techniques such as solid-phase extraction (SPE) are typically used.
With Centri, preconcentration of target analytes on a high-capacity phase with HiSorb™ means that more of each analyte is extracted for detection without manual preparation steps, enhancing the sensitivity while placing fewer demands on the analyst. HiSorb is fully automated on Centri, which means that customers benefit from simultaneous sample extraction in which the next sample is ready to be analysed as soon as the gas chromatograph (GC) becomes ready again. This means that the overall run time of every sample is significantly reduced, allowing a fast response when needed.
More recently, the technology has been used by the defence industry. Here, customers appreciate the modularity of the system. One customer replaced an ageing tube-based thermal desorption (TD) system with Centri containing the tube analysis module to start with, so that they could continue with existing workflows. They later upgraded to include all the injection modules – headspace, SPME and HiSorb – for newer projects that required different sampling methods.
Breath sampling for biomarker discovery is a growing field in which researchers are moving towards non-invasive sampling techniques to identify volatile compounds as early indicators of diseases. Centri has allowed researchers to extend their analytical capabilities to find biomarkers of different diseases in other biological matrices such as urine and saliva.
Customer challenges and how Centri tackles them
Centri has opened the door to the analysis of liquids, which can be difficult using sorbent tubes when samples have a high moisture content. The presence of water or moisture in a sample is a common challenge for many of our customers, because if water reaches the GC, it can have a negative effect on the chromatography and it reduces column and detector lifetimes.
Centri solves the problem. After transferring the extracted analytes to the trap, the trap can be purged with a flow of carrier gas away from the GC, which means that residual moisture injected along with the sampled analytes can be removed before it reaches the column.
The focusing step also preconcentrates the analytes into a narrow band of vapour when injected to the GC. This sharpens the chromatographic peaks, which significantly improves the sensitivity achieved.
What makes Centri unique and why?
Our technology has a range of different benefits but one that’s worth mentioning is re-collection. This allows the user to collect the split portion of the sample onto a clean sorbent-packed tube when it's injected to the GC whereas typically it would go to waste. This is important because if the sample is precious or the extraction protocol is lengthy, the sample can simply be injected into the GC again without repeating the sampling process.
We've been using the re-collection capability for many years with TD but we're now able to employ this with all the sample introduction techniques that use the trap on Centri. So now we can offer re-collection with techniques such as headspace and SPME where it's never been offered before.
Multi-step enrichment (MSE®)
Some customers are benefitting from the trap technology, not only for improved chromatography and water management but also for its unique multi-step enrichment (MSE) capability, which further enhances the quality of information from a sample. MSE involves taking multiple extractions from a sample and loading them onto the focusing trap for a single analysis.
Unattended operation is always a key differentiator, particularly when it comes to HiSorb. Centri automates the entire workflow, from sampling through washing and drying to remove residual matrix to injection to the GC. HiSorb provides robust immersive sampling too, extracting even more information from every sample, allowing our users to gain a deeper insight into sample composition and make better-informed decisions.
What do customers like about Centri?
We know customers are excited by the multiple capabilities Centri has to offer, especially the ability to assess different sampling techniques on a single platform for any new and upcoming projects. It allows them to find the most suitable method for their needs, as well as being able to adapt to ever-changing business demands. To meet customer requirements, our users can easily switch between techniques without needing to do any complicated hardware reconfiguration, so they can quickly assess urgent samples with ease.
Why do customers like working with the Markes team?
The team has a wealth of technical expertise ranging from product to application specialists. We work closely with our customers – from initial discussions all the way through to installations and post-install technical support and training – to ensure that they get the most out of their system.
What we find adds further value to customer relationships is access to our extensive knowledge base, either directly or through our trusted global distribution network. We're easy to contact by email or phone to help our customers with their challenges.