More Chemistries, More Choices for Separation
The InfinityLab Poroshell 120 family from Agilent continues to expand, offering three particle sizes and more than 20 chemistries to support a wide range of analytical applications. This flexibility allows chromatographers to separate everything from small molecules to more complex biomolecules. Choosing the right InfinityLab Poroshell column depends on the method goal, instrument capability, and required selectivity.
Understanding the Importance of Column Particle Size
Particle size is one of the most important variables in HPLC method optimization because it directly affects efficiency, resolution, and backpressure. InfinityLab Poroshell columns are available in 1.9 µm, 2.7 µm, and 4 µm particle sizes, each designed for different performance requirements.
- 1.9 µm: Highest efficiency and UHPLC-level resolution, but requires systems that can handle higher backpressure
- 2.7 µm: Balanced performance and pressure, often ideal for many HPLC systems
- 4 µm: Lower backpressure for standard HPLC operation while still providing strong resolution
Smaller particles improve efficiency but also increase system pressure. Larger particles generally reduce pressure and may offer greater compatibility with conventional HPLC instruments. Selecting the right particle size depends on method requirements, allowable pressure, and desired throughput.
Figure 1: Particle Size Guideline
Choosing the Right Column ID and Length for Your HPLC Method
After selecting particle size, column inner diameter (ID) and length are important variables that influence method performance. Column ID affects sample loading, sensitivity, and solvent consumption, while column length affects separation efficiency and total run time.
- Column ID: Traditional 4.6 mm columns remain common, while narrower 2.1 mm and 3.0 mm columns reduce solvent use and can improve sensitivity
- Column Length: Shorter columns such as 30–100 mm support fast separations, while longer columns above 150 mm improve resolution and peak capacity
Balancing particle size, column ID, and column length helps optimize speed, pressure, and chromatographic sharpness for a given application.
Comparing Poroshell Chemistries to ZORBAX Chemistry-Based Methods
Moving from fully porous columns to superficially porous columns can provide meaningful improvements in speed and efficiency. The InfinityLab Poroshell 120 family mirrors many established Agilent ZORBAX chemistries, which makes method transfer more straightforward for many laboratories.
| InfinityLab Poroshell Chemistry | Aligned Chemistry |
|---|---|
| InfinityLab Poroshell 120 EC-C18 | ZORBAX Eclipse Plus C18 |
| InfinityLab Poroshell 120 EC-C8 | ZORBAX Eclipse Plus EC-C8 |
| InfinityLab Poroshell 120 Phenyl-Hexyl | ZORBAX Eclipse Plus Phenyl-Hexyl |
| InfinityLab Poroshell 120 SB-C18 | ZORBAX StableBond SB-C18 |
| InfinityLab Poroshell 120 SB-C8 | ZORBAX StableBond SB-C8 |
| InfinityLab Poroshell 120 Bonus-RP | ZORBAX Bonus-RP |
| InfinityLab Poroshell 120 SB-Aq | ZORBAX StableBond SB-Aq |
| InfinityLab Poroshell 120 EC-CN | ZORBAX Eclipse XDB-CN |
| InfinityLab Poroshell 120 HILIC | ZORBAX HILIC Plus |
When transferring a method, it is generally best to match the particle size, column ID, and column length used in the existing ZORBAX method as closely as possible. Minor adjustments to flow rate, temperature, or gradient slope may still be needed to reach optimal separation.
Exploring the Variety of Poroshell Chemistries Available
Agilent offers a broad range of Poroshell chemistries to support everything from general-purpose methods to specialized pH and polarity conditions. Examples from the InfinityLab Poroshell 120 family include:
for Low pH Stability
for High pH Applications
or Aqueous Phases
for Unique Selectivity
For a broader overview of available phases, see Agilent’s InfinityLab Poroshell column guide. This range of chemistries allows chromatographers to match column selectivity more precisely to sample type and mobile phase conditions.
- Choose the most appropriate particle size, column ID, and length based on the method objective and instrument capability
- Optimize mobile phase composition, gradient profile, and temperature for the best separation
- Use Chrom Tech technical support when developing or troubleshooting Poroshell-based methods
With the right Poroshell configuration, chromatographers can improve throughput, maintain reproducibility, and achieve strong separation performance across a broad range of HPLC methods.