Liquid chromatography (LC) columns, also known as high performance liquid chromatography (HPLC) columns, are used to separate the individual components of a sample for either purification purposes or for analysis. A liquid mobile phase is put through the HPLC column at a high pressure, and the separated components are eluted from the column at different times, allowing for the purified compounds to be put to another use or for the analysis of the chemical compounds in the sample. LC columns are used in the biomedical field to test for, among other things, blood alcohol levels, poisons in the body, and causes of death. Environmental sciences, clinical sciences, and many industries use the LC column to purify or find impurities in a substance. The type of high performance liquid chromatography column one uses depends on the type of sample that will be run through it. HPLC columns can be of different sizes and made of either glass or metal. LC columns can also have normal phase or reverse phase stationary phases.