Pharmaceutical HPLC Equipment

HPLC (known as high performance liquid chromatography, high pressure liquid chromatography) is used to separate the phases of a solid or liquid analyte, regardless of its stability and volatility. HPLC equipment is popular for its regarded ease of set up, use, and configuration potential. The principle of HPLC testing focuses on what occurs when the analyte (compound being analyzed) and a test solvent are pushed under pressure through a column within the HPLC equipment. The solvent strength and the particular flow rate within HPLC equipment affect retention times.

Primary Applications of HPLC

• Identification of compounds
• Characterization of molecular bonds within compounds
• Purity testing
• Molecular quantification

Principles of HPLC Testing Methods

Normal-phase (also known as liquid-solid) HPLC measures the absorption of the analyte on a polar surface. Reversed-phase (RPC) HPLC elutes the analyte based on the relative properties of its mobile phase and the bonded stationary phase. Ion exchange (IEC) HPLC separation occurs by means of ion exchange between the bonded ion group and counter ions. Size exclusion (SEC) HPLC invokes separation based on the size of the molecule being tested and the sieve material used within the HPLC column.

Pharmaceutical Application of HPLC Testing

Every tested compound exhibits a specific retention time upon exiting the column. This retention time, graphically represented as a retention "peak," is unique to each compound and can be used to identify a molecule.  HPLC is useful in compound identification and pharmaceutical purification testing, as it is estimated that over 60% of existing molecules have been uniquely identified by HPLC testing.

Purchasing and Configuring HPLC Equipment

HPLC systems may be integrated/all-in-one or consist of an HPLC instrument and compatible components. It may be necessary to configure an older model HPLC system with very specific HPLC detectors. Vendors offer a range of compatible detectors such as UV-Visible, conductivity, and refractive index detectors. Newer systems such as ultra-high performance liquid chromatographers (UHPLC) are built with high-efficiency considerations.