Analysts interested in organic molecules like dissolved organic matter or pharmaceuticals should consider quantifying organic molecules with the High Performance Liquid Chromatography (HPLC) Instrument. There are three different HPLC systems in the engineering laboratories. All HPLC’s measure low level organic compounds in surface water, groundwater, and drinking water. The instruments can separate molecules from each other based on physicochemical properties like molecular size, polarity, and electrical charge depending on the solvents used to carry the sample and the type of separator column. After the molecules are separated, the HPLC Agilent 1220 series quantifies molecules with a UV-VIS detector. The UV-VIS detector uses software to create peaks for each molecule, which can be quantified by comparing peak areas of samples to peak areas of calibration standards.