MobilphaseSystem

MobilphaseSystem is a term used in chromatography to describe the solvent delivery subsystem that provides the mobile phase for transporting analytes through the stationary phase. It includes the solvents, additives, and the hardware that deliver, mix, and regulate the mobile phase, such as solvent reservoirs, degassers, pumps, gradient mixers, flow paths, and associated safety and waste handling components. In liquid chromatography, the mobile phase is a liquid solvent or solvent mixture; in gas chromatography, the mobile phase is a carrier gas (for example helium, nitrogen or hydrogen) that travels through the column.

Common modes of operation are isocratic, where the mobile phase composition remains constant over a run, and gradient, where the composition is varied during the run to improve separation of complex samples. Flow rate, system pressure, solvent composition, pH and ionic strength in buffered systems, and column temperature (for LC) are controlled parameters. The mobile phase must be compatible with the stationary phase and the detector, and solvent purity and degassing are important for reproducible results.

Quality and performance aspects include stable flow with minimal pulsation, low backpressure, and avoidance of air bubbles. Degassed, filtered solvents reduce baseline noise and detector contamination. The mobile phase strongly influences retention, selectivity, peak shape, and detection sensitivity, and is thus central to method development and validation in applications such as pharmaceuticals, environmental analysis, and clinical chemistry.