MOPS

Rehm S, et al. Journal of Pharmaceutical and Biomedical Analysis, 2020, 186, 113289.

3-Morpholinopropanesulfonic acid (MOPS) is employed as a stabilizing agent in the analysis of antibiotics in biological fluids, particularly in plasma and cerebrospinal fluid. In the presented high-performance hydrophilic interaction chromatography (HILIC) method coupled with tandem-mass spectrometry (LC-MS/MS), MOPS is used in a 0.5 M solution with ethylene glycol (1:1) to ensure the stability of cefepime, meropenem, and imipenem during sample preparation and storage. This stabilization step is critical in preventing the degradation of these antibiotics, ensuring accurate quantification. The method, which also includes protein precipitation and the use of deuterated internal standards, provides a fast and efficient sample preparation process. MOPS's role in maintaining the integrity of analytes supports the method's high precision and accuracy in therapeutic drug monitoring, as evidenced by the intra- and inter-day imprecision values being below 10% for plasma and 13% for cerebrospinal fluid.

Xue S, et al. Journal of Pharmaceutical and Biomedical Analysis, 2019, 170, 30-39.

3-Morpholinopropanesulfonic acid (MOPS) plays a crucial role in stabilizing tebipenem (TBPM) during plasma sample preparation for ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis. In this method, MOPS is used at a concentration of 50 mM (pH 7.0) as part of a single-step protein precipitation procedure with acetonitrile. The inclusion of MOPS ensures the stability of TBPM in plasma samples, preventing degradation during storage and analysis. This stability is critical for accurate quantification, with the method demonstrating linearity over the analytical range of 0.1-20 μg/mL and a low limit of quantification of 0.1 μg/mL. The method showed minimal matrix effects, high recovery (90.19-95.74%), and excellent stability across various storage conditions, including room temperature and freezing.