LCGC Asia Pacific
UltraPerformance LC (UPLC) has been widely accepted by chromatographers because of improvements over HPLC in the sensitivity, resolution and speed of separations. As scientists begin to use this technology for impurity and metabolite profiling, they will need to transfer the methods to preparative LC to isolate and purify their compounds for further research. Therefore, it is necessary to systematically transfer UPLC assays not only to HPLC, but, more importantly, to preparative chromatography. In this application, we provide information on how to scale a UPLC impurity/degradant separation to a preparative LC separation.
UltraPerformance LC (UPLC) has been widely accepted by chromatographers because of improvements over HPLC in the sensitivity, resolution and speed of separations. As scientists begin to use this technology for impurity and metabolite profiling, they will need to transfer the methods to preparative LC to isolate and purify their compounds for further research. Therefore, it is necessary to systematically transfer UPLC assays not only to HPLC, but, more importantly, to preparative chromatography. In this application, we provide information on how to scale a UPLC impurity/degradant separation to a preparative LC separation.
The UPLC separation of the ranitidine degradation sample is shown in Figure 1(a). Ranitidine is clearly resolved from all other compounds in the mixture and the entire cycle time is only 10 min. The boxed peak is the analyte that needs to be collected for identification. The separation is first directly scaled to a 19 × 150 mm XBridge Prep OBD C18 column. This column dimension was chosen to maintain the same column length (L) to particle size ratio (dp) as in the UPLC separation to ensure constant plate count and, therefore, maintain resolution. The XBridge chemistry is built on the same second generation bridged ethyl hybrid (BEH) particle as the ACQUITY UPLC BEH chemistry; therefore, the same selectivity is maintained as we scale separations. As shown in Figure 1(b), to maintain the selectivity and resolution, the overall cycle time needed to be increased to over 88 min. This long cycle time is not very practical for most separation scientists.
Therefore, modification of the gradient profile is necessary to help reduce the cycle time. We started the gradient at a higher % organic, maintained the same gradient slope to separate the component of interest from ranitidine, and quickly ramped to 90% organic to wash all other compounds off the column. The total cycle time has been reduced by 80%. Results are shown in Figure 1(c).
Figure 1
UPLC separations are seamlessly transferred to preparative LC by using traditional scaling principles. Further optimization is easily achieved by simple modification of the gradient profile. The use of the XBridge Prep OBD columns, built on the same base particle as ACQUITY UPLC BEH columns, facilitates this transfer.
© 2007 Waters Corporation. Waters, UPLC, ACQUITY UPLC, UltraPerformance LC, XBridge, OBD, AutoPurification, and The Science of What's Possible are trademarks of Waters Corporation.
Fang Xia, Jie Y. Cavanaugh, Diane M. Diehl, Thomas E. Wheat and Jeffrey R. Mazzeo, Waters Corporation, Milford, Massachusetts, USA.
Waters Corporation
34 Maple Street, Milford, Massachusetts 01757, USA
tel. +1 508 478 2000 fax +1 508 478 1990
Website: www.waters.com
Determination of 3-MCPD and Glycidol in oil by ISO 18363-1, AOCS Cd 29c-13, DGF C-VI 18 (10)
January 28th 2025Fully automated method for 3-MCPD and Glycidol determination in edible oil by GC-MS, based on the widely used methods ISO 18363-1, AOCS Cd 29c-13, and DGF C-VI 18 (10). The automated GC-MS determination of 3-MCPD and glycidol in edible oils with evaporation step and GC column backflush ensures low LODs by eliminating excess derivatization reagent for improved method stability and system ruggedness.
Determination of 3-MCPD, 2-MCPD and Glycidol in oil and fat by ISO 18363-4 Zwagerman/Overman
January 28th 2025Fully automated method for 3-MCPD, 2-MCPD and Glycidol determination in Edible Oil and Fat based on ISO 18363-4 - Zwagerman/Overman with validation data. A recent upgrade to PTV injection has further improved the quality and robustness of results. Fatty acid esters of 3- and 2-monochloropropanediol (3-MCPD-e, 2-MCPD-e) and glycidol (Gly-e) are process contaminants that are formed, for example, when edible oils and fats are refined. After ester cleavage during digestion in the human body they pose a relevant health risk and therefore need to be determined in edible oils and fats and in fat containing food.
Automated Analysis of MOSH/MOAH in food and packaging extracts by LC-GC-FID
January 28th 2025The AppNote describes the fully automated determination of MOSH/MOAH in Food and Packaging extracts following DIN EN 16995. Industrial production, processing and transportation invariably put food at risk of contamination with MOSH/MOAH. To ensure a reasonable cost benefit balance, high laboratory productivity and good quality of results, leading contract laboratories increasingly strive to automate their processes. An example is the determination of MOSH/MOAH using a LC-GC-FID Coupling Platform. Depending on the sample matrix, additional automated sample preparation by aluminum oxide clean-up, epoxidation, and/or saponification is necessary prior to analysis. The dedicated evaluation software integrates the complex MOSH/MOAH chromatograms accurately and reproducibly.
Testing Solutions for Metals and PFAS in Water
January 22nd 2025When it comes to water analysis, it can be challenging for labs to keep up with ever-changing testing regulations while also executing time-efficient, accurate, and risk-mitigating workflows. To ensure the safety of our water, there are a host of national and international regulators such as the US Environmental Protection Agency (EPA), World Health Organization (WHO), and the European Union (EU) that demand stringent testing methods for drinking water and wastewater. Those methods often call for fast implementation and lengthy processes, as well as high sensitivity and reliable instrumentation. This paper explains how your ICP-MS, ICP-OES, and LC-MS-MS workflows can be optimized for compliance with the latest requirements for water testing set by regulations like US EPA methods 200.8, 6010, 6020, and 537.1, along with ISO 17294-2. It will discuss the challenges faced by regulatory labs to meet requirements and present field-proven tips and tricks for simplified implementation and maximized uptime.
A Guide To Finding the Ideal Syringe and Needle
January 20th 2025Hamilton has produced a series of reference guides to assist science professionals in finding the best-suited products and configurations for their applications. The Syringe and Needle Reference Guide provides detailed information on Hamilton Company’s full portfolio of syringes and needles. Everything from cleaning and preventative maintenance to individual part numbers are available for review. It also includes selection charts to help you choose between syringe terminations like cemented needles and luer tips.