35 Will a C18 cover all your needs in HPLC?
The short answer is, of course, no. Yet, a C18 might be the most versatile phase and a first pick when developing analysis or purification methods for HPLC. However, when working with biomolecules and polar compounds, one may need to play with other parameters than hydrophobicity, like total charge at various pH as well as being able to run in highly aqueous conditions. In those situations, the boundaries of a traditional silica-based C18 might show some limitations: jeopardising the chemical stability of the phase at high pH or having issues to obtain any substantial sample retention in a water-rich mobile phase. Kromasil offers C18 alternatives to cover extended conditions: Kromasil EternityXT C18 and Kromasil Classic C18(w).
These two C18 alternatives are highly typical when it comes to hydrophobicity and IEX capacity at lower pH; as can be seen in the Tanaka test diagram. The other tested properties show differences that can give alternatives to reach separation goals.
In an example separating alkaloids, much better selectivity can be achieved at high pH when selecting Kromasil EternityXT C18, but still be confident that the stationary phase will not be impaired by running under those harsh conditions over a long time. Also, under reversed phase conditions, slightly different selectivity can be obtained with a wettable C18(w) compared to a classic C18. In the second example, an expected similarly strong hydrophobic retention is obtained for toluene, while caffeine, that has a notoriously weak retention on a classic C18, is substantially retained on the wettable C18(w). This is due to the interactions of polar compounds with the polar end-capping of the phase, enabling the ability to operate in fully aqueous conditions without risk for phase dewetting.
More information online:
ilmt.co/PL/DKl1 and
ilmt.co/PL/WV9P
New chemometrics platform transforms complex data into meaningful results
Sepsolve Analytical Ltd has announced the launch of a ground-breaking new addition to its software suite: ChromCompare+™ is a powerful, yet easy-to-use, chemometrics platform for comparing multiple GC and GC×GC chromatograms and extracting useful insights into the constituents that are present. Crucially, it offers the flexibility to process data from a broad range of GC and GC-MS platforms.
“I am confident that ChromCompare+ is the final piece of the puzzle for discovery workflows,” said Laura McGregor, SepSolve’s Product Marketing Manager. “Our innovative approach means we can reduce the risk of missing important differences between sample classes, and allow users to automatically classify unknown samples - without having to be experts in statistics.”
This is particularly valuable in discovery workflows, such as clinical research, food and beverage authenticity or fragrance profiling, when analysts don’t know the important differences between sample classes, so must investigate all components, often within complex matrices. Dr McGregor explained: “ChromCompare+ allows maximum analytical information to be automatically extracted from the raw data and filtered down to the most significant differences between samples. This not only reduces the risk of trace peaks
being ignored, it also minimises the need for error-prone and time-consuming manual processing, thereby increasing the reliability of the entire data processing protocol, from start to finish.”
Andy Hardwick, Commercial Director of SepSolve’s parent company, Schauenburg Analytics Ltd, commented: “We believe that ChromCompare+ offers the ultimate in discovery workflow chemometrics. Furthermore, combining it with the enhanced separation offered by SepSolve’s INSIGHT® GC×GC flow modulator and highly-sensitive detection by BenchTOF™ time-of-flight mass spectrometers, means you can gain even greater insight into sample compositions, resulting in faster yet deeper, more comprehensive, end-to-end analysis.”
More information online:
ilmt.co/PL/5gYv
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