Can You Use 100% Water with a C18 column?

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Have you ever wondered if you can run your C18 column with 100% water?

Here’s the straightforward answer: We don’t recommend using 100% water with a C18 column.

Why do we advise against it. The reason lies in the nature of the C18 itself. Known for its hydrophobic characteristics, the C18 has a strong aversion to water. When faced with pure water, the C18s don’t maintain their intended structure. Instead, they undergo a drastic change, collapsing and transforming from their robust form into ineffective, tiny C2 nubs. This occurrence, termed phase collapse, leads to a significant decline in chromatography efficiency, affecting the separation quality and reproducibility of your results.

Reviving Your C18 Column if 100% water was used

Fear not; this isn’t a permanent setback. By reintroducing 100% acetonitrile or 100% methanol, the column can be rejuvenated. These solvents effectively resolvate the column, restoring its functionality and ensuring it’s ready for future use. This resilience of the C18 column highlights its robust design, allowing for recovery from suboptimal conditions without compromising its long-term usability.

Optimal Organic Content: Staying Above 10%

A crucial guideline for C18 column maintenance is to maintain a minimum of 10% organic content. This is not an arbitrary number; it’s a balance between maintaining column integrity and achieving optimal chromatographic separation. Keeping at least 10% methanol or acetonitrile in the column during chromatography is a conservative yet effective strategy. For those inclined to experiment, reducing the organic content to 5% might be tempting. However, proceed with caution. Lower organic levels can lead to phase collapse, marked by reduced retention times and capacity factors, compromising the column’s efficiency and the reliability of your results.

Conclusion: The Key to Consistent Results

In conclusion, maintaining at least 10% organic content in your C18 column is critical for its optimal performance. This practice not only ensures the longevity and effectiveness of the column but also guarantees consistent, high-quality chromatography results. A small investment in careful maintenance goes a long way in securing reliable and reproducible outcomes in your chromatographic endeavors.

If you are working with very polar molecules you will need a polar embedded phase column. Learn more here.

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