Frances Carroll (Presenter)
Restek Corporation
Authorship: Frances Carroll, Sharon Lupo, Shun-Hsin Liang, Ty Kahler, Paul Connolly
Restek Corporation, 110 Benner Circle Bellefonte, PA 16823
| Short Abstract Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most common medications worldwide for the treatment of pain, fever, and inflammation. Although NSAIDs are generally considered safe, long-term use can result in renal failure or serious gastrointestinal and cardiovascular side effects. Monitoring their use can help prevent drug interactions and to minimize side effects. For this analysis, the combination of the Raptor™ Biphenyl column, use of scheduled polarity switching, and selection of mobile phases that maximized sensitivity in both positive and negative ion modes allowed the simultaneous detection of 27 NSAIDs (plus acetaminophen) in one fast 8.5 minute analysis. |
Long Abstract
Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most common medications worldwide for the treatment of pain, fever, and inflammation in humans and livestock. They comprise a structurally diverse group of compounds that have similar physiological effects. Although NSAIDs are generally considered safe in humans, long-term use can result in renal failure or serious gastrointestinal and cardiovascular side effects such as ulcers and heart attacks. NSAIDs are monitored in humans to prevent drug interactions and to minimize side effects; while residues are monitored in animal products prior to human consumption to prevent toxicity. For this analysis, the combination of the Raptor™ Biphenyl column, use of scheduled polarity switching, and selection of mobile phases that maximized sensitivity in both positive and negative ion modes allowed the simultaneous detection of 27 NSAIDs (plus acetaminophen) in one fast 8.5 minute analysis.
During method development, several conditions were optimized in order to create a fast and sensitive polarity switching method for the major NSAID classes including acetic acids, COX-2 inhibitors, fenamates, oxicam derivatives, propionic acids, and salicylates. Conditions investigated include mobile phase, gradient, and polarity considerations for enhanced selectivity and sensitivity of all NSAID classes. In addition, run time and data speed were tested to ensure instrumentation capabilities were not exceeded. For all experiments, analytes were diluted in water and injected into a Shimadzu Nexera UHPLC equipped with a SCIEX Triple Quad 4500 System. Detection was performed using electrospray ionization in positive and negative ion modes using multiple reaction monitoring (MRM).
During mobile phase investigations, scouting gradients were utilized to determine which organic solvent and additives would result in the best sensitivity and peak shapes. Solvents tested included water, methanol and acetonitrile modified with LC-friendly buffers and acids. Polarity was assessed simultaneously by running each scouting gradient in positive and negative ion mode and recording the response for each analyte. Analyte responses were ranked for each ionization polarity and mobile phase combination. It was found that water and acetonitrile mobile phases containing 0.1% formic acid and 5 mM ammonium formate provided the best overall retention and response for most analytes. Several modifications were made to the LC gradient and scheduling of the polarity switching method to ensure scan rates and retention time windows were optimized so sufficient data points were collected for each analyte.
The final scheduled MRM separation was performed using water and acetonitrile mobile phases modified with 0.1% formic acid and 5 mM ammonium formate under gradient conditions on a Restek Raptor™ Biphenyl 2.7µm, 100 x 2.1mm column equipped with a Raptor™ Biphenyl EXP® 2.7µm, 5 x 2.1mm guard column. The gradient run time was 6.5 minutes, with a total cycle time of 8.5 minutes. Of the NSAIDs, 13 were analyzed in positive ion mode, and 14 were analyzed in negative ion mode.
References & Acknowledgements:
| Description | Y/N | Source |
| Grants | no | |
| Salary | no | |
| Board Member | no | |
| Stock | no | |
| Expenses | no |
IP Royalty: no
| Planning to mention or discuss specific products or technology of the company(ies) listed above: | no |