Ibuprofen Lysine

The separation and analysis of complex samples with wide polar range on a singular column is always a difficult problem in separation and analysis science. In this study, the RCC3-R molecular cage modified with the quaternary ammonium salt stationary phase (RCC3-GQ@silica) was successfully prepared and applicated in the separation of wide polar range compounds. In the Reverse Phase Liquid Chromatography (RPLC) mode, due to the hydrophobicity and π-π interactions provided by the cyclohexane and benzene rings in the molecular cage structure, this stationary phase demonstrated effective separation capabilities for alkylbenzenes, polycyclic aromatic hydrocarbons, phenols, and anilines. In the Hydrophilic Interaction Liquid Chromatography (HILIC) mode, the study explored the separation performance of this stationary phase for sugars and inorganic salts. Utilizing a mixed mode of HILIC/RPLC/Ion Exchange Chromatography (IEC), effective separation was achieved for sulfonamides, nucleosides, acids, and amino acids, indicating good separation effects for medium to strongly polar compounds as well as various hydrophilic compounds. Combining various separation modes, the RCC3-GQ@silica stationary phase successfully separated 91 compounds across 15 categories. These results not only demonstrate the potential of the stationary phase in expanding the range of polarities of analyzable compounds and achieving multipurpose use on a single column, but also confirm its effective separation of nucleosides in pure water systems, further emphasizing the significant application potential of RCC3-GQ@silica stationary phase in the field of green chemistry.

Carbamazepine is a versatile pharmaceutical used mainly for epilepsy and mood stabilization, but like all medications, it requires careful monitoring due to its potential side effects and interactions. In the current work, a fluorescent nanosensor was developed for the carbamazepine determination in the exhaled breath condensate (EBC). The nanosensor consists of graphene quantum dots doped with copper (Cu-doped GQDs). The presence of carbamazepine significantly decreased the fluorescence of Cu-doped GQDs, resulting in a quenching effect within a concentration range of 0.02-2.0 µg/mL, which occurs due to dynamic, rather than static, quenching according to Stern-Volmer plot. The relative standard deviations for intra-day and inter-day analysis of carbamazepine were 1.8 % and 4.8 %, respectively. The validated sensor was effectively employed for carbamazepine analysis in EBC of patients receiving the drug.