What are the typical components of an HPLC system?

HPLC systems can be as varied as the type of analyses that can be performed. However, the typical system can be broken down to some basic components which are easily identified in most systems. The best way to identify system components is to follow the flow path of the mobile phase from beginning to end. First, there is the MOBILE PHASE RESERVOIR, which houses the solvent mixture used during the analyses.

The second component is the PUMP, which offers back-pressure regulator controlled flow of the mobile phase through the rest of the system. In most instruments, the mobile phase is degassed prior to entering the pump to reduce dissolved oxygen and bubbles, which can negatively impact chromatography results. This is often done by flowing the solvent through a DEGASSER comprised of a gas permeable membrane and vacuum source. Incidentally, it is vitally important that a pump function very well in order to insure reproducibility in chromatographic data.

The third component is the INJECTION VALVE, used to introduce a set volume of sample into the solvent stream.

Fourth is the COLUMN, often referred to as the “heart” of the HPLC system. It is here that the actual separations occur; without the column, no usable data can be obtained.

Fifth in the system is the DETECTOR. This instrument is vital, as it generates an electronic signal that can be interpreted into a trace. Quantifiable data is obtained by thorough examination of this trace.

Sixth is the WASTE RESERVOIR. Here the mobile phase and analyzed samples collect after passing through the rest of the system.

Last in our basic breakdown of an HPLC system is a RECORDER. While solvent does not come in contact with or pass through this instrument, the recorder is responsible for translating the electronic signal being generated from the detector into a printed trace, referred to as a chromatogram. Using mathematical formulas, analytical information can be gleaned from this chromatogram.