|Mobile Phase Preparation for UHPLC: Membrane Filtration Method Affects System Performance and Leaching of Extractable Impurities|
Subodh Kulkarn(1), Jesmi George(2) and Vivek Joshi(2) (1) Millipore India Pvt. Ltd., Bioscience Division, 50A, 2nd Phase, Ring Road, Peenya, Bangalore, India 560058 (2) Millipore Corp., Bioscience Division, 17 Cherry Hill Drive, Danvers, MA 01923
UHPLC/UPLC® is a revolutionary chromatography technique that is gaining wide acceptance among researchers due to improved resolution, shorter chromatographic runs, and the capability for doing fast method development. The presence of sub-2 µm particles in UHPLC columns provide these benefits but also poses challenges in sample and mobile phase preparation. Particulate impurities in the sample or mobile phase can cause backpressure buildup in the UHPLC system, causing system failure. In fact, most UHPLC instrument vendors recommend filtration of mobile phase using 0.2 µm filters, but there is a lack of data showing the benefits of filtration. In this article we describe the filtration of mobile phases through syringe filters of varying pore size and membrane type, followed by analysis by UHPLC and mass spectrometry. Our results clearly indicate that filtration of mobile phase components using the optimal membrane filter will help protect UHPLC systems from particulate impurities that may clog and shut down the system, increase the sensitivity of detection, and improve the accuracy of quantitation.Full Text Article
|IC Millex®-LG and LH Ion Chromatography Certified Syringe Filters|
- Low binding membrane
- Low IC extractables
- Clarifies both aqueous and mild organic solutions
The low binding, low extractable polytetrafluoroethylene (PTFE) membrane removes particulates from aqueous and mild organic solvents for cleaner IC spectra. The housing is made from a low-extractable, high density polyethylene (HDPE). In addition, each unit is individually packaged to minimize the risk of extraneous ionic contamination.
IC Millex filter units are available in two pore sizes and two diameters. The 13 mm units are recommended for filtering volumes from 1 to 10 mL. The 25 mm units are recommended for filtering volumes from 10 to 100 mL.
Each lot of filter units is tested to ensure it complies with Millipore's quality control standards. Lot release criteria include: bubble point, flow rate, housing pressure, downstream particles, and IC levels. A certificate of quality with complete specifications is included in each box.
Some PTFE membrane containing products may be limited to specific applications. Those products will contain an inset specifying the limits of use.
|Ion extractable levels*|
|Effluent particles > 10 µm|
|< 50 particles/unit|
|*Determined by ion chromatography|
Non-sterile ion chromatography (IC) Millex® syringe filters with hydrophilic PTFE membrane provide the lowest IC extractable levels and broad chemical compatibility with both aqueous and organic solutions. Syringe filters are available in two pore sizes and two diameters to optimize results. The housing is made from a low-extractable, high density polyethylene (HDPE). In addition, each unit is individually packaged to minimize the risk of extraneous ionic contamination. Lot release criteria include bubble point, flow rate, housing pressure, downstream particles, and IC levels. A certificate of quality with complete specifications is included in each box.
Features & Benefits
- Lowest level of IC extractables, optimizing background levels in sensitive IC analyses
- Compatible with both aqueous and organic solutions, offering broad chemical compatibility and flexibility in the lab
- Each lot is certified to contain low ion extractable levels
- Available in 0.20 µm and 0.45 µm pore sizes and two diameters to suit your application needs
|13 mm Millex® Filter||25 mm Millex® Filter|
|Inlet Fittings||Female Luer-Lok®||Female Luer-Lok®|
|Outlet Fittings||Male Luer-Slip™||Male Luer-Slip™|
|Filtration Area||0.65 cm²||3.9 cm²|
|Process Volume||10 mL||100 mL|
|Hold-up Volume||< 25 µL after air purge||< 100 µL after air purge|
|Maximum Inlet Pressure, bar (psi)||7 bar (100 psi)||7 bar (100 psi)|
|Maximum Operating Temperature||45 °C||45 °C|
Flow Rate at 25 °C
|13 mm||25 mm|
|IC Millex-LG Filter Unit||15 mL/min at 2 bar (30 psi)||90 mL/min at 2 bar (30 psi)|
|IC Millex-LH Filter Unit||3 mL/min at 0.7 bar (10 psi)||55 mL/min at 0.7 bar (10 psi)|