Refurbished HP 1050, Agilent 1100 and Waters systems

The goal of any chemical analysis is to separate a sample (blood, urine, water from a well, etc.) into its individual components in order to evaluate each component free from interference from the other components. Chromatography is a general technique that separates a mixture into its individual components. Those components are referred to as analytes--the chemical compounds of interest to the analyst. Chromatography is then coupled with a detection system that can characterize each type of analyte appropriately. High performance liquid chromatography (HPLC) is one such method. It is used to analyze liquid samples or the liquid extract of a sample.

The fundamental basis for HPLC consists of passing a sample (analyte mixture) in a high pressure solvent (called the mobile phase) through a steel tube (called a column) packed with sorbents (called the stationary phase). As the analytes pass through the column they interact between the two phases--mobile and stationary--at different rates. The difference in rates is primarily due to different polarities for the analytes. The analytes that have the least amount of interaction with the stationary phase or the most amount of interaction with the mobile phase will exit the column faster. Repeated interactions along the length of the column effect a separation of the analytes. Various mixtures of analytes can be analyzed by changing the polarities of the stationary phase and the mobile phase.