Improving Efficiency by Changing Small Habits in Chromatography Column Usage

Laboratory consumables purchasing budgets are being squeezed... Sometimes we are forced to confront such objective circumstances during experiments, especially when making the most of expensive consumables.

Today, let's use expensive chromatography columns in laboratory consumables as an example and provide some cost-saving measures. By adopting preventive and maintenance techniques, we can extend the lifespan of chromatography columns, reduce the frequency of column purchases, and achieve cost-effectiveness improvements.

Here's an example:

A chromatography column is discarded after 2000 injections. If the lifespan of the chromatography column can be extended to 4000 injections, the purchase cost of columns can be halved!

Let's see which small habits we can change!

01 Strengthening the management of mobile phase

Mobile phase filtration, storage, and replacement precautions.

Refer to "How to Achieve Optimal Mobile Phase Performance:6 Key Points" for details.

Check if the pH of the mobile phase is within the tolerance range of the column.

Mobile phases outside the tolerance range can cause relatively rapid and irreversible damage to the column.

High pH of the mobile phase leads to dissolution of the stationary phase.

For example, if the pH of the mobile phase is less than 2.0, you can choose the Welch LP series chromatography columns (pH tolerance range 0.5-8.0). If the pH of the mobile phase is greater than 10.0, you can choose the Welch Hybrid Silica Xtimate® series chromatography columns (pH tolerance range 1.0-12.5). If using 100% aqueous phase, options like AQ, Alk, Polar RP, LP, etc., can be considered.

 

The shelf life of the mobile phase is also an easily overlooked factor.

Expired mobile phases may affect the analysis results, and if microbial growth occurs, entering the column can lead to damage. There isn't a unified standard for this; generally, each company formulates its own SOP (Standard Operating Procedure), but chromatography column manufacturers usually have stricter requirements.

For example, pure aqueous and pure salt mobile phases can be prepared as needed in the summer (within 12 hours for other seasons); for pharmaceutical companies conducting stability tests, mobile phases cannot be prepared as needed and must be stored in the refrigerator and used within 3 days. Salt-containing mixed mobile phases should be used within 24 hours.

Welch Materials has always advocated for paying attention to the shelf life of mobile phases.

However, in practice, the number of customers who actually follow this procedure is few. One reason is the inconvenience and perceived lack of necessity, especially since there are company SOPs to reference. Another reason is the desire to avoid wasting mobile phases. Additionally, the impact of the mobile phase on the column is cumulative, and it can be difficult to determine if the column's ultimate failure was due to the mobile phase. However, in reality, only the mobile phase and the sample enter the column. Therefore, changing our habits regarding the treatment of the mobile phase becomes one of the important ways to protect the chromatography column.

Other impacts of the mobile phase on the column.

 

02 Using guard columns or inline filters

For samples with a high degree of contamination, using guard columns is absolutely necessary, especially in the case of pharmaceuticals, natural products, food testing, etc. Particulate matter, strongly retained substances, strong acids, or strong alkalis in the sample can cause increased column pressure, decreased column efficiency, modification of the packing material, deterioration of peak shapes, etc. Even with flushing methods, it is often difficult to restore the column, posing a significant threat to the lifespan of the chromatography column.

Seeing this point, some colleagues may have doubts: wouldn't purchasing guard columns increase costs?

In our experience with chromatography columns returned for maintenance, we have found that the majority of issues are due to clogged column frits and contaminated column heads (with contamination depths of nearly 1 centimeter), as shown in the figure below:

Column frit contamination (leading to increased column pressure, poor peak shapes, and reduced separation efficiency).

(Column head packing contamination, requiring replacement of the column head packing).

Replacing column frits and column head packing is not something that ordinary users can easily accomplish. Even with factory repairs, it cannot guarantee a 100% restoration of performance. However, adding an inline filter can easily prevent column frit clogging, and adding a guard column can prevent contamination of the column head packing.

Most importantly, guard columns are cheaper than chromatography columns! Welch's column packing material is exactly 1 centimeter, which can perfectly replace the column head packing to withstand contamination. A column packing material costs just over 100 yuan, saving the cost of one column.

03 Pay attention to the daily maintenance and flushing of chromatography columns

Apart from the above two key points, here are some daily maintenance tips that we often talk about, compiled together for your convenience, for easy reference and bookmarking:

1. Daily maintenance flushing.

Refer to: "Insights into the Use and Maintenance of Liquid Chromatography Columns - All for You!"

2. Unused chromatography columns for a long time.

Refer to: "Unused Chromatography Columns for a Long Time: Does it Affect Lifespan?"

3. Avoid high-pressure impacts.

Although chromatography columns can withstand high pressures, sudden pressure shocks should be avoided. It is recommended to start activation and equilibration with a low flow rate, gradually increasing to the experimental flow rate once stabilized.

4. Learn more about chromatography column maintenance.

Stay tuned to Welch's website and social media channels for more updated information on chromatography column usage and maintenance.